% podman-run(1)

## NAME
podman\-run - Run a command in a new container

## SYNOPSIS
**podman run** [*options*] *image* [*command* [*arg* ...]]

**podman container run** [*options*] *image* [*command* [*arg* ...]]

## DESCRIPTION

Run a process in a new container. **podman run** starts a process with its own
file system, its own networking, and its own isolated process tree. The _image_
which starts the process may define defaults related to the process that will be
run in the container, the networking to expose, and more, but **podman run**
gives final control to the operator or administrator who starts the container
from the image. For that reason **podman run** has more options than any other
Podman command.

If the _image_ is not already loaded then **podman run** will pull the _image_, and
all image dependencies, from the repository in the same way running **podman
pull** _image_ , before it starts the container from that image.

Several files will be automatically created within the container. These include
_/etc/hosts_, _/etc/hostname_, and _/etc/resolv.conf_ to manage networking.
These will be based on the host's version of the files, though they can be
customized with options (for example, **--dns** will override the host's DNS
servers in the created _resolv.conf_). Additionally, a container environment
file is created in each container to indicate to programs they are running in a
container. This file is located at _/run/.containerenv_. When using the
--privileged flag the .containerenv contains name/value pairs indicating the
container engine version, whether the engine is running in rootless mode, the
container name and id, as well as the image name and id that the container is based on.

When running from a user defined network namespace, the _/etc/netns/NSNAME/resolv.conf_
will be used if it exists, otherwise _/etc/resolv.conf_ will be used.

Default settings are defined in `containers.conf`. Most settings for remote
connections use the servers containers.conf, except when documented in man
pages.

## IMAGE

  The image is specified using transport:path format. If no transport is specified, the `docker` (container registry)
transport will be used by default. For remote Podman, including Mac and Windows (excluding WSL2) machines, `docker` is the only allowed transport.

  **dir:**_path_
  An existing local directory _path_ storing the manifest, layer tarballs and signatures as individual files. This
is a non-standardized format, primarily useful for debugging or noninvasive container inspection.

    $ podman save --format docker-dir fedora -o /tmp/fedora
    $ podman run dir:/tmp/fedora echo hello

  **docker://**_docker-reference_ (Default)
  An image reference stored in a remote container image registry. Example: "quay.io/podman/stable:latest".
The reference can include a path to a specific registry; if it does not, the
registries listed in registries.conf will be queried to find a matching image.
By default, credentials from `podman login` (stored at
$XDG_RUNTIME_DIR/containers/auth.json by default) will be used to authenticate;
otherwise it falls back to using credentials in $HOME/.docker/config.json.

    $ podman run registry.fedoraproject.org/fedora:latest echo hello

  **docker-archive:**_path_[**:**_docker-reference_]
An image stored in the `docker save` formatted file. _docker-reference_ is only used when creating such a
file, and it must not contain a digest.

    $ podman save --format docker-archive fedora -o /tmp/fedora
    $ podman run docker-archive:/tmp/fedora echo hello

  **docker-daemon:**_docker-reference_
  An image in _docker-reference_ format stored in the docker daemon internal storage. The _docker-reference_ can also be an image ID (docker-daemon:algo:digest).

    $ sudo docker pull fedora
    $ sudo podman run docker-daemon:docker.io/library/fedora echo hello

  **oci-archive:**_path_**:**_tag_
  An image in a directory compliant with the "Open Container Image Layout Specification" at the specified _path_
and specified with a _tag_.

    $ podman save --format oci-archive fedora -o /tmp/fedora
    $ podman run oci-archive:/tmp/fedora echo hello

## OPTIONS
#### **--add-host**=_host_:_ip_

Add a line to container's _/etc/hosts_ for custom host-to-IP mapping.
This option can be set multiple times.

#### **--annotation**=_key_=_value_

Add an annotation to the container.
This option can be set multiple times.

#### **--arch**=*ARCH*
Override the architecture, defaults to hosts, of the image to be pulled. For example, `arm`.

#### **--attach**, **-a**=**stdin**|**stdout**|**stderr**

Attach to STDIN, STDOUT or STDERR.

In foreground mode (the default when **-d**
is not specified), **podman run** can start the process in the container
and attach the console to the process's standard input, output, and
error. It can even pretend to be a TTY (this is what most commandline
executables expect) and pass along signals. The **-a** option can be set for
each of **stdin**, **stdout**, and **stderr**.

#### **--authfile**[=*path*]

Path to the authentication file. Default is *${XDG_RUNTIME_DIR}/containers/auth.json*.

Note: You can also override the default path of the authentication file by setting the **REGISTRY_AUTH_FILE**
environment variable.

#### **--blkio-weight**=*weight*

Block IO relative weight. The _weight_ is a value between **10** and **1000**.

#### **--blkio-weight-device**=*device*:*weight*

Block IO relative device weight.

#### **--cap-add**=*capability*

Add Linux capabilities.

#### **--cap-drop**=*capability*

Drop Linux capabilities.

#### **--cgroup-conf**=*KEY=VALUE*

When running on cgroup v2, specify the cgroup file to write to and its value. For example **--cgroup-conf=memory.high=1073741824** sets the memory.high limit to 1GB.

#### **--cgroup-parent**=*path*

Path to cgroups under which the cgroup for the container will be created. If the path is not absolute, the path is considered to be relative to the cgroups path of the init process. Cgroups will be created if they do not already exist.

#### **--cgroupns**=*mode*

Set the cgroup namespace mode for the container.

- **host**: use the host's cgroup namespace inside the container.
- **container:**_id_: join the namespace of the specified container.
- **private**: create a new cgroup namespace.
- **ns:**_path_: join the namespace at the specified path.

If the host uses cgroups v1, the default is set to **host**. On cgroups v2, the default is **private**.

#### **--cgroups**=**enabled**|**disabled**|**no-conmon**|**split**

Determines whether the container will create CGroups.

Default is **enabled**.

The **enabled** option will create a new cgroup under the cgroup-parent.
The **disabled** option will force the container to not create CGroups, and thus conflicts with CGroup options (**--cgroupns** and **--cgroup-parent**).
The **no-conmon** option disables a new CGroup only for the **conmon** process.
The **split** option splits the current CGroup in two sub-cgroups: one for conmon and one for the container payload. It is not possible to set **--cgroup-parent** with **split**.

#### **--chrootdirs**=*path*

Path to a directory inside the container that should be treated as a `chroot` directory.
Any Podman managed file (e.g., /etc/resolv.conf, /etc/hosts, etc/hostname) that is mounted into the root directory will be mounted into that location as well.
Multiple directories should be separated with a comma.

#### **--cidfile**=*file*

Write the container ID to *file*.

#### **--conmon-pidfile**=*file*

Write the pid of the **conmon** process to a file. As **conmon** runs in a separate process than Podman, this is necessary when using systemd to restart Podman containers.
(This option is not available with the remote Podman client, including Mac and Windows (excluding WSL2) machines)

#### **--cpu-period**=*limit*

Set the CPU period for the Completely Fair Scheduler (CFS), which is a
duration in microseconds. Once the container's CPU quota is used up, it will
not be scheduled to run until the current period ends. Defaults to 100000
microseconds.

On some systems, changing the CPU limits may not be allowed for non-root
users. For more details, see
https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-cpu-limits-fails-with-a-permissions-error

#### **--cpu-quota**=*limit*

Limit the CPU Completely Fair Scheduler (CFS) quota.

Limit the container's CPU usage. By default, containers run with the full
CPU resource. The limit is a number in microseconds. If you provide a number,
the container will be allowed to use that much CPU time until the CPU period
ends (controllable via **--cpu-period**).

On some systems, changing the CPU limits may not be allowed for non-root
users. For more details, see
https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-cpu-limits-fails-with-a-permissions-error

#### **--cpu-rt-period**=*microseconds*

Limit the CPU real-time period in microseconds.

Limit the container's Real Time CPU usage. This flag tell the kernel to restrict the container's Real Time CPU usage to the period you specify.

This flag is not supported on cgroups V2 systems.

#### **--cpu-rt-runtime**=*microseconds*

Limit the CPU real-time runtime in microseconds.

Limit the containers Real Time CPU usage. This flag tells the kernel to limit the amount of time in a given CPU period Real Time tasks may consume. Ex:
Period of 1,000,000us and Runtime of 950,000us means that this container could consume 95% of available CPU and leave the remaining 5% to normal priority tasks.

The sum of all runtimes across containers cannot exceed the amount allotted to the parent cgroup.

This flag is not supported on cgroups V2 systems.

#### **--cpu-shares**=*shares*

CPU shares (relative weight).

By default, all containers get the same proportion of CPU cycles. This proportion
can be modified by changing the container's CPU share weighting relative
to the combined weight of all the running containers. Default weight is **1024**.

The proportion will only apply when CPU-intensive processes are running.
When tasks in one container are idle, other containers can use the
left-over CPU time. The actual amount of CPU time will vary depending on
the number of containers running on the system.

For example, consider three containers, one has a cpu-share of 1024 and
two others have a cpu-share setting of 512. When processes in all three
containers attempt to use 100% of CPU, the first container would receive
50% of the total CPU time. If you add a fourth container with a cpu-share
of 1024, the first container only gets 33% of the CPU. The remaining containers
receive 16.5%, 16.5% and 33% of the CPU.

On a multi-core system, the shares of CPU time are distributed over all CPU
cores. Even if a container is limited to less than 100% of CPU time, it can
use 100% of each individual CPU core.

For example, consider a system with more than three cores. If you start one
container **{C0}** with **--cpu-shares=512** running one process, and another container
**{C1}** with **--cpu-shares=1024** running two processes, this can result in the following
division of CPU shares:

| PID  |  container  | CPU     | CPU share    |
| ---- | ----------- | ------- | ------------ |
| 100  |  {C0}       | 0       | 100% of CPU0 |
| 101  |  {C1}       | 1       | 100% of CPU1 |
| 102  |  {C1}       | 2       | 100% of CPU2 |

#### **--cpus**=*number*

Number of CPUs. The default is *0.0* which means no limit. This is shorthand
for **--cpu-period** and **--cpu-quota**, so you may only set either
#### **--cpus** or **--cpu-period** and **--cpu-quota**.

On some systems, changing the CPU limits may not be allowed for non-root
users. For more details, see
https://github.com/containers/podman/blob/main/troubleshooting.md#26-running-containers-with-cpu-limits-fails-with-a-permissions-error

#### **--cpuset-cpus**=*number*

CPUs in which to allow execution. Can be specified as a comma-separated list
(e.g. **0,1**), as a range (e.g. **0-3**), or any combination thereof
(e.g. **0-3,7,11-15**).

#### **--cpuset-mems**=*nodes*

Memory nodes (MEMs) in which to allow execution. Only effective on NUMA systems.

For example, if you have four memory nodes (0-3) on your system, use **--cpuset-mems=0,1**
to only use memory from the first two memory nodes.

#### **--detach**, **-d**

Detached mode: run the container in the background and print the new container ID. The default is *false*.

At any time you can run **podman ps** in
the other shell to view a list of the running containers. You can reattach to a
detached container with **podman attach**.

When attached in the tty mode, you can detach from the container (and leave it
running) using a configurable key sequence. The default sequence is `ctrl-p,ctrl-q`.
Configure the keys sequence using the **--detach-keys** option, or specifying
it in the **containers.conf** file: see **containers.conf(5)** for more information.

#### **--detach-keys**=*sequence*

Specify the key sequence for detaching a container. Format is a single character `[a-Z]` or one or more `ctrl-<value>` characters where `<value>` is one of: `a-z`, `@`, `^`, `[`, `,` or `_`. Specifying "" will set the sequence to the default value of *ctrl-p,ctrl-q*.

This option can also be set in **containers.conf**(5) file.

#### **--device**=_host-device_[**:**_container-device_][**:**_permissions_]

Add a host device to the container. Optional *permissions* parameter
can be used to specify device permissions, it is combination of
**r** for read, **w** for write, and **m** for **mknod**(2).

Example: **--device=/dev/sdc:/dev/xvdc:rwm**.

Note: if _host_device_ is a symbolic link then it will be resolved first.
The container will only store the major and minor numbers of the host device.

Note: if the user only has access rights via a group, accessing the device
from inside a rootless container will fail. Use the `--group-add keep-groups`
flag to pass the user's supplementary group access into the container.

Podman may load kernel modules required for using the specified
device. The devices that Podman will load modules when necessary are:
/dev/fuse.

#### **--device-cgroup-rule**=rule

Add a rule to the cgroup allowed devices list

#### **--device-read-bps**=_path_:_rate_

Limit read rate (in bytes per second) from a device (e.g. **--device-read-bps=/dev/sda:1mb**).

#### **--device-read-iops**=_path_:_rate_

Limit read rate (in IO operations per second) from a device (e.g. **--device-read-iops=/dev/sda:1000**).

#### **--device-write-bps**=_path_:_rate_

Limit write rate (in bytes per second) to a device (e.g. **--device-write-bps=/dev/sda:1mb**).

#### **--device-write-iops**=_path_:_rate_

Limit write rate (in IO operations per second) to a device (e.g. **--device-write-iops=/dev/sda:1000**).

#### **--disable-content-trust**

This is a Docker specific option to disable image verification to a Docker
registry and is not supported by Podman. This flag is a NOOP and provided
solely for scripting compatibility.

#### **--dns**=*ipaddr*

Set custom DNS servers. Invalid if using **--dns** with **--network** that is set to **none** or **container:**_id_.

This option can be used to override the DNS
configuration passed to the container. Typically this is necessary when the
host DNS configuration is invalid for the container (e.g., **127.0.0.1**). When this
is the case the **--dns** flag is necessary for every run.

The special value **none** can be specified to disable creation of _/etc/resolv.conf_ in the container by Podman.
The _/etc/resolv.conf_ file in the image will be used without changes.

#### **--dns-opt**=*option*

Set custom DNS options. Invalid if using **--dns-opt** with **--network** that is set to **none** or **container:**_id_.

#### **--dns-search**=*domain*

Set custom DNS search domains. Invalid if using **--dns-search** and **--network** that is set to **none** or **container:**_id_.
Use **--dns-search=.** if you don't wish to set the search domain.

#### **--entrypoint**=*"command"* | *'["command", "arg1", ...]'*

Overwrite the default ENTRYPOINT of the image.

This option allows you to overwrite the default entrypoint of the image.

The ENTRYPOINT of an image is similar to a COMMAND
because it specifies what executable to run when the container starts, but it is
(purposely) more difficult to override. The ENTRYPOINT gives a container its
default nature or behavior, so that when you set an ENTRYPOINT you can run the
container as if it were that binary, complete with default options, and you can
pass in more options via the COMMAND. But, sometimes an operator may want to run
something else inside the container, so you can override the default ENTRYPOINT
at runtime by using a **--entrypoint** and a string to specify the new
ENTRYPOINT.

You need to specify multi option commands in the form of a json string.

#### **--env**, **-e**=*env*

Set environment variables.

This option allows arbitrary environment variables that are available for the process to be launched inside of the container. If an environment variable is specified without a value, Podman will check the host environment for a value and set the variable only if it is set on the host. If an environment variable ending in __*__ is specified, Podman will search the host environment for variables starting with the prefix and will add those variables to the container. If an environment variable with a trailing __*__ is specified, then a value must be supplied.

See [**Environment**](#environment) note below for precedence and examples.

#### **--env-file**=*file*

Read in a line delimited file of environment variables. See **Environment** note below for precedence.

#### **--env-host**

Use host environment inside of the container. See **Environment** note below for precedence. (This option is not available with the remote Podman client, including Mac and Windows (excluding WSL2) machines)

#### **--expose**=*port*

Expose a port, or a range of ports (e.g. **--expose=3300-3310**) to set up port redirection
on the host system.

#### **--gidmap**=*container_gid*:*host_gid*:*amount*

Run the container in a new user namespace using the supplied mapping. This option conflicts with the **--userns** and **--subgidname** flags.
This option can be passed several times to map different ranges. If calling **podman run** as an unprivileged user, the user needs to have the right to use the mapping. See **subuid**(5).
The example maps gids **0-1999** in the container to the gids **30000-31999** on the host: **--gidmap=0:30000:2000**.

**Important note:** The new user namespace mapping based on **--gidmap** is based on the initial mapping made in the  _/etc/subgid_  file.
Assuming there is a  _/etc/subgid_  mapping **groupname:100000:65536**, then **groupname** is initially mapped to a namespace starting with
gid **100000** for **65536** ids. From here the **--gidmap** mapping to the new namespace starts from **0** again, but is based on the initial mapping.
Meaning **groupname** is initially mapped to gid **100000** which is referenced as **0** in the following **--gidmap** mapping. In terms of the example
above: The group **groupname** is mapped to group **100000** of the initial namespace then the
**30000**st id of this namespace (which is gid 130000 in this namespace) is mapped to container namespace group id **0**. (groupname -> 100000 / 30000 -> 0)

Note: the **--gidmap** flag cannot be called in conjunction with the **--pod** flag as a gidmap cannot be set on the container level when in a pod.

#### **--group-add**=*group|keep-groups*

Assign additional groups to the primary user running within the container process.

- `keep-groups` is a special flag that tells Podman to keep the supplementary group access.

Allows container to use the user's supplementary group access. If file systems or
devices are only accessible by the rootless user's group, this flag tells the OCI
runtime to pass the group access into the container. Currently only available
with the `crun` OCI runtime. Note: `keep-groups` is exclusive, you cannot add any other groups
with this flag. (Not available for remote commands, including Mac and Windows (excluding WSL2) machines)

#### **--health-cmd**=*"command"* | *'["command", "arg1", ...]'*

Set or alter a healthcheck command for a container. The command is a command to be executed inside your
container that determines your container health. The command is required for other healthcheck options
to be applied. A value of **none** disables existing healthchecks.

Multiple options can be passed in the form of a JSON array; otherwise, the command will be interpreted
as an argument to **/bin/sh -c**.

#### **--health-interval**=*interval*

Set an interval for the healthchecks. An _interval_ of **disable** results in no automatic timer setup. The default is **30s**.

#### **--health-retries**=*retries*

The number of retries allowed before a healthcheck is considered to be unhealthy. The default value is **3**.

#### **--health-start-period**=*period*

The initialization time needed for a container to bootstrap. The value can be expressed in time format like
**2m3s**. The default value is **0s**.

#### **--health-timeout**=*timeout*

The maximum time allowed to complete the healthcheck before an interval is considered failed. Like start-period, the
value can be expressed in a time format such as **1m22s**. The default value is **30s**.

#### **--help**

Print usage statement

#### **--hostname**=*name*, **-h**

Container host name

Sets the container host name that is available inside the container. Can only be used with a private UTS namespace `--uts=private` (default). If `--pod` is specified and the pod shares the UTS namespace (default) the pod's hostname will be used.

#### **--hostuser**=*name*

Add a user account to /etc/passwd from the host to the container. The Username
or UID must exist on the host system.

#### **--http-proxy**

By default proxy environment variables are passed into the container if set
for the Podman process. This can be disabled by setting the value to **false**.
The environment variables passed in include **http_proxy**,
**https_proxy**, **ftp_proxy**, **no_proxy**, and also the upper case versions of
those. This option is only needed when the host system must use a proxy but
the container should not use any proxy. Proxy environment variables specified
for the container in any other way will override the values that would have
been passed through from the host. (Other ways to specify the proxy for the
container include passing the values with the **--env** flag, or hard coding the
proxy environment at container build time.) (This option is not available with the remote Podman client, including Mac and Windows (excluding WSL2) machines)

Defaults to **true**.

#### **--image-volume**, **builtin-volume**=**bind**|**tmpfs**|**ignore**

Tells Podman how to handle the builtin image volumes. Default is **bind**.

- **bind**: An anonymous named volume will be created and mounted into the container.
- **tmpfs**: The volume is mounted onto the container as a tmpfs, which allows the users to create
content that disappears when the container is stopped.
- **ignore**: All volumes are just ignored and no action is taken.

#### **--init**

Run an init inside the container that forwards signals and reaps processes.

#### **--init-path**=*path*

Path to the container-init binary.

#### **--interactive**, **-i**

When set to **true**, keep stdin open even if not attached. The default is **false**.

#### **--ip**=*ipv4*

Specify a static IPv4 address for the container, for example **10.88.64.128**.
This option can only be used if the container is joined to only a single network - i.e., **--network=network-name** is used at most once -
and if the container is not joining another container's network namespace via **--network=container:_id_**.
The address must be within the network's IP address pool (default **10.88.0.0/16**).

To specify multiple static IP addresses per container, set multiple networks using the **--network** option with a static IP address specified for each using the `ip` mode for that option.

#### **--ip6**=*ipv6*

Specify a static IPv6 address for the container, for example **fd46:db93:aa76:ac37::10**.
This option can only be used if the container is joined to only a single network - i.e., **--network=network-name** is used at most once -
and if the container is not joining another container's network namespace via **--network=container:_id_**.
The address must be within the network's IPv6 address pool.

To specify multiple static IPv6 addresses per container, set multiple networks using the **--network** option with a static IPv6 address specified for each using the `ip6` mode for that option.

#### **--ipc**=*mode*

Set the IPC namespace mode for a container. The default is to create
a private IPC namespace.

- **container:**_id_: reuses another container shared memory, semaphores and message queues
- **host**: use the host shared memory,semaphores and message queues inside the container. Note: the host mode gives the container full access to local shared memory and is therefore considered insecure.
- **ns:**_path_: path to an IPC namespace to join.

#### **--label**, **-l**=*key*=*value*

Add metadata to a container.

#### **--label-file**=*file*

Read in a line-delimited file of labels.

#### **--link-local-ip**=*ip*

Not implemented.

#### **--log-driver**="*driver*"

Logging driver for the container. Currently available options are **k8s-file**, **journald**, **none** and **passthrough**, with **json-file** aliased to **k8s-file** for scripting compatibility. (Default journald)

The podman info command below will display the default log-driver for the system.
```
$ podman info --format '{{ .Host.LogDriver }}'
journald
```
The **passthrough** driver passes down the standard streams (stdin, stdout, stderr) to the
container.  It is not allowed with the remote Podman client, including Mac and Windows (excluding WSL2) machines, and on a tty, since it is
vulnerable to attacks via TIOCSTI.


#### **--log-opt**=*name*=*value*

Logging driver specific options.

Set custom logging configuration. The following *name*s are supported:

**path**: specify a path to the log file
    (e.g. **--log-opt path=/var/log/container/mycontainer.json**);

**max-size**: specify a max size of the log file
    (e.g. **--log-opt max-size=10mb**);

**tag**: specify a custom log tag for the container
   (e.g. **--log-opt tag="{{.ImageName}}"**.

This option is currently supported only by the **journald** log driver.

#### **--mac-address**=*address*

Container network interface MAC address (e.g. 92:d0:c6:0a:29:33)
This option can only be used if the container is joined to only a single network - i.e., **--network=_network-name_** is used at most once -
and if the container is not joining another container's network namespace via **--network=container:_id_**.

Remember that the MAC address in an Ethernet network must be unique.
The IPv6 link-local address will be based on the device's MAC address
according to RFC4862.

To specify multiple static MAC addresses per container, set multiple networks using the **--network** option with a static MAC address specified for each using the `mac` mode for that option.

#### **--memory**, **-m**=_number_[_unit_]

Memory limit. A _unit_ can be **b** (bytes), **k** (kilobytes), **m** (megabytes), or **g** (gigabytes).

Allows you to constrain the memory available to a container. If the host
supports swap memory, then the **-m** memory setting can be larger than physical
RAM. If a limit of 0 is specified (not using **-m**), the container's memory is
not limited. The actual limit may be rounded up to a multiple of the operating
system's page size (the value would be very large, that's millions of trillions).

#### **--memory-reservation**=_number_[_unit_]

Memory soft limit. A _unit_ can be **b** (bytes), **k** (kilobytes), **m** (megabytes), or **g** (gigabytes).

After setting memory reservation, when the system detects memory contention
or low memory, containers are forced to restrict their consumption to their
reservation. So you should always set the value below **--memory**, otherwise the
hard limit will take precedence. By default, memory reservation will be the same
as memory limit.

#### **--memory-swap**=_number_[_unit_]

A limit value equal to memory plus swap.
A _unit_ can be **b** (bytes), **k** (kilobytes), **m** (megabytes), or **g** (gigabytes).

Must be used with the **-m** (**--memory**) flag.
The argument value should always be larger than that of
 **-m** (**--memory**) By default, it is set to double
the value of **--memory**.

Set _number_ to **-1** to enable unlimited swap.

#### **--memory-swappiness**=*number*

Tune a container's memory swappiness behavior. Accepts an integer between *0* and *100*.

This flag is not supported on cgroups V2 systems.

#### **--mount**=*type=TYPE,TYPE-SPECIFIC-OPTION[,...]*

Attach a filesystem mount to the container

Current supported mount TYPEs are **bind**, **volume**, **image**, **tmpfs** and **devpts**. <sup>[[1]](#Footnote1)</sup>

       e.g.

       type=bind,source=/path/on/host,destination=/path/in/container

       type=bind,src=/path/on/host,dst=/path/in/container,relabel=shared

       type=bind,src=/path/on/host,dst=/path/in/container,relabel=shared,U=true

       type=volume,source=vol1,destination=/path/in/container,ro=true

       type=tmpfs,tmpfs-size=512M,destination=/path/in/container

       type=image,source=fedora,destination=/fedora-image,rw=true

       type=devpts,destination=/dev/pts

       Common Options:

	      · src, source: mount source spec for bind and volume. Mandatory for bind.

	      · dst, destination, target: mount destination spec.

       Options specific to volume:

	      · ro, readonly: true or false (default).

	      . U, chown: true or false (default). Change recursively the owner and group of the source volume based on the UID and GID of the container.

	      · idmap: true or false (default).  If specified, create an idmapped mount to the target user namespace in the container.

       Options specific to image:

	      · rw, readwrite: true or false (default).

       Options specific to bind:

	      · ro, readonly: true or false (default).

	      · bind-propagation: shared, slave, private, unbindable, rshared, rslave, runbindable, or rprivate(default). See also mount(2).

	      . bind-nonrecursive: do not setup a recursive bind mount. By default it is recursive.

	      . relabel: shared, private.

	      · idmap: true or false (default).  If specified, create an idmapped mount to the target user namespace in the container.

	      . U, chown: true or false (default). Change recursively the owner and group of the source volume based on the UID and GID of the container.

       Options specific to tmpfs:

	      · ro, readonly: true or false (default).

	      · tmpfs-size: Size of the tmpfs mount in bytes. Unlimited by default in Linux.

	      · tmpfs-mode: File mode of the tmpfs in octal. (e.g. 700 or 0700.) Defaults to 1777 in Linux.

	      · tmpcopyup: Enable copyup from the image directory at the same location to the tmpfs. Used by default.

	      · notmpcopyup: Disable copying files from the image to the tmpfs.

	      . U, chown: true or false (default). Change recursively the owner and group of the source volume based on the UID and GID of the container.

       Options specific to devpts:

	      · uid: UID of the file owner (default 0).

	      · gid: GID of the file owner (default 0).

	      · mode: permission mask for the file (default 600).

	      · max: maximum number of PTYs (default 1048576).

#### **--name**=*name*

Assign a name to the container.

The operator can identify a container in three ways:

- UUID long identifier (“f78375b1c487e03c9438c729345e54db9d20cfa2ac1fc3494b6eb60872e74778”);
- UUID short identifier (“f78375b1c487”);
- Name (“jonah”).

Podman generates a UUID for each container, and if a name is not assigned
to the container with **--name** then it will generate a random
string name. The name is useful any place you need to identify a container.
This works for both background and foreground containers.

#### **--network**=*mode*, **--net**

Set the network mode for the container. Invalid if using **--dns**, **--dns-opt**, or **--dns-search** with **--network** set to **none** or **container:**_id_. If used together with **--pod**, the container will not join the pod's network namespace.

Valid _mode_ values are:

- **bridge[:OPTIONS,...]**: Create a network stack on the default bridge. This is the default for rootfull containers. It is possible to specify these additional options:
  - **alias=name**: Add network-scoped alias for the container.
  - **ip=IPv4**: Specify a static ipv4 address for this container.
  - **ip=IPv6**: Specify a static ipv6 address for this container.
  - **mac=MAC**: Specify a static mac address for this container.
  - **interface_name**: Specify a name for the created network interface inside the container.

  For example to set a static ipv4 address and a static mac address, use `--network bridge:ip=10.88.0.10,mac=44:33:22:11:00:99`.
- \<network name or ID\>[:OPTIONS,...]: Connect to a user-defined network; this is the network name or ID from a network created by **[podman network create](podman-network-create.1.md)**. Using the network name implies the bridge network mode. It is possible to specify the same options described under the bridge mode above. You can use the **--network** option multiple times to specify additional networks.
- **none**: Create a network namespace for the container but do not configure network interfaces for it, thus the container has no network connectivity.
- **container:**_id_: Reuse another container's network stack.
- **host**: Do not create a network namespace, the container will use the host's network. Note: The host mode gives the container full access to local system services such as D-bus and is therefore considered insecure.
- **ns:**_path_: Path to a network namespace to join.
- **private**: Create a new namespace for the container. This will use the **bridge** mode for rootfull containers and **slirp4netns** for rootless ones.
- **slirp4netns[:OPTIONS,...]**: use **slirp4netns**(1) to create a user network stack. This is the default for rootless containers. It is possible to specify these additional options:
  - **allow_host_loopback=true|false**: Allow the slirp4netns to reach the host loopback IP (`10.0.2.2`, which is added to `/etc/hosts` as `host.containers.internal` for your convenience). Default is false.
  - **mtu=MTU**: Specify the MTU to use for this network. (Default is `65520`).
  - **cidr=CIDR**: Specify ip range to use for this network. (Default is `10.0.2.0/24`).
  - **enable_ipv6=true|false**: Enable IPv6. Default is false. (Required for `outbound_addr6`).
  - **outbound_addr=INTERFACE**: Specify the outbound interface slirp should bind to (ipv4 traffic only).
  - **outbound_addr=IPv4**: Specify the outbound ipv4 address slirp should bind to.
  - **outbound_addr6=INTERFACE**: Specify the outbound interface slirp should bind to (ipv6 traffic only).
  - **outbound_addr6=IPv6**: Specify the outbound ipv6 address slirp should bind to.
  - **port_handler=rootlesskit**: Use rootlesskit for port forwarding. Default.
  Note: Rootlesskit changes the source IP address of incoming packets to an IP address in the container network namespace, usually `10.0.2.100`. If your application requires the real source IP address, e.g. web server logs, use the slirp4netns port handler. The rootlesskit port handler is also used for rootless containers when connected to user-defined networks.
  - **port_handler=slirp4netns**: Use the slirp4netns port forwarding, it is slower than rootlesskit but preserves the correct source IP address. This port handler cannot be used for user-defined networks.

#### **--network-alias**=*alias*

Add a network-scoped alias for the container, setting the alias for all networks that the container joins. To set a name only for a specific network, use the alias option as described under the **--network** option.
Network aliases work only with the bridge networking mode. This option can be specified multiple times.
NOTE: A container will only have access to aliases on the first network that it joins. This is a limitation that will be removed in a later release.

#### **--no-healthcheck**

Disable any defined healthchecks for container.

#### **--no-hosts**

Do not create _/etc/hosts_ for the container.

By default, Podman will manage _/etc/hosts_, adding the container's own IP address and any hosts from **--add-host**.
#### **--no-hosts** disables this, and the image's _/etc/hosts_ will be preserved unmodified.
This option conflicts with **--add-host**.

#### **--oom-kill-disable**

Whether to disable OOM Killer for the container or not.

This flag is not supported on cgroups V2 systems.

#### **--oom-score-adj**=*num*

Tune the host's OOM preferences for containers (accepts values from **-1000** to **1000**).

#### **--os**=*OS*
Override the OS, defaults to hosts, of the image to be pulled. For example, `windows`.

#### **--passwd**

Allow Podman to add entries to /etc/passwd and /etc/group when used in conjunction with the --user option.
This is used to override the Podman provided user setup in favor of entrypoint configurations such as libnss-extrausers.

#### **--personality**=*persona*

Personality sets the execution domain via Linux personality(2).

#### **--pid**=*mode*

Set the PID namespace mode for the container.
The default is to create a private PID namespace for the container.

- **container:**_id_: join another container's PID namespace;
- **host**: use the host's PID namespace for the container. Note the host mode gives the container full access to local PID and is therefore considered insecure;
- **private**: create a new namespace for the container (default)
- **ns:**_path_: join the specified PID namespace.

#### **--pidfile**=*path*

When the pidfile location is specified, the container process' PID will be written to the pidfile. (This option is not available with the remote Podman client, including Mac and Windows (excluding WSL2) machines)
If the pidfile option is not specified, the container process' PID will be written to /run/containers/storage/${storage-driver}-containers/$CID/userdata/pidfile.

After the container is started, the location for the pidfile can be discovered with the following `podman inspect` command:

    $ podman inspect --format '{{ .PidFile }}' $CID
    /run/containers/storage/${storage-driver}-containers/$CID/userdata/pidfile

#### **--pids-limit**=*limit*

Tune the container's pids limit. Set to **-1** to have unlimited pids for the container. The default is **4096** on systems that support "pids" cgroup controller.

#### **--platform**=*OS/ARCH*

Specify the platform for selecting the image.  (Conflicts with --arch and --os)
The `--platform` option can be used to override the current architecture and operating system.

#### **--pod**=*name*

Run container in an existing pod. If you want Podman to make the pod for you, prefix the pod name with **new:**.
To make a pod with more granular options, use the **podman pod create** command before creating a container.
If a container is run with a pod, and the pod has an infra-container, the infra-container will be started before the container is.

#### **--pod-id-file**=*path*

Run container in an existing pod and read the pod's ID from the specified file.
If a container is run within a pod, and the pod has an infra-container, the infra-container will be started before the container is.

#### **--preserve-fds**=*N*

Pass down to the process N additional file descriptors (in addition to 0, 1, 2).
The total FDs will be 3+N. (This option is not available with the remote Podman client, including Mac and Windows (excluding WSL2) machines)

#### **--privileged**

Give extended privileges to this container. The default is **false**.

By default, Podman containers are unprivileged (**=false**) and cannot, for
example, modify parts of the operating system. This is because by default a
container is only allowed limited access to devices. A "privileged" container
is given the same access to devices as the user launching the container.

A privileged container turns off the security features that isolate the
container from the host. Dropped Capabilities, limited devices, read-only mount
points, Apparmor/SELinux separation, and Seccomp filters are all disabled.

Rootless containers cannot have more privileges than the account that launched them.

#### **--publish**, **-p**=_ip_:_hostPort_:_containerPort_ | _ip_::_containerPort_ | _hostPort_:_containerPort_ | _containerPort_

Publish a container's port, or range of ports, to the host.

Both hostPort and containerPort can be specified as a range of ports.

When specifying ranges for both, the number of container ports in the range must match the number of host ports in the range.

If host IP is set to 0.0.0.0 or not set at all, the port will be bound on all IPs on the host.

Host port does not have to be specified (e.g. `podman run -p 127.0.0.1::80`).
If it is not, the container port will be randomly assigned a port on the host.

Use **podman port** to see the actual mapping: **podman port $CONTAINER $CONTAINERPORT**.

**Note:** if a container will be run within a pod, it is not necessary to publish the port for
the containers in the pod. The port must only be published by the pod itself. Pod network
stacks act like the network stack on the host - you have a variety of containers in the pod,
and programs in the container, all sharing a single interface and IP address, and
associated ports. If one container binds to a port, no other container can use that port
within the pod while it is in use. Containers in the pod can also communicate over localhost
by having one container bind to localhost in the pod, and another connect to that port.

#### **--publish-all**, **-P**

Publish all exposed ports to random ports on the host interfaces. The default is **false**.

When set to **true**, publish all exposed ports to the host interfaces. The
default is **false**. If the operator uses **-P** (or **-p**) then Podman will make the
exposed port accessible on the host and the ports will be available to any
client that can reach the host.

When using this option, Podman will bind any exposed port to a random port on the host
within an ephemeral port range defined by */proc/sys/net/ipv4/ip_local_port_range*.
To find the mapping between the host ports and the exposed ports, use **podman port**.

#### **--pull**=**always**|**missing**|**never**

Pull image before running. The default is **missing**.

- **missing**: attempt to pull the latest image from the registries listed in registries.conf if a local image does not exist.Raise an error if the image is not in any listed registry and is not present locally.
- **always**: Pull the image from the first registry it is found in as listed in registries.conf. Raise an error if not found in the registries, even if the image is present locally.
- **never**: do not pull the image from the registry, use only the local version. Raise an error if the image is not present locally.

#### **--quiet**, **-q**

Suppress output information when pulling images

#### **--read-only**

Mount the container's root filesystem as read only.

By default a container will have its root filesystem writable allowing processes
to write files anywhere. By specifying the **--read-only** flag, the container will have
its root filesystem mounted as read only prohibiting any writes.

#### **--read-only-tmpfs**

If container is running in **--read-only** mode, then mount a read-write tmpfs on _/run_, _/tmp_, and _/var/tmp_. The default is **true**.

#### **--replace**

If another container with the same name already exists, replace and remove it. The default is **false**.

#### **--requires**=**container**

Specify one or more requirements.
A requirement is a dependency container that will be started before this container.
Containers can be specified by name or ID, with multiple containers being separated by commas.

#### **--restart**=*policy*

Restart policy to follow when containers exit.
Restart policy will not take effect if a container is stopped via the **podman kill** or **podman stop** commands.

Valid _policy_ values are:

- `no`                       : Do not restart containers on exit
- `on-failure[:max_retries]` : Restart containers when they exit with a non-zero exit code, retrying indefinitely or until the optional *max_retries* count is hit
- `always`                   : Restart containers when they exit, regardless of status, retrying indefinitely
- `unless-stopped`           : Identical to **always**

Please note that restart will not restart containers after a system reboot.
If this functionality is required in your environment, you can invoke Podman from a **systemd.unit**(5) file, or create an init script for whichever init system is in use.
To generate systemd unit files, please see **podman generate systemd**.

#### **--rm**

Automatically remove the container when it exits. The default is **false**.

#### **--rmi**

After exit of the container, remove the image unless another
container is using it. The default is *false*.

#### **--rootfs**

If specified, the first argument refers to an exploded container on the file system.

This is useful to run a container without requiring any image management, the rootfs
of the container is assumed to be managed externally.

  `Overlay Rootfs Mounts`

   The `:O` flag tells Podman to mount the directory from the rootfs path as
storage using the `overlay file system`. The container processes
can modify content within the mount point which is stored in the
container storage in a separate directory. In overlay terms, the source
directory will be the lower, and the container storage directory will be the
upper. Modifications to the mount point are destroyed when the container
finishes executing, similar to a tmpfs mount point being unmounted.

Note: On **SELinux** systems, the rootfs needs the correct label, which is by default
**unconfined_u:object_r:container_file_t**.

#### **--sdnotify**=**container**|**conmon**|**ignore**

Determines how to use the NOTIFY_SOCKET, as passed with systemd and Type=notify.

Default is **container**, which means allow the OCI runtime to proxy the socket into the
container to receive ready notification. Podman will set the MAINPID to conmon's pid.
The **conmon** option sets MAINPID to conmon's pid, and sends READY when the container
has started. The socket is never passed to the runtime or the container.
The **ignore** option removes NOTIFY_SOCKET from the environment for itself and child processes,
for the case where some other process above Podman uses NOTIFY_SOCKET and Podman should not use it.

#### **--seccomp-policy**=*policy*

Specify the policy to select the seccomp profile. If set to *image*, Podman will look for a "io.containers.seccomp.profile" label in the container-image config and use its value as a seccomp profile. Otherwise, Podman will follow the *default* policy by applying the default profile unless specified otherwise via *--security-opt seccomp* as described below.

Note that this feature is experimental and may change in the future.

#### **--secret**=*secret*[,opt=opt ...]

Give the container access to a secret. Can be specified multiple times.

A secret is a blob of sensitive data which a container needs at runtime but
should not be stored in the image or in source control, such as usernames and passwords,
TLS certificates and keys, SSH keys or other important generic strings or binary content (up to 500 kb in size).

When secrets are specified as type `mount`, the secrets are copied and mounted into the container when a container is created.
When secrets are specified as type `env`, the secret will be set as an environment variable within the container.
Secrets are written in the container at the time of container creation, and modifying the secret using `podman secret` commands
after the container is created will not affect the secret inside the container.

Secrets and its storage are managed using the `podman secret` command.

Secret Options

- `type=mount|env`    : How the secret will be exposed to the container. Default mount.
- `target=target`     : Target of secret. Defaults to secret name.
- `uid=0`             : UID of secret. Defaults to 0. Mount secret type only.
- `gid=0`             : GID of secret. Defaults to 0. Mount secret type only.
- `mode=0`            : Mode of secret. Defaults to 0444. Mount secret type only.

#### **--security-opt**=*option*

Security Options

- **apparmor=unconfined** : Turn off apparmor confinement for the container
- **apparmor**=_your-profile_ : Set the apparmor confinement profile for the container

- **label=user:**_USER_: Set the label user for the container processes
- **label=role:**_ROLE_: Set the label role for the container processes
- **label=type:**_TYPE_: Set the label process type for the container processes
- **label=level:**_LEVEL_: Set the label level for the container processes
- **label=filetype:**TYPE_: Set the label file type for the container files
- **label=disable**: Turn off label separation for the container

Note: Labeling can be disabled for all containers by setting label=false in the **containers.conf** (`/etc/containers/containers.conf` or `$HOME/.config/containers/containers.conf`) file.

- **mask**=_/path/1:/path/2_: The paths to mask separated by a colon. A masked path
  cannot be accessed inside the container.

- **no-new-privileges**: Disable container processes from gaining additional privileges

- **seccomp=unconfined**: Turn off seccomp confinement for the container.
- **seccomp=profile.json**: JSON file to be used as a seccomp filter. Note that the `io.podman.annotations.seccomp` annotation is set with the specified value as shown in `podman inspect`.

- **proc-opts**=_OPTIONS_ : Comma-separated list of options to use for the /proc mount. More details
  for the possible mount options are specified in the **proc(5)** man page.

- **unmask**=_ALL_ or _/path/1:/path/2_, or shell expanded paths (/proc/*): Paths to unmask separated by a colon. If set to **ALL**, it will unmask all the paths that are masked or made read only by default.
  The default masked paths are **/proc/acpi, /proc/kcore, /proc/keys, /proc/latency_stats, /proc/sched_debug, /proc/scsi, /proc/timer_list, /proc/timer_stats, /sys/firmware, and /sys/fs/selinux.**.  The default paths that are read only are **/proc/asound**, **/proc/bus**, **/proc/fs**, **/proc/irq**, **/proc/sys**, **/proc/sysrq-trigger**, **/sys/fs/cgroup**.

Note: Labeling can be disabled for all containers by setting **label=false** in the **containers.conf**(5) file.

#### **--shm-size**=_number_[_unit_]

Size of _/dev/shm_. A _unit_ can be **b** (bytes), **k** (kilobytes), **m** (megabytes), or **g** (gigabytes).
If you omit the unit, the system uses bytes. If you omit the size entirely, the default is **64m**.
When _size_ is **0**, there is no limit on the amount of memory used for IPC by the container.

#### **--sig-proxy**

Sets whether the signals sent to the **podman run** command are proxied to the container process. SIGCHLD, SIGSTOP, and SIGKILL are not proxied. The default is **true**.

#### **--stop-signal**=*signal*

Signal to stop a container. Default is **SIGTERM**.

#### **--stop-timeout**=*seconds*

Timeout to stop a container. Default is **10**.
Remote connections use local containers.conf for defaults

#### **--subgidname**=*name*

Run the container in a new user namespace using the map with _name_ in the _/etc/subgid_ file.
If calling **podman run** as an unprivileged user, the user needs to have the right to use the mapping. See **subgid**(5).
This flag conflicts with **--userns** and **--gidmap**.

#### **--subuidname**=*name*

Run the container in a new user namespace using the map with _name_ in the _/etc/subuid_ file.
If calling **podman run** as an unprivileged user, the user needs to have the right to use the mapping. See **subuid**(5).
This flag conflicts with **--userns** and **--uidmap**.

#### **--sysctl**=_name_=_value_

Configure namespaced kernel parameters at runtime.

For the IPC namespace, the following sysctls are allowed:

- kernel.msgmax
- kernel.msgmnb
- kernel.msgmni
- kernel.sem
- kernel.shmall
- kernel.shmmax
- kernel.shmmni
- kernel.shm_rmid_forced
- Sysctls beginning with fs.mqueue.\*

Note: if you use the **--ipc=host** option, the above sysctls will not be allowed.

For the network namespace, the following sysctls are allowed:

- Sysctls beginning with net.\*

Note: if you use the **--network=host** option, these sysctls will not be allowed.

#### **--systemd**=**true**|**false**|**always**

Run container in systemd mode. The default is **true**.

The value *always* enforces the systemd mode is enforced without
looking at the executable name. Otherwise, if set to true and the
command you are running inside the container is **systemd**, **/usr/sbin/init**,
**/sbin/init** or **/usr/local/sbin/init**.

Running the container in systemd mode causes the following changes:

* Podman mounts tmpfs file systems on the following directories
  * _/run_
  * _/run/lock_
  * _/tmp_
  * _/sys/fs/cgroup/systemd_
  * _/var/lib/journal_
* Podman sets the default stop signal to **SIGRTMIN+3**.
* Podman sets **container_uuid** environment variable in the container to the
first 32 characters of the container id.

This allows systemd to run in a confined container without any modifications.

Note that on **SELinux** systems, systemd attempts to write to the cgroup
file system. Containers writing to the cgroup file system are denied by default.
The **container_manage_cgroup** boolean must be enabled for this to be allowed on an SELinux separated system.
```
setsebool -P container_manage_cgroup true
```

#### **--timeout**=*seconds*

Maximum time a container is allowed to run before conmon sends it the kill
signal.  By default containers will run until they exit or are stopped by
`podman stop`.

#### **--tls-verify**

Require HTTPS and verify certificates when contacting registries (default: true). If explicitly set to true, then TLS verification will be used. If set to false, then TLS verification will not be used. If not specified, TLS verification will be used unless the target registry is listed as an insecure registry in registries.conf.

#### **--tmpfs**=*fs*

Create a tmpfs mount.

Mount a temporary filesystem (**tmpfs**) mount into a container, for example:

```
$ podman run -d --tmpfs /tmp:rw,size=787448k,mode=1777 my_image
```

This command mounts a **tmpfs** at _/tmp_ within the container. The supported mount
options are the same as the Linux default mount flags. If you do not specify
any options, the systems uses the following options:
**rw,noexec,nosuid,nodev**.

#### **--tty**, **-t**

Allocate a pseudo-TTY. The default is **false**.

When set to **true**, Podman will allocate a pseudo-tty and attach to the standard
input of the container. This can be used, for example, to run a throwaway
interactive shell. The default is **false**.

**NOTE**: The --tty flag prevents redirection of standard output.  It combines STDOUT and STDERR, it can insert control characters, and it can hang pipes. This option should only be used when run interactively in a terminal. When feeding input to Podman, use -i only, not -it.

```
echo "asdf" | podman run --rm -i someimage /bin/cat
```

#### **--tz**=*timezone*

Set timezone in container. This flag takes area-based timezones, GMT time, as well as `local`, which sets the timezone in the container to match the host machine. See `/usr/share/zoneinfo/` for valid timezones.
Remote connections use local containers.conf for defaults

#### **--uidmap**=*container_uid*:*from_uid*:*amount*

Run the container in a new user namespace using the supplied mapping. This
option conflicts with the **--userns** and **--subuidname** options. This
option provides a way to map host UIDs to container UIDs. It can be passed
several times to map different ranges.

The _from_uid_ value is based upon the user running the command, either rootfull or rootless users.
* rootfull user:  *container_uid*:*host_uid*:*amount*
* rootless user: *container_uid*:*intermediate_uid*:*amount*

When **podman run** is called by a privileged user, the option **--uidmap**
works as a direct mapping between host UIDs and container UIDs.

host UID -> container UID

The _amount_ specifies the number of consecutive UIDs that will be mapped.
If for example _amount_ is **4** the mapping would look like:

|   host UID     |    container UID    |
| -              | -                   |
| _from_uid_     | _container_uid_     |
| _from_uid_ + 1 | _container_uid_ + 1 |
| _from_uid_ + 2 | _container_uid_ + 2 |
| _from_uid_ + 3 | _container_uid_ + 3 |

When **podman run** is called by an unprivileged user (i.e. running rootless),
the value _from_uid_ is interpreted as an "intermediate UID". In the rootless
case, host UIDs are not mapped directly to container UIDs. Instead the mapping
happens over two mapping steps:

host UID -> intermediate UID -> container UID

The **--uidmap** option only influences the second mapping step.

The first mapping step is derived by Podman from the contents of the file
_/etc/subuid_ and the UID of the user calling Podman.

First mapping step:

| host UID                                         | intermediate UID |
| -                                                |                - |
| UID for the user starting Podman                 |                0 |
| 1st subordinate UID for the user starting Podman |                1 |
| 2nd subordinate UID for the user starting Podman |                2 |
| 3rd subordinate UID for the user starting Podman |                3 |
| nth subordinate UID for the user starting Podman |                n |

To be able to use intermediate UIDs greater than zero, the user needs to have
subordinate UIDs configured in _/etc/subuid_. See **subuid**(5).

The second mapping step is configured with **--uidmap**.

If for example _amount_ is **5** the second mapping step would look like:

|   intermediate UID   |    container UID    |
| -                    | -                   |
| _from_uid_           | _container_uid_     |
| _from_uid_ + 1       | _container_uid_ + 1 |
| _from_uid_ + 2       | _container_uid_ + 2 |
| _from_uid_ + 3       | _container_uid_ + 3 |
| _from_uid_ + 4       | _container_uid_ + 4 |

When running as rootless, Podman will use all the ranges configured in the _/etc/subuid_ file.

The current user ID is mapped to UID=0 in the rootless user namespace.
Every additional range is added sequentially afterward:

|   host                |rootless user namespace | length              |
| -                     | -                      | -                   |
| $UID                  | 0                      | 1                   |
| 1                     | $FIRST_RANGE_ID        | $FIRST_RANGE_LENGTH |
| 1+$FIRST_RANGE_LENGTH | $SECOND_RANGE_ID       | $SECOND_RANGE_LENGTH|

Even if a user does not have any subordinate UIDs in  _/etc/subuid_,
**--uidmap** could still be used to map the normal UID of the user to a
container UID by running `podman run --uidmap $container_uid:0:1 --user $container_uid ...`.

Note: the **--uidmap** flag cannot be called in conjunction with the **--pod** flag as a uidmap cannot be set on the container level when in a pod.

#### **--ulimit**=*option*

Ulimit options. You can use **host** to copy the current configuration from the host.

#### **--umask**=*umask*

Set the umask inside the container. Defaults to `0022`.
Remote connections use local containers.conf for defaults

#### **--unsetenv**=*env*

Unset default environment variables for the container. Default environment
variables include variables provided natively by Podman, environment variables
configured by the image, and environment variables from containers.conf.

#### **--unsetenv-all**=*true|false*

Unset all default environment variables for the container. Default environment
variables include variables provided natively by Podman, environment variables
configured by the image, and environment variables from containers.conf.

#### **--user**, **-u**=[_user_ | _user_:_group_ | _uid_ | _uid_:_gid_ | _user_:_gid_ | _uid_:_group_ ]

Sets the username or UID used and optionally the groupname or GID for the specified command.

Without this argument, the command will run as the user specified in the container image. Unless overridden by a `USER` command in the Containerfile or by a value passed to this option, this user generally defaults to root.

When a user namespace is not in use, the UID and GID used within the container and on the host will match. When user namespaces are in use, however, the UID and GID in the container may correspond to another UID and GID on the host. In rootless containers, for example, a user namespace is always used, and root in the container will by default correspond to the UID and GID of the user invoking Podman.

#### **--userns**=*mode*

Set the user namespace mode for the container. It defaults to the **PODMAN_USERNS** environment variable. An empty value ("") means user namespaces are disabled unless an explicit mapping is set with the **--uidmap** and **--gidmap** options.

Valid _mode_ values are:

**auto**[:_OPTIONS,..._]: automatically create a unique user namespace.

The `--userns=auto` flag, requires that the user name `containers` and a range of subordinate user ids that the Podman container is allowed to use be specified in the /etc/subuid and /etc/subgid files.

Example: `containers:2147483647:2147483648`.

Podman allocates unique ranges of UIDs and GIDs from the `containers` subordinate user ids. The size of the ranges is based on the number of UIDs required in the image. The number of UIDs and GIDs can be overridden with the `size` option.
The rootless option `--userns=keep-id` uses all the subuids and subgids of the user. Using `--userns=auto` when starting new containers will not work as long as any containers exist that were started with `--userns=keep-id`.

  Valid `auto` options:

  - *gidmapping*=_CONTAINER_GID:HOST_GID:SIZE_: to force a GID mapping to be present in the user namespace.
  - *size*=_SIZE_: to specify an explicit size for the automatic user namespace. e.g. `--userns=auto:size=8192`. If `size` is not specified, `auto` will estimate a size for the user namespace.
  - *uidmapping*=_CONTAINER_UID:HOST_UID:SIZE_: to force a UID mapping to be present in the user namespace.

**container:**_id_: join the user namespace of the specified container.

**host**: run in the user namespace of the caller. The processes running in the container will have the same privileges on the host as any other process launched by the calling user (default).

**keep-id**: creates a user namespace where the current rootless user's UID:GID are mapped to the same values in the container. This option is ignored for containers created by the root user.

**ns:**_namespace_: run the container in the given existing user namespace.

**private**: create a new namespace for the container.

This option is incompatible with **--gidmap**, **--uidmap**, **--subuidname** and **--subgidname**.

#### **--uts**=*mode*

Set the UTS namespace mode for the container. The following values are supported:

- **host**: use the host's UTS namespace inside the container.
- **private**: create a new namespace for the container (default).
- **ns:[path]**: run the container in the given existing UTS namespace.
- **container:[container]**: join the UTS namespace of the specified container.

#### **--variant**=*VARIANT*
Use _VARIANT_ instead of the default architecture variant of the container image. Some images can use multiple variants of the arm architectures, such as arm/v5 and arm/v7.

#### **--volume**, **-v**[=*[[SOURCE-VOLUME|HOST-DIR:]CONTAINER-DIR[:OPTIONS]]*]

Create a bind mount. If you specify _/HOST-DIR_:_/CONTAINER-DIR_, Podman
bind mounts _host-dir_ in the host to _CONTAINER-DIR_ in the Podman
container. Similarly, _SOURCE-VOLUME_:_/CONTAINER-DIR_ will mount the volume
in the host to the container. If no such named volume exists, Podman will
create one. (Note when using the remote client, including Mac and Windows (excluding WSL2) machines, the volumes will be mounted from the remote server, not necessarily the client machine.)

The _options_ is a comma-separated list and can be: <sup>[[1]](#Footnote1)</sup>

* **rw**|**ro**
* **z**|**Z**
* [**r**]**shared**|[**r**]**slave**|[**r**]**private**[**r**]**unbindable**
* [**r**]**bind**
* [**no**]**exec**
* [**no**]**dev**
* [**no**]**suid**
* [**O**]
* [**U**]

The `CONTAINER-DIR` must be an absolute path such as `/src/docs`. The volume
will be mounted into the container at this directory.

Volumes may specify a source as well, as either a directory on the host
or the name of a named volume. If no source is given, the volume will be created as an
anonymously named volume with a randomly generated name, and will be removed when
the container is removed via the `--rm` flag or `podman rm --volumes`.

If a volume source is specified, it must be a path on the host or the name of a
named volume. Host paths are allowed to be absolute or relative; relative paths
are resolved relative to the directory Podman is run in. If the source does not
exist, Podman will return an error. Users must pre-create the source files or
directories.

Any source that does not begin with a `.` or `/` will be treated as the name of
a named volume. If a volume with that name does not exist, it will be created.
Volumes created with names are not anonymous, and they are not removed by the `--rm`
option and the `podman rm --volumes` command.

You can specify multiple **-v** options to mount one or more volumes into a
container.

  `Write Protected Volume Mounts`

You can add **:ro** or **:rw** option to mount a volume in read-only or
read-write mode, respectively. By default, the volumes are mounted read-write.

  `Chowning Volume Mounts`

By default, Podman does not change the owner and group of source volume
directories mounted into containers. If a container is created in a new user
namespace, the UID and GID in the container may correspond to another UID and
GID on the host.

The `:U` suffix tells Podman to use the correct host UID and GID based on the
UID and GID within the container, to change recursively the owner and group of
the source volume.

**Warning** use with caution since this will modify the host filesystem.

  `Labeling Volume Mounts`

Labeling systems like SELinux require that proper labels are placed on volume
content mounted into a container. Without a label, the security system might
prevent the processes running inside the container from using the content. By
default, Podman does not change the labels set by the OS.

To change a label in the container context, you can add either of two suffixes
**:z** or **:Z** to the volume mount. These suffixes tell Podman to relabel file
objects on the shared volumes. The **z** option tells Podman that two containers
share the volume content. As a result, Podman labels the content with a shared
content label. Shared volume labels allow all containers to read/write content.
The **Z** option tells Podman to label the content with a private unshared label.

Note: Do not relabel system files and directories. Relabeling system content
might cause other confined services on your machine to fail.  For these types
of containers we recommend disabling SELinux separation.  The option
`--security-opt label=disable` disables SELinux separation for the container.
For example if a user wanted to volume mount their entire home directory into a
container, they need to disable SELinux separation.

	   $ podman run --security-opt label=disable -v $HOME:/home/user fedora touch /home/user/file

  `Overlay Volume Mounts`

   The `:O` flag tells Podman to mount the directory from the host as a
temporary storage using the `overlay file system`. The container processes
can modify content within the mountpoint which is stored in the
container storage in a separate directory. In overlay terms, the source
directory will be the lower, and the container storage directory will be the
upper. Modifications to the mount point are destroyed when the container
finishes executing, similar to a tmpfs mount point being unmounted.

  For advanced users overlay option also supports custom non-volatile `upperdir` and `workdir`
for the overlay mount. Custom `upperdir` and `workdir` can be fully managed by the users themselves
and `podman` will not remove it on lifecycle completion. Example `:O,upperdir=/some/upper,workdir=/some/work`

  Subsequent executions of the container will see the original source directory
content, any changes from previous container executions no longer exist.

  One use case of the overlay mount is sharing the package cache from the
host into the container to allow speeding up builds.

  Note:

     - The `O` flag conflicts with other options listed above.
Content mounted into the container is labeled with the private label.
       On SELinux systems, labels in the source directory must be readable
by the container label. Usually containers can read/execute `container_share_t`
and can read/write `container_file_t`. If you cannot change the labels on a
source volume, SELinux container separation must be disabled for the container
to work.
     - The source directory mounted into the container with an overlay mount
should not be modified, it can cause unexpected failures. It is recommended
that you do not modify the directory until the container finishes running.

Only the current container can use a private volume.

  `Mounts propagation`

By default bind mounted volumes are `private`. That means any mounts done
inside container will not be visible on host and vice versa. One can change
this behavior by specifying a volume mount propagation property. Making a
volume shared mounts done under that volume inside container will be
visible on host and vice versa. Making a volume **slave** enables only one
way mount propagation and that is mounts done on host under that volume
will be visible inside container but not the other way around. <sup>[[1]](#Footnote1)</sup>

To control mount propagation property of volume one can use [**r**]**shared**,
[**r**]**slave**, [**r**]**private** or [**r**]**unbindable** propagation flag.
Propagation property can be specified only for bind mounted volumes and not for
internal volumes or named volumes. For mount propagation to work source mount
point (mount point where source dir is mounted on) has to have right propagation
properties. For shared volumes, source mount point has to be shared. And for
slave volumes, source mount has to be either shared or slave.
<sup>[[1]](#Footnote1)</sup>

If you want to recursively mount a volume and all of its submounts into a
container, then you can use the **rbind** option. By default the bind option is
used, and submounts of the source directory will not be mounted into the
container.

Mounting the volume with the **nosuid** options means that SUID applications on
the volume will not be able to change their privilege. By default volumes
are mounted with **nosuid**.

Mounting the volume with the **noexec** option means that no executables on the
volume will be able to be executed within the container.

Mounting the volume with the **nodev** option means that no devices on the volume
will be able to be used by processes within the container. By default volumes
are mounted with **nodev**.

If the _host-dir_ is a mount point, then **dev**, **suid**, and **exec** options are
ignored by the kernel.

Use **df $hostdir** to figure out the source mount, and then use
**findmnt -o TARGET,PROPAGATION _source-mount-dir_** to figure out propagation
properties of source mount. If **findmnt**(1) utility is not available, then one
can look at mount entry for source mount point in _/proc/self/mountinfo_. Look
at the "optional fields" and see if any propagation properties are specified.
In there, **shared:N** means the mount is shared, **master:N** means mount
is slave, and if nothing is there, the mount is private. <sup>[[1]](#Footnote1)</sup>

To change propagation properties of a mount point, use **mount**(8) command. For
example, if one wants to bind mount source directory _/foo_, one can do
**mount --bind /foo /foo** and **mount --make-private --make-shared /foo**. This
will convert /foo into a shared mount point. Alternatively, one can directly
change propagation properties of source mount. Say, if _/_ is source mount for
_/foo_, then use **mount --make-shared /** to convert _/_ into a shared mount.

Note: if the user only has access rights via a group, accessing the volume
from inside a rootless container will fail. Use the `--group-add keep-groups`
flag to pass the user's supplementary group access into the container.

#### **--volumes-from**[=*CONTAINER*[:*OPTIONS*]]

Mount volumes from the specified container(s). Used to share volumes between
containers. The *options* is a comma-separated list with the following available elements:

* **rw**|**ro**
* **z**

Mounts already mounted volumes from a source container onto another
container. You must supply the source's container-id or container-name.
To share a volume, use the --volumes-from option when running
the target container. You can share volumes even if the source container
is not running.

By default, Podman mounts the volumes in the same mode (read-write or
read-only) as it is mounted in the source container.
You can change this by adding a `ro` or `rw` _option_.

Labeling systems like SELinux require that proper labels are placed on volume
content mounted into a container. Without a label, the security system might
prevent the processes running inside the container from using the content. By
default, Podman does not change the labels set by the OS.

To change a label in the container context, you can add `z` to the volume mount.
This suffix tells Podman to relabel file objects on the shared volumes. The `z`
option tells Podman that two containers share the volume content. As a result,
Podman labels the content with a shared content label. Shared volume labels allow
all containers to read/write content.

If the location of the volume from the source container overlaps with
data residing on a target container, then the volume hides
that data on the target.

#### **--workdir**, **-w**=*dir*

Working directory inside the container.

The default working directory for running binaries within a container is the root directory (**/**).
The image developer can set a different default with the WORKDIR instruction. The operator
can override the working directory by using the **-w** option.

## Exit Status

The exit code from **podman run** gives information about why the container
failed to run or why it exited. When **podman run** exits with a non-zero code,
the exit codes follow the **chroot**(1) standard, see below:

  **125** The error is with Podman itself

    $ podman run --foo busybox; echo $?
    Error: unknown flag: --foo
    125

  **126** The _contained command_ cannot be invoked

    $ podman run busybox /etc; echo $?
    Error: container_linux.go:346: starting container process caused "exec: \"/etc\": permission denied": OCI runtime error
    126

  **127** The _contained command_ cannot be found

    $ podman run busybox foo; echo $?
    Error: container_linux.go:346: starting container process caused "exec: \"foo\": executable file not found in $PATH": OCI runtime error
    127

  **Exit code** _contained command_ exit code

    $ podman run busybox /bin/sh -c 'exit 3'; echo $?
    3

## EXAMPLES

### Running container in read-only mode

During container image development, containers often need to write to the image
content. Installing packages into _/usr_, for example. In production,
applications seldom need to write to the image.  Container applications write
to volumes if they need to write to file systems at all. Applications can be
made more secure by running them in read-only mode using the **--read-only** switch.
This protects the containers image from modification. Read only containers may
still need to write temporary data. The best way to handle this is to mount
tmpfs directories on _/run_ and _/tmp_.

```
$ podman run --read-only -i -t fedora /bin/bash

$ podman run --read-only --read-only-tmpfs=false --tmpfs /run -i -t fedora /bin/bash
```

### Exposing log messages from the container to the host's log

If you want messages that are logged in your container to show up in the host's
syslog/journal then you should bind mount the _/dev/log_ directory as follows.

```
$ podman run -v /dev/log:/dev/log -i -t fedora /bin/bash
```

From inside the container you can test this by sending a message to the log.

```
(bash)# logger "Hello from my container"
```

Then exit and check the journal.

```
(bash)# exit

$ journalctl -b | grep Hello
```

This should list the message sent to logger.

### Attaching to one or more from STDIN, STDOUT, STDERR

If you do not specify **-a**, Podman will attach everything (stdin, stdout, stderr).
You can specify to which of the three standard streams (stdin, stdout, stderr)
you'd like to connect instead, as in:

```
$ podman run -a stdin -a stdout -i -t fedora /bin/bash
```

### Sharing IPC between containers

Using **shm_server.c** available here: https://www.cs.cf.ac.uk/Dave/C/node27.html

Testing **--ipc=host** mode:

Host shows a shared memory segment with 7 pids attached, happens to be from httpd:

```
$ sudo ipcs -m

------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status
0x01128e25 0          root       600        1000       7
```

Now run a regular container, and it correctly does NOT see the shared memory segment from the host:

```
$ podman run -it shm ipcs -m

------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status
```

Run a container with the new **--ipc=host** option, and it now sees the shared memory segment from the host httpd:

```
$ podman run -it --ipc=host shm ipcs -m

------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status
0x01128e25 0          root       600        1000       7
```
Testing **--ipc=container:**_id_ mode:

Start a container with a program to create a shared memory segment:
```
$ podman run -it shm bash
$ sudo shm/shm_server &
$ sudo ipcs -m

------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status
0x0000162e 0          root       666        27         1
```
Create a 2nd container correctly shows no shared memory segment from 1st container:
```
$ podman run shm ipcs -m

------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status
```

Create a 3rd container using the **--ipc=container:**_id_ option, now it shows the shared memory segment from the first:

```
$ podman run -it --ipc=container:ed735b2264ac shm ipcs -m
$ sudo ipcs -m

------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status
0x0000162e 0          root       666        27         1
```

### Mapping Ports for External Usage

The exposed port of an application can be mapped to a host port using the **-p**
flag. For example, an httpd port 80 can be mapped to the host port 8080 using the
following:

```
$ podman run -p 8080:80 -d -i -t fedora/httpd
```

### Mounting External Volumes

To mount a host directory as a container volume, specify the absolute path to
the directory and the absolute path for the container directory separated by a
colon. If the source is a named volume maintained by Podman, it is recommended to
use its name rather than the path to the volume. Otherwise the volume will be
considered as an orphan and wiped if you execute **podman volume prune**:

```
$ podman run -v /var/db:/data1 -i -t fedora bash

$ podman run -v data:/data2 -i -t fedora bash

$ podman run -v /var/cache/dnf:/var/cache/dnf:O -ti fedora dnf -y update

$ podman run -d -e MYSQL_ROOT_PASSWORD=root --user mysql --userns=keep-id -v ~/data:/var/lib/mysql:z,U mariadb
```

Using **--mount** flags to mount a host directory as a container folder, specify
the absolute path to the directory or the volume name, and the absolute path
within the container directory:

````
$ podman run --mount type=bind,src=/var/db,target=/data1 busybox sh

$ podman run --mount type=bind,src=volume-name,target=/data1 busybox sh
````

When using SELinux, be aware that the host has no knowledge of container SELinux
policy. Therefore, in the above example, if SELinux policy is enforced, the
_/var/db_ directory is not writable to the container. A "Permission Denied"
message will occur and an **avc:** message in the host's syslog.

To work around this, at time of writing this man page, the following command
needs to be run in order for the proper SELinux policy type label to be attached
to the host directory:

```
$ chcon -Rt svirt_sandbox_file_t /var/db
```

Now, writing to the _/data1_ volume in the container will be allowed and the
changes will also be reflected on the host in _/var/db_.

### Using alternative security labeling

You can override the default labeling scheme for each container by specifying
the **--security-opt** flag. For example, you can specify the MCS/MLS level, a
requirement for MLS systems. Specifying the level in the following command
allows you to share the same content between containers.

```
podman run --security-opt label=level:s0:c100,c200 -i -t fedora bash
```

An MLS example might be:

```
$ podman run --security-opt label=level:TopSecret -i -t rhel7 bash
```

To disable the security labeling for this container versus running with the
#### **--permissive** flag, use the following command:

```
$ podman run --security-opt label=disable -i -t fedora bash
```

If you want a tighter security policy on the processes within a container,
you can specify an alternate type for the container. You could run a container
that is only allowed to listen on Apache ports by executing the following
command:

```
$ podman run --security-opt label=type:svirt_apache_t -i -t centos bash
```

Note you would have to write policy defining a **svirt_apache_t** type.

To mask additional specific paths in the container, specify the paths
separated by a colon using the **mask** option with the **--security-opt**
flag.

```
$ podman run --security-opt mask=/foo/bar:/second/path fedora bash
```

To unmask all the paths that are masked by default, set the **unmask** option to
**ALL**. Or to only unmask specific paths, specify the paths as shown above with
the **mask** option.

```
$ podman run --security-opt unmask=ALL fedora bash
```

To unmask all the paths that start with /proc, set the **unmask** option to
**/proc/***.

```
$ podman run --security-opt unmask=/proc/* fedora bash
```

```
$ podman run --security-opt unmask=/foo/bar:/sys/firmware fedora bash
```

### Setting device weight

If you want to set _/dev/sda_ device weight to **200**, you can specify the device
weight by **--blkio-weight-device** flag. Use the following command:

```
$ podman run -it --blkio-weight-device "/dev/sda:200" ubuntu
```

### Using a podman container with input from a pipe

```
$ echo "asdf" | podman run --rm -i --entrypoint /bin/cat someimage
asdf
```

### Setting automatic user namespace separated containers

```
# podman run --userns=auto:size=65536 ubi8-micro cat /proc/self/uid_map
0 2147483647      65536
# podman run --userns=auto:size=65536 ubi8-micro cat /proc/self/uid_map
0 2147549183      65536
```

### Setting Namespaced Kernel Parameters (Sysctls)

The **--sysctl** sets namespaced kernel parameters (sysctls) in the
container. For example, to turn on IP forwarding in the containers
network namespace, run this command:

```
$ podman run --sysctl net.ipv4.ip_forward=1 someimage
```

Note that not all sysctls are namespaced. Podman does not support changing sysctls
inside of a container that also modify the host system. As the kernel
evolves we expect to see more sysctls become namespaced.

See the definition of the **--sysctl** option above for the current list of
supported sysctls.

### Set UID/GID mapping in a new user namespace

Running a container in a new user namespace requires a mapping of
the uids and gids from the host.

```
$ podman run --uidmap 0:30000:7000 --gidmap 0:30000:7000 fedora echo hello
```

### Configuring Storage Options from the command line

Podman allows for the configuration of storage by changing the values
in the _/etc/container/storage.conf_ or by using global options. This
shows how to setup and use fuse-overlayfs for a one time run of busybox
using global options.

```
podman --log-level=debug --storage-driver overlay --storage-opt "overlay.mount_program=/usr/bin/fuse-overlayfs" run busybox /bin/sh
```

### Configure timezone in a container

```
$ podman run --tz=local alpine date
$ podman run --tz=Asia/Shanghai alpine date
$ podman run --tz=US/Eastern alpine date
```

### Adding dependency containers

The first container, container1, is not started initially, but must be running before container2 will start.
The `podman run` command will start the container automatically before starting container2.

```
$ podman create --name container1 -t -i fedora bash
$ podman run --name container2 --requires container1 -t -i fedora bash
```

Multiple containers can be required.

```
$ podman create --name container1 -t -i fedora bash
$ podman create --name container2 -t -i fedora bash
$ podman run --name container3 --requires container1,container2 -t -i fedora bash
```

### Configure keep supplemental groups for access to volume

```
$ podman run -v /var/lib/design:/var/lib/design --group-add keep-groups ubi8
```

### Configure execution domain for containers using personality flag

```
$ podman run --name container1 --personaity=LINUX32 fedora bash
```

### Run a container with external rootfs mounted as an overlay

```
$ podman run --name container1 --rootfs /path/to/rootfs:O bash
```

### Handling Timezones in java applications in a container.

In order to use a timezone other than UTC when running a
Java application within a container, the `TZ` environment variable must be
set within the container. Java applications will ignore the value set with the
`--tz` option.

```
# Example run
podman run -ti --rm  -e TZ=EST mytzimage
lrwxrwxrwx. 1 root root 29 Nov  3 08:51 /etc/localtime -> ../usr/share/zoneinfo/Etc/UTC
Now with default timezone:
Fri Nov 19 18:10:55 EST 2021
Java default sees the following timezone:
2021-11-19T18:10:55.651130-05:00
Forcing UTC:
Fri Nov 19 23:10:55 UTC 2021
```

### Run a container connected to two networks (called net1 and net2) with a static ip

```
$ podman run --network net1:ip=10.89.1.5 --network net2:ip=10.89.10.10 alpine ip addr
```

### Rootless Containers

Podman runs as a non-root user on most systems. This feature requires that a new enough version of **shadow-utils**
be installed. The **shadow-utils** package must include the **newuidmap**(1) and **newgidmap**(1) executables.

In order for users to run rootless, there must be an entry for their username in _/etc/subuid_ and _/etc/subgid_ which lists the UIDs for their user namespace.

Rootless Podman works better if the fuse-overlayfs and slirp4netns packages are installed.
The **fuse-overlayfs** package provides a userspace overlay storage driver, otherwise users need to use
the **vfs** storage driver, which is diskspace expensive and does not perform well. slirp4netns is
required for VPN, without it containers need to be run with the **--network=host** flag.

## ENVIRONMENT

Environment variables within containers can be set using multiple different options,
in the following order of precedence (later entries override earlier entries):

- Container image: Any environment variables specified in the container image.
- **--http-proxy**: By default, several environment variables will be passed in from the host, such as **http_proxy** and **no_proxy**. See **--http-proxy** for details.
- **--env-host**: Host environment of the process executing Podman is added.
- **--env-file**: Any environment variables specified via env-files. If multiple files specified, then they override each other in order of entry.
- **--env**: Any environment variables specified will override previous settings.

Run containers and set the environment ending with a __*__ and a __*****__:

```
$ export ENV1=a
$ podman run --env ENV* alpine printenv ENV1
a

$ podman run --env ENV*****=b alpine printenv ENV*****
b
```

## CONMON

When Podman starts a container it actually executes the conmon program, which
then executes the OCI Runtime.  Conmon is the container monitor.  It is a small
program whose job is to watch the primary process of the container, and if the
container dies, save the exit code.  It also holds open the tty of the
container, so that it can be attached to later. This is what allows Podman to
run in detached mode (backgrounded), so Podman can exit but conmon continues to
run.  Each container has their own instance of conmon. Conmon waits for the
container to exit, gathers and saves the exit code, and then launches a Podman
process to complete the container cleanup, by shutting down the network and
storage.   For more information on conmon, please reference the conmon(8) man
page.

## FILES

**/etc/subuid**

**/etc/subgid**

NOTE: Use the environment variable `TMPDIR` to change the temporary storage location of downloaded container images. Podman defaults to use `/var/tmp`.

## SEE ALSO
**[podman(1)](podman.1.md)**, **[podman-save(1)](podman-save.1.md)**, **[podman-ps(1)](podman-ps.1.md)**, **[podman-attach(1)](podman-attach.1.md)**, **[podman-pod-create(1)](podman-pod-create.1.md)**, **[podman-port(1)](podman-port.1.md)**, **[podman-start(1)](podman-start.1.md)**, **[podman-kill(1)](podman-kill.1.md)**, **[podman-stop(1)](podman-stop.1.md)**, **[podman-generate-systemd(1)](podman-generate-systemd.1.md)**, **[podman-rm(1)](podman-rm.1.md)**, **[subgid(5)](https://www.unix.com/man-page/linux/5/subgid)**, **[subuid(5)](https://www.unix.com/man-page/linux/5/subuid)**, **[containers.conf(5)](https://github.com/containers/common/blob/main/docs/containers.conf.5.md)**, **[systemd.unit(5)](https://www.freedesktop.org/software/systemd/man/systemd.unit.html)**, **[setsebool(8)](https://man7.org/linux/man-pages/man8/setsebool.8.html)**, **[slirp4netns(1)](https://github.com/rootless-containers/slirp4netns/blob/master/slirp4netns.1.md)**, **[fuse-overlayfs(1)](https://github.com/containers/fuse-overlayfs/blob/main/fuse-overlayfs.1.md)**, **proc(5)**, **[conmon(8)](https://github.com/containers/conmon/blob/main/docs/conmon.8.md)**, **personality(2)**

## HISTORY
September 2018, updated by Kunal Kushwaha `<kushwaha_kunal_v7@lab.ntt.co.jp>`

October 2017, converted from Docker documentation to Podman by Dan Walsh for Podman `<dwalsh@redhat.com>`

November 2015, updated by Sally O'Malley `<somalley@redhat.com>`

June 2014, updated by Sven Dowideit `<SvenDowideit@home.org.au>`

April 2014, Originally compiled by William Henry `<whenry@redhat.com>` based on docker.com source material and internal work.

## FOOTNOTES
<a name="Footnote1">1</a>: The Podman project is committed to inclusivity, a core value of open source. The `master` and `slave` mount propagation terminology used here is problematic and divisive, and should be changed. However, these terms are currently used within the Linux kernel and must be used as-is at this time. When the kernel maintainers rectify this usage, Podman will follow suit immediately.
