path: root/docs/source/markdown/podman-create.1.md.in

% podman-create(1)

## NAME
podman\-create - Create a new container

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

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

## DESCRIPTION

Creates a writable container layer over the specified image and prepares it for
running the specified command. The container ID is then printed to STDOUT. This
is similar to **podman run -d** except the container is never started. You can
then use the **podman start** *container* command to start the container at
any point.

The initial status of the container created with **podman create** is 'created'.

Default settings for flags are defined in `containers.conf`. Most settings for
remote connections use the server's 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 create 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 create 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 create 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 create 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 create oci-archive:/tmp/fedora echo hello

## OPTIONS

@@option add-host

@@option annotation.container

@@option arch

#### **--attach**, **-a**=*location*

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 standard
error. It can even pretend to be a TTY (this is what most command line
executables expect) and pass along signals. The **-a** option can be set for
each of stdin, stdout, and stderr.

@@option authfile

@@option blkio-weight

@@option blkio-weight-device

@@option cap-add

@@option cap-drop

@@option cgroup-conf

@@option cgroup-parent

@@option cgroupns

@@option cgroups

@@option chrootdirs

@@option cidfile.write

@@option conmon-pidfile

@@option cpu-period

@@option cpu-quota

@@option cpu-rt-period

@@option cpu-rt-runtime

@@option cpu-shares

@@option cpus.container

@@option cpuset-cpus

@@option cpuset-mems

#### **--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.

@@option device-cgroup-rule

@@option device-read-bps

@@option device-read-iops

@@option device-write-bps

@@option device-write-iops

@@option disable-content-trust

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

Set custom DNS servers. Invalid if using **--dns** and **--network** that is set to 'none' or `container:<name|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.

@@option dns-opt.container

@@option dns-search.container

@@option entrypoint

#### **--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. As a special case, if an environment variable ending in __*__ is specified without a value, Podman will search the host environment for variables starting with the prefix and will add those variables to the container.

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.

@@option env-host

@@option env-merge

@@option expose

@@option gidmap.container

@@option group-add

@@option health-cmd

@@option health-interval

@@option health-retries

@@option health-start-period

@@option health-timeout

#### **--help**

Print usage statement

@@option hostname.container

@@option hostuser

@@option http-proxy

@@option image-volume

@@option init

#### **--init-ctr**=*type*

(Pods only).
When using pods, create an init style container, which is run after the infra container is started
but before regular pod containers are started.  Init containers are useful for running
setup operations for the pod's applications.

Valid values for `init-ctr` type are *always* or *once*.  The *always* value
means the container will run with each and every `pod start`, whereas the *once*
value means the container will only run once when the pod is started and then the container is removed.

Init containers are only run on pod `start`.  Restarting a pod will not execute any init
containers should they be present.  Furthermore, init containers can only be created in a
pod when that pod is not running.

@@option init-path

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

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.


@@option ipc

#### **--label**, **-l**=*label*

Add metadata to a container (e.g., --label com.example.key=value)

@@option label-file

@@option link-local-ip

@@option log-driver

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

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}}"**.

It supports the same keys as **podman inspect --format**.

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

@@option mac-address

@@option memory

@@option memory-reservation

@@option memory-swap

@@option memory-swappiness

@@option mount

#### **--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 rootful 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 rootful 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, they can also be set with `network_cmd_options` in containers.conf:
  - **allow_host_loopback=true|false**: Allow the slirp4netns to reach the host loopback IP (`10.0.2.2`). 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 true. (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.

@@option network-alias

@@option no-healthcheck

@@option no-hosts

This option conflicts with **--add-host**.

@@option oom-kill-disable

@@option oom-score-adj

#### **--os**=*OS*
Override the OS, defaults to hosts, of the image to be pulled. For example, `windows`.
Unless overridden, subsequent lookups of the same image in the local storage will match this OS, regardless of the host.

@@option passwd-entry

@@option personality

@@option pid

@@option pidfile

@@option pids-limit

@@option platform

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

Run container in an existing pod. If you want Podman to make the pod for you, preference the pod name with `new:`.
To make a pod with more granular options, use the `podman pod create` command before creating a container.

@@option pod-id-file.container

#### **--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 not allowed to access any devices.
A “privileged” container is given access to all devices.

When the operator executes a privileged container, Podman enables access
to all devices on the host, turns off graphdriver mount options, as well as
turning off most of the security measures protecting the host from the
container.

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

#### **--publish**, **-p**=*[[ip:][hostPort]:]containerPort[/protocol]*

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.

By default, Podman will publish TCP ports. To publish a UDP port instead, give
`udp` as protocol. To publish both TCP and UDP ports, set `--publish` twice,
with `tcp`, and `udp` as protocols respectively. Rootful containers can also
publish ports using the `sctp` protocol.

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 -P, 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`.

@@option pull

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

Suppress output information when pulling images

@@option read-only

@@option read-only-tmpfs

@@option replace

@@option requires

@@option restart

#### **--rm**

Automatically remove the container when it exits. 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.

@@option sdnotify

@@option seccomp-policy

@@option secret

#### **--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** (`/etc/containers/containers.conf` or `$HOME/.config/containers/containers.conf`) file.

#### **--shm-size**=*size*

Size of `/dev/shm` (format: `<number>[<unit>]`, where unit = b (bytes), k (kibibytes), m (mebibytes), or g (gibibytes))
If you omit the unit, the system uses bytes. If you omit the size entirely, the system uses `64m`.
When size is `0`, there is no limit on the amount of memory used for IPC by the container.

@@option stop-signal

@@option stop-timeout

@@option subgidname

@@option subuidname

#### **--sysctl**=*SYSCTL*

Configure namespaced kernel parameters at runtime

IPC Namespace - current sysctls 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 these sysctls will not be allowed.

Network Namespace - current sysctls allowed:
    Sysctls beginning with net.*

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

@@option systemd

@@option timeout

#### **--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.

@@option tmpfs

#### **--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 **-t** option is incompatible with a redirection of the Podman client
standard input.

@@option tz

@@option uidmap.container

@@option ulimit

@@option umask

@@option unsetenv

@@option unsetenv-all

#### **--user**, **-u**=*user*

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

The following examples are all valid:
--user [user | user:group | uid | uid:gid | user:gid | uid:group ]

Without this argument the command will be run as root in the container.

@@option userns.container

@@option uts.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, ` -v /HOST-DIR:/CONTAINER-DIR`, Podman
bind mounts `/HOST-DIR` in the host to `/CONTAINER-DIR` in the Podman
container. Similarly, `-v SOURCE-VOLUME:/CONTAINER-DIR` will mount the volume
in the host to the container. If no such named volume exists, Podman will
create one. The `OPTIONS` are a comma-separated list and can be: <sup>[[1]](#Footnote1)</sup>  (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:

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

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` suffix to a volume to mount it read-only or
read-write mode, respectively. By default, the volumes are mounted read-write.
See examples.

  `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.
Only the current container can use a private volume.

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 containers used in the build.
For example if a user wanted to volume mount their entire home directory into a
container, they need to disable SELinux separation.

	   $ podman create --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.

  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.

  `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 a volume one can use the [**r**]**shared**,
[**r**]**slave**, [**r**]**private** or the [**r**]**unbindable** propagation flag.
For mount propagation to work the source mount point (the mount point where source dir
is mounted on) has to have the right propagation properties. For shared volumes, the
source mount point has to be shared. And for slave volumes, the source mount point
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 `<source-dir>` is a mount point, then "dev", "suid", and "exec" options are
ignored by the kernel.

Use `df <source-dir>` 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` utility is not available, then one
can look at mount entry for source mount point in `/proc/self/mountinfo`. Look
at `optional fields` and see if any propagation properties are specified.
`shared:X` means mount is `shared`, `master:X` means mount is `slave` and if
nothing is there that means mount is `private`. <sup>[[1]](#Footnote1)</sup>

To change propagation properties of a mount point use `mount` 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 `/` 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.

@@option workdir

## EXAMPLES

### Create a container using a local image

```
$ podman create alpine ls
```

### Create a container using a local image and annotate it

```
$ podman create --annotation HELLO=WORLD alpine ls
```

### Create a container using a local image, allocating a pseudo-TTY, keeping stdin open and name it myctr

```
  podman create -t -i --name myctr alpine ls
```

### 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 create --uidmap 0:30000:7000 --gidmap 0:30000:7000 fedora echo hello
```

### Setting automatic user namespace separated containers

```
# podman create --userns=auto:size=65536 ubi8-init
```

### Configure timezone in a container

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

### Adding dependency containers

Podman will make sure the first container, container1, is running before the second container (container2) is started.

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

Multiple containers can be required.

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

### Configure keep supplemental groups for access to volume

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

### Configure execution domain for containers using personality flag

```
$ podman create --name container1 --personality=LINUX32 fedora bash
```

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

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

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

```
$ podman create --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 and newgidmap 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:  This section describes the precedence.

Precedence order (later entries override earlier entries):

- **--env-host** : Host environment of the process executing Podman is added.
- **--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.
- Container image : Any environment variables specified in the container image.
- **--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.

Create containers and set the environment ending with a __*__.
The trailing __*__ glob functionality is only active when no value is specified:

```
$ export ENV1=a
$ podman create --name ctr1 --env 'ENV*' alpine env
$ podman start --attach ctr1 | grep ENV
ENV1=a
$ podman create --name ctr2 --env 'ENV*=b' alpine env
$ podman start --attach ctr2 | grep ENV
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
October 2017, converted from Docker documentation to Podman by Dan Walsh for Podman `<dwalsh@redhat.com>`

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

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

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

## 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.