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Diffstat (limited to 'docs/source/markdown/podman-run.1.md')
| -rw-r--r-- | docs/source/markdown/podman-run.1.md | 864 |
1 files changed, 422 insertions, 442 deletions
diff --git a/docs/source/markdown/podman-run.1.md b/docs/source/markdown/podman-run.1.md index 3befc74c8..f391307b3 100644 --- a/docs/source/markdown/podman-run.1.md +++ b/docs/source/markdown/podman-run.1.md @@ -11,112 +11,112 @@ podman\-run - Run a command in a new container ## 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 +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 +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. +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. +_/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, an empty file is created in +servers in the created _resolv.conf_). Additionally, an empty file is created in each container to indicate to programs they are running in a container. This file -is located at `/run/.containerenv`. +is located at _/run/.containerenv_. -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. +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. ## OPTIONS -**--add-host**=*host:ip* +**--add-host**=_host_:_ip_ -Add a custom host-to-IP mapping (host:ip) +Add a line to container's _/etc/hosts_ for custom host-to-IP mapping. +This option can be set multiple times. -Add a line to /etc/hosts. The format is hostname:ip. The **--add-host** -option can be set multiple times. +**--annotation**=_key_=_value_ -**--annotation**=*key=value* +Add an annotation to the container. +This option can be set multiple times. -Add an annotation to the container. The format is key=value. -The **--annotation** option can be set multiple times. - -**--attach**, **-a**=*stdio* +**--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 standard +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. +each of **stdin**, **stdout**, and **stderr**. **--authfile**[=*path*] -Path of the authentication file. Default is ${XDG\_RUNTIME\_DIR}/containers/auth.json (Not available for remote commands) +Path to the authentication file. Default is *${XDG_RUNTIME_DIR}/containers/auth.json*. (Not available for remote commands) -Note: You can also override the default path of the authentication file by setting the REGISTRY\_AUTH\_FILE -environment variable. `export REGISTRY_AUTH_FILE=path` +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 weight (relative weight) accepts a weight value between 10 and 1000. +Block IO relative weight. The _weight_ is a value between **10** and **1000**. -**--blkio-weight-device**=*DEVICE_NAME:WEIGHT* +**--blkio-weight-device**=*device*:*weight* -Block IO weight (relative device weight, format: `DEVICE_NAME:WEIGHT`). +Block IO relative device weight. **--cap-add**=*capability* -Add Linux capabilities +Add Linux capabilities. **--cap-drop**=*capability* -Drop Linux capabilities +Drop Linux capabilities. **--cgroupns**=*mode* Set the cgroup namespace mode for the container. - **host**: use the host's cgroup namespace inside the container. - **container:<NAME|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**. +- **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**=*mode* +**--cgroups**=**enabled**|**disabled**|**no-conmon** Determines whether the container will create CGroups. -Valid values are *enabled*, *disabled*, *no-conmon*, which the default being *enabled*. -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. -**--cgroup-parent**=*cgroup* +Default is **enabled**. 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. + +**--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. **--cidfile**=*file* -Write the container ID to the file +Write the container ID to *file*. **--conmon-pidfile**=*file* -Write the pid of the `conmon` process to a file. `conmon` runs in a separate process than Podman, so this is necessary when using systemd to restart Podman containers. +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. **--cpu-period**=*limit* -Limit the CPU CFS (Completely Fair Scheduler) period - -Limit the container's CPU usage. This flag tell the kernel to restrict the container's CPU usage to the period you specify. +Limit the container's CPU usage by setting CPU CFS (Completely Fair Scheduler) period. **--cpu-quota**=*limit* -Limit the CPU CFS (Completely Fair Scheduler) quota +Limit the CPU CFS (Completely Fair Scheduler) quota. Limit the container's CPU usage. By default, containers run with the full CPU resource. This flag tell the kernel to restrict the container's CPU usage @@ -124,13 +124,13 @@ to the quota you specify. **--cpu-rt-period**=*microseconds* -Limit the CPU real-time period in 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. **--cpu-rt-runtime**=*microseconds* -Limit the CPU real-time runtime in 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. @@ -139,14 +139,11 @@ The sum of all runtimes across containers cannot exceed the amount allotted to t **--cpu-shares**=*shares* -CPU shares (relative weight) +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 weighting of all other running containers. - -To modify the proportion from the default of 1024, use the **--cpu-shares** -flag to set the weighting to 2 or higher. +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 @@ -165,14 +162,15 @@ 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 **-c=512** running one process, and another container -**{C1}** with **-c=1024** running two processes, this can result in the following +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 +| 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* @@ -180,80 +178,90 @@ Number of CPUs. The default is *0.0* which means no limit. **--cpuset-cpus**=*number* -CPUs in which to allow execution (0-3, 0,1) +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 (0-3, 0,1). Only effective on NUMA systems. +Memory nodes (MEMs) in which to allow execution. Only effective on NUMA systems. -If you have four memory nodes on your system (0-3), use `--cpuset-mems=0,1` -then processes in your container will only use memory from the first -two memory nodes. +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**=*true|false* +**--detach**, **-d**=**true**|**false** -Detached mode: run the container in the background and print the new container ID. The default is *false*. +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 **libpod.conf** file: see **libpod.conf(5)** for more information. +running) using a configurable key sequence. + +**--detach-keys**=_sequence_ -**--detach-keys**=*sequence* +Specify the key sequence for detaching a container; _sequence_ is a comma-delimited set +in which each item can be a single character from the [a-Z] range, +or **ctrl**-_value_, where _value_ is one of: **a-z** or **@^[,_**. -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 disable this feature. The default is *ctrl-p,ctrl-q*. +This option can also be set in **libpod.conf**(5) file. -**--device**=*device* +Specifying "" will disable this feature. The default is **ctrl-p,ctrl-q**. -Add a host device to the container. The format is `<device-on-host>[:<device-on-container>][:<permissions>]` (e.g. --device=/dev/sdc:/dev/xvdc:rwm) +**--device**=_host-device_[**:**_container-device_][**:**_permissions_] -Note: if the user only has access rights via a group then accessing the device -from inside a rootless container will fail. The `crun` runtime offers a -workaround for this by adding the option `--annotation run.oci.keep_original_groups=1`. +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). -**--device-read-bps**=*path* +Example: **--device=/dev/sdc:/dev/xvdc:rwm**. -Limit read rate (bytes per second) from a device (e.g. --device-read-bps=/dev/sda:1mb) +Note: if the user only has access rights via a group, accessing the device +from inside a rootless container will fail. The **crun**(1) runtime offers a +workaround for this by adding the option **--annotation run.oci.keep_original_groups=1**. -**--device-read-iops**=*path* +**--device-read-bps**=_path_:_rate_ -Limit read rate (IO per second) from a device (e.g. --device-read-iops=/dev/sda:1000) +Limit read rate (in bytes per second) from a device (e.g. **--device-read-bps=/dev/sda:1mb**). -**--device-write-bps**=*path* +**--device-read-iops**=_path_:_rate_ -Limit write rate (bytes per second) to a device (e.g. --device-write-bps=/dev/sda:1mb) +Limit read rate (in IO operations per second) from a device (e.g. **--device-read-iops=/dev/sda:1000**). -**--device-write-iops**=*path* +**--device-write-bps**=_path_:_rate_ -Limit write rate (IO per second) to a device (e.g. --device-write-iops=/dev/sda:1000) +Limit write rate (in bytes per second) to a device (e.g. **--device-write-bps=/dev/sda:1mb**). -**--dns**=*dns* +**--device-write-iops**=_path_:_rate_ -Set custom DNS servers. Invalid if using **--dns** with **--network** that is set to 'none' or 'container:<name|id>'. +Limit write rate (in IO operations per second) to a device (e.g. **--device-write-iops=/dev/sda:1000**). + +**--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 +host DNS configuration is invalid for the container (e.g., **127.0.0.1**). When this is the case the **--dns** flags 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. +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-option**=*option* -Set custom DNS options. Invalid if using **--dns-option** with **--network** that is set to 'none' or 'container:<name|id>'. +Set custom DNS options. Invalid if using **--dns-option** 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:<name|id>'. (Use --dns-search=. if you don't wish to set the 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 +Overwrite the default ENTRYPOINT of the image. This option allows you to overwrite the default entrypoint of the image. @@ -271,13 +279,13 @@ You need to specify multi option commands in the form of a json string. **--env**, **-e**=*env* -Set environment variables +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-host**=*true|false* +**--env-host**=**true**|**false** Use host environment inside of the container. See **Environment** note below for precedence. @@ -287,14 +295,14 @@ Read in a line delimited file of environment variables. See **Environment** note **--expose**=*port* -Expose a port, or a range of ports (e.g. --expose=3300-3310) to set up port redirection +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* +**--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` +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**. **--group-add**=*group* @@ -304,28 +312,28 @@ Add additional groups to run as 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. +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`. +as an argument to **/bin/sh -c**. **--health-interval**=*interval* -Set an interval for the healthchecks (a value of `disable` results in no automatic timer setup) (default "30s") +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`. +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` +**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`. +value can be expressed in a time format such as **1m22s**. The default value is **30s**. **--help** @@ -337,37 +345,30 @@ Container host name Sets the container host name that is available inside the container. -**--http-proxy**=*true|false* +**--http-proxy**=**true**|**false** By default proxy environment variables are passed into the container if set -for the Podman process. This can be disabled by setting the `--http-proxy` -option to `false`. The environment variables passed in include `http_proxy`, -`https_proxy`, `ftp_proxy`, `no_proxy`, and also the upper case versions of +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 +container include passing the values with the **--env** flag, or hard coding the proxy environment at container build time.) -For example, to disable passing these environment variables from host to -container: - -`--http-proxy=false` +Defaults to **true**. -Defaults to `true` +**--image-volume**, **builtin-volume**=**bind**|**tmpfs**|**ignore** -**--image-volume**, **builtin-volume**=*bind|tmpfs|ignore* +Tells Podman how to handle the builtin image volumes. Default is **bind**. -Tells Podman how to handle the builtin image volumes. - -The options are: `bind`, `tmpfs`, or `ignore` (default `bind`) - -- `bind`: A directory is created inside the container state directory and bind mounted into +- **bind**: A directory is created inside the container state directory and bind mounted into the container for the volumes. -- `tmpfs`: The volume is mounted onto the container as a tmpfs, which allows the users to create +- **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. +- **ignore**: All volumes are just ignored and no action is taken. **--init** @@ -377,74 +378,70 @@ Run an init inside the container that forwards signals and reaps processes. Path to the container-init binary. -**--interactive**, **-i**=*true|false* +**--interactive**, **-i**=**true**|**false** -When set to true, keep stdin open even if not attached. The default is *false*. +When set to **true**, keep stdin open even if not attached. The default is **false**. **--ip6**=*ip* -Not implemented +Not implemented. **--ip**=*ip* -Specify a static IP address for the container, for example '10.88.64.128'. -Can only be used if no additional CNI networks to join were specified via '--network=<network-name>', and if the container is not joining another container's network namespace via '--network=container:<name|id>'. -The address must be within the default CNI network's pool (default 10.88.0.0/16). +Specify a static IP address for the container, for example **10.88.64.128**. +Can only be used if no additional CNI networks to join were specified via **--network=**_network-name_, +and if the container is not joining another container's network namespace via **--network=container:**_id_. +The address must be within the default CNI network's pool (default **10.88.0.0/16**). -**--ipc**=*ipc* +**--ipc**=*mode* -Default is to create a private IPC namespace (POSIX SysV IPC) for the container +Set the IPC namespace mode for a container. The default is to create +a private IPC namespace. -- `container:<name|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. +- **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. -**--kernel-memory**=*number[unit]* +**--kernel-memory**=_number_[_unit_] -Kernel memory limit (format: `<number>[<unit>]`, where unit = b (bytes), k (kilobytes), m (megabytes), or g (gigabytes)) +Kernel memory limit. A _unit_ can be **b** (bytes), **k** (kilobytes), **m** (megabytes), or **g** (gigabytes). Constrains the kernel memory available to a container. If a limit of 0 -is specified (not using `--kernel-memory`), the container's kernel memory +is specified (not using *--kernel-memory*), the container's kernel memory is not limited. If you specify a limit, it may be rounded up to a multiple of the operating system's page size and the value can be very large, millions of trillions. -**--label**, **-l**=*label* +**--label**, **-l**=*key*=*value* -Add metadata to a container (e.g., --label com.example.key=value) +Add metadata to a container. **--label-file**=*file* -Read in a line delimited file of labels +Read in a line-delimited file of labels. **--link-local-ip**=*ip* -Not implemented - -**--log-driver**="*k8s-file*" +Not implemented. -Logging driver for the container. Currently available options are *k8s-file* and *journald*, with *json-file* aliased to *k8s-file* for scripting compatibility. +**--log-driver**="*driver*" -**--log-opt**=*path* +Logging driver for the container. Currently available options are **k8s-file** and **journald**, with **json-file** aliased to **k8s-file** for scripting compatibility. -Set custom logging configuration. Presently supports the `tag` option -which specified a custom log tag for the container. For example: +**--log-opt**=*name*=*value* -`--log-opt path=/var/log/container/mycontainer.json` +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**); +- **tag**: specify a custom log tag for the container (e.g. +**--log-opt tag="{{.ImageName}}"**. It supports the same +keys as **podman inspect --format**. -**--log-opt**=*tag* - -Specify a custom log tag for the container. For example: - -`--log-opt tag="{{.ImageName}}"` - -It supports the same keys as `podman inspect --format`. - -It is currently supported only by the journald log driver. +This option is currently supported only by the **journald** log driver. **--mac-address**=*address* -Container MAC address (e.g. `92:d0:c6:0a:29:33`) +Container MAC address (e.g. **92:d0:c6:0a:29:33**). 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 @@ -452,9 +449,9 @@ according to RFC4862. Not currently supported -**--memory**, **-m**=*limit* +**--memory**, **-m**=_number_[_unit_] -Memory limit (format: <number>[<unit>], where unit = b (bytes), k (kilobytes), m (megabytes), or g (gigabytes)) +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 @@ -462,9 +459,9 @@ 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**=*limit* +**--memory-reservation**=_number_[_unit_] -Memory soft limit (format: <number>[<unit>], where unit = b (bytes), k (kilobytes), m (megabytes), or g (gigabytes)) +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 @@ -472,26 +469,27 @@ reservation. So you should always set the value below **--memory**, otherwise th hard limit will take precedence. By default, memory reservation will be the same as memory limit. -**--memory-swap**=*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). -A limit value equal to memory plus swap. Must be used with the **-m** -(**--memory**) flag. The swap `LIMIT` should always be larger than **-m** -(**--memory**) value. By default, the swap `LIMIT` will be set to double -the value of --memory. +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**. -The format of `LIMIT` is `<number>[<unit>]`. Unit can be `b` (bytes), -`k` (kilobytes), `m` (megabytes), or `g` (gigabytes). If you don't specify a -unit, `b` is used. Set LIMIT to `-1` to enable unlimited swap. +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. +Tune a container's memory swappiness behavior. Accepts an integer between *0* and *100*. **--mount**=*type=TYPE,TYPE-SPECIFIC-OPTION[,...]* Attach a filesystem mount to the container -Current supported mount TYPES are `bind`, `volume`, and `tmpfs`. +Current supported mount TYPEs are **bind**, **volume**, and **tmpfs**. e.g. @@ -531,158 +529,154 @@ Current supported mount TYPES are `bind`, `volume`, and `tmpfs`. **--name**=*name* -Assign a name to the container +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 +- 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**, **--net**=*node* +**--network**, **--net**=*mode* -Set the Network mode for the container. Invalid if using **--dns**, **--dns-option**, or **--dns-search** with **--network** that is set to 'none' or 'container:<name|id>'. +Set the network mode for the container. Invalid if using **--dns**, **--dns-option**, or **--dns-search** with **--network** that is set to **none** or **container:**_id_. -Valid values are: +Valid _mode_ values are: -- `bridge`: create a network stack on the default bridge -- `none`: no networking -- `container:<name|id>`: reuse another container's network stack -- `host`: use the Podman host network stack. Note: the host mode gives the container full access to local system services such as D-bus and is therefore considered insecure. -- `<network-name>|<network-id>`: connect to a user-defined network, multiple networks should be comma separated -- `ns:<path>`: path to a network namespace to join -- `slirp4netns`: use slirp4netns to create a user network stack. This is the default for rootless containers +- **bridge**: create a network stack on the default bridge; +- **none**: no networking; +- **container:**_id_: reuse another container's network stack; +- **host**: use the Podman host network stack. Note: the host mode gives the container full access to local system services such as D-bus and is therefore considered insecure; +- _network-id_: connect to a user-defined network, multiple networks should be comma separated; +- **ns:**_path_: path to a network namespace to join; +- **slirp4netns**: use **slirp4netns**(1) to create a user network stack. This is the default for rootless containers. **--network-alias**=*alias* -Not implemented +Not implemented. -**--no-hosts**=*true|false* +**--no-hosts**=**true**|**false** -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/host** will be preserved unmodified. +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**=*true|false* +**--oom-kill-disable**=**true**|**false** Whether to disable OOM Killer for the container or not. **--oom-score-adj**=*num* -Tune the host's OOM preferences for containers (accepts -1000 to 1000) - -**--pid**=*pid* +Tune the host's OOM preferences for containers (accepts values from **-1000** to **1000**). -Set the PID mode for the container +**--pid**=*mode* -Default is to create a private PID namespace for the container +Set the PID namespace mode for the container. +The efault is to create a private PID namespace for the container. -- `container:<name|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. -- `ns`: join the specified PID namespace +- **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; +- **ns:**_path_: join the specified PID namespace. **--pids-limit**=*limit* -Tune the container's pids limit. Set `0` to have unlimited pids for the container. (default "4096" on systems that support PIDS cgroups). +Tune the container's pids limit. Set to **0** to have unlimited pids for the container. The default is **4096** on systems that support "pids" cgroup controller. **--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. +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. -**--privileged**=*true|false* +**--privileged**=**true**|**false** -Give extended privileges to this container. The default is *false*. +Give extended privileges to this container. The default is **false**. -By default, Podman containers are “unprivileged” (=false) and cannot, for +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 +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**=*port* - -Publish a container's port, or range of ports, to the host +**--publish**, **-p**=_ip_:_hostPort_:_containerPort_ | _ip_::_containerPort_ | _hostPort_:_containerPort_ | _containerPort_ -Format: `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. -(e.g., `podman run -p 1234-1236:1222-1224 --name thisWorks -t busybox` -but not `podman run -p 1230-1236:1230-1240 --name RangeContainerPortsBiggerThanRangeHostPorts -t busybox`) -With ip: `podman run -p 127.0.0.1:$HOSTPORT:$CONTAINERPORT --name CONTAINER -t someimage` +Use **podman port** to see the actual mapping: **podman port $CONTAINER $CONTAINERPORT**. -Use `podman port` to see the actual mapping: `podman port CONTAINER $CONTAINERPORT` +**--publish-all**, **-P**=**true**|**false** -**--publish-all**, **-P**=*true|false* +Publish all exposed ports to random ports on the host interfaces. The default is **false**. -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 +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`. +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**=*missing* +**--pull**=**always**|**missing**|**never** -Pull image before running ("always"|"missing"|"never") (default "missing"). - 'missing': default value, 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. +Pull image before running. The default is **missing**. -Defaults to *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**=*true|false* +**--read-only**=**true**|**false** 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 +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**=*true|false* +**--read-only-tmpfs**=**true**|**false** -If container is running in --read-only mode, then mount a read-write tmpfs on /run, /tmp, and /var/tmp. The default is *true* +If container is running in **--read-only** mode, then mount a read-write tmpfs on _/run_, _/tmp_, and _/var/tmp_. The default is **true**. **--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. +Restart policy will not take effect if a container is stopped via the **podman kill** or **podman stop** commands. -Valid values are: +Valid _policy_ values are: -- `no` : Do not restart containers on exit -- `on-failure[:max_retries]` : Restart containers when they exit with a non-0 exit code, retrying indefinitely or until the optional max_retries count is hit -- `always` : Restart containers when they exit, regardless of status, retrying indefinitely +- **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. 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 file, or create an init script for whichever init system is in use. -To generate systemd unit files, please see *podman generate systemd* +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**=*true|false* +**--rm**=**true**|**false** -Automatically remove the container when it exits. The default is *false*. +Automatically remove the container when it exits. The default is **false**. Note that the container will not be removed when it could not be created or started successfully. This allows the user to inspect the container after @@ -695,8 +689,8 @@ If specified, the first argument refers to an exploded container on the file sys This is useful to run a container without requiring any image management, the rootfs of the container is assumed to be managed externally. -Note: On `SELinux` systems, the rootfs needs the correct label, which is by default -`unconfined_u:object_r:container_file_t`. +Note: On **SELinux** systems, the rootfs needs the correct label, which is by default +**unconfined_u:object_r:container_file_t**. **--seccomp-policy**=*policy* @@ -708,58 +702,55 @@ Note that this feature is experimental and may change in the future. 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 +- **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 +- **no-new-privileges**: Disable container processes from gaining additional privileges +- **seccomp=unconfined**: Turn off seccomp confinement for the container +- **seccomp**=_profile.json_: Whitelisted syscalls seccomp JSON file to be used as a seccomp filter -- `no-new-privileges` : Disable container processes from gaining additional privileges +Note: Labeling can be disabled for all containers by setting **label=false** in the **libpod.conf**(5) file. -- `seccomp=unconfined` : Turn off seccomp confinement for the container -- `seccomp=profile.json` : White listed syscalls seccomp Json file to be used as a seccomp filter +**--shm-size**=_number_[_unit_] -Note: Labeling can be disabled for all containers by setting label=false in the **libpod.conf** (`/etc/containers/libpod.conf`) file. +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. -**--shm-size**=*size* +**--sig-proxy**=**true**|**false** -Size of `/dev/shm` (format: <number>[<unit>], where unit = 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 system uses `64m`. -When size is `0`, there is no limit on the amount of memory used for IPC by the container. +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**. -**--sig-proxy**=*true|false* +**--stop-signal**=*signal* -Proxy signals sent to the `podman run` command to the container process. SIGCHLD, SIGSTOP, and SIGKILL are not proxied. The default is *true*. - -**--stop-signal**=*SIGTERM* - -Signal to stop a container. Default is SIGTERM. +Signal to stop a container. Default is **SIGTERM**. **--stop-timeout**=*seconds* -Timeout (in seconds) to stop a container. Default is 10. +Timeout to stop a container. Default is **10**. **--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`. +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`. +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**=SYSCTL +**--sysctl**=_name_=_value_ -Configure namespaced kernel parameters at runtime +Configure namespaced kernel parameters at runtime. -IPC Namespace - current sysctls allowed: +For the IPC namespace, the following sysctls are allowed: - kernel.msgmax - kernel.msgmnb @@ -769,147 +760,148 @@ IPC Namespace - current sysctls allowed: - kernel.shmmax - kernel.shmmni - kernel.shm_rmid_forced -- Sysctls beginning with fs.mqueue.* +- Sysctls beginning with fs.mqueue.\* + +Note: if you use the **--ipc=host** option, the above sysctls will not be allowed. -Note: if you use the `--ipc=host` option these sysctls will not be allowed. +For the network namespace, the following ysctls areallowed: -Network Namespace - current sysctls allowed: -- Sysctls beginning with net.* +- Sysctls beginning with net.\* -Note: if you use the `--network=host` option these sysctls will not be allowed. +Note: if you use the **--network=host** option, these sysctls will not be allowed. -**--systemd**=*true|false|always* +**--systemd**=**true**|**false**|**always** -Run container in systemd mode. The default is *true*. +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 -or /sbin/init. +looking at the executable name. Otherwise, if set to **true** and the +command you are running inside the container is systemd, _/usr/sbin/init_ +or _/sbin/init_. If the command you are running inside of the container is systemd Podman will setup tmpfs mount points in the following directories: -/run, /run/lock, /tmp, /sys/fs/cgroup/systemd, /var/lib/journal +- _/run_ +- _/run/lock_ +- _/tmp_ +- _/sys/fs/cgroup/systemd_ +- _/var/lib/journal_ -It will also set the default stop signal to SIGRTMIN+3. +It will also set the default stop signal to **SIGRTMIN+3**. This allows systemd to run in a confined container without any modifications. -Note: On `SELinux` systems, systemd attempts to write to the cgroup +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` +The **container_manage_cgroup** boolean must be enabled for this to be allowed on an SELinux separated system. +``` +setsebool -P container_manage_cgroup true +``` **--tmpfs**=*fs* -Create a tmpfs mount +Create a tmpfs mount. -Mount a temporary filesystem (`tmpfs`) mount into a container, for example: +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 +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`. +**rw,noexec,nosuid,nodev**. -**--tty**, **-t**=*true|false* +**--tty**, **-t**=**true**|**false** -Allocate a pseudo-TTY. The default is *false*. +Allocate a pseudo-TTY. The default is **false**. -When set to true Podman will allocate a pseudo-tty and attach to the standard +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. +interactive shell. The default is **false**. **NOTE**: The **-t** option is incompatible with a redirection of the Podman client standard input. -**--uidmap**=*container_uid:host_uid:amount* +**--uidmap**=*container_uid*:*host_uid*:*amount* -Run the container in a new user namespace using the supplied mapping. This option conflicts with the --userns and --subuidname 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 uids 0-1999 in the container to the uids 30000-31999 on the host. `--uidmap=0:30000:2000` +Run the container in a new user namespace using the supplied mapping. This option conflicts +with the **--userns** and **--subuidname** 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). -**--ulimit**=*option* +The following example maps uids 0-1999 in the container to the uids 30000-31999 on the host: **--uidmap=0:30000:2000**. -Ulimit options +**--ulimit**=*option* -You can pass `host` to copy the current configuration from the host. +Ulimit options. You can use **host** to copy the current configuration from the host. -**--user**, **-u**=*user* +**--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. -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. -**--userns**=host -**--userns**=keep-id -**--userns**=container:container -**--userns**=ns:my_namespace +**--userns**=**host**|**keep-id**|**container:**_id_|**ns:**_namespace_ Set the user namespace mode for the container. It defaults to the **PODMAN_USERNS** environment variable. An empty value means user namespaces are disabled. -- `host`: run in the user namespace of the caller. This is the default if no user namespace options are set. The processes running in the container will have the same privileges on the host as any other process launched by the calling user. -- `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`: run the container in the given existing user namespace. -- `container`: join the user namespace of the specified container. +- **host**: run in the user namespace of the caller. This is the default if no user namespace options are set. The processes running in the container will have the same privileges on the host as any other process launched by the calling user. +- **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**: run the container in the given existing user namespace. +- **container**: join the user namespace of the specified container. -This option is incompatible with --gidmap, --uidmap, --subuid and --subgid +This option is incompatible with **--gidmap**, **--uidmap**, **--subuid** and **--subgid**. -**--uts**=*host* +**--uts**=*mode* -Set the UTS mode for the container +Set the UTS namespace mode for the container. The following values are supported: -- `host`: use the host's UTS namespace inside the container. -- `ns`: specify the user namespace to use. +- **host**: use the host's UTS namespace inside the container. +- **ns**: use own UTS namespace. **NOTE**: the host mode gives the container access to changing the host's hostname and is therefore considered insecure. -**--volume**, **-v**[=*[[SOURCE-VOLUME|HOST-DIR:]CONTAINER-DIR[:OPTIONS]]*] +**--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 VOLUME-NAME:/CONTAINER-DIR` will mount the volume +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. - The `OPTIONS` are a comma delimited list and can be: +The _options_ is a comma delimited list and can be: -* [`rw`|`ro`] -* [`z`|`Z`] -* [`[r]shared`|`[r]slave`|`[r]private`] -* [`[r]bind`] -* [`noexec`|`exec`] -* [`nodev`|`dev`] -* [`nosuid`|`suid`] +* **rw**|**ro** +* **z**|**Z** +* [**r**]**shared**|[**r**]**slave**|[**r**]**private** +* [**r**]**bind** +* [**no**]**exec** +* [**no**]**dev** +* [**no**]**suid** -The `CONTAINER-DIR` must be an absolute path such as `/src/docs`. The volume -will be mounted into the container at this directory. +The _container-dir_ must be an absolute path. 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 anonymous named volume with a randomly generated name, and will be removed when -the container is removed via the `--rm` flag or `podman rm --volumes`. +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. Any source that does -not begin with a `.` or `/` it will be treated as the name of a named volume. +not begin with a **.** or **/** it 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 are not removed by `--rm` and -`podman rm --volumes`. +with names are not anonymous and are not removed by **--rm** and +**podman rm --volumes**. You can specify multiple **-v** options to mount one or more volumes into a container. -You can add `:ro` or `:rw` suffix to a volume to mount it read-only or +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. -See examples. Labeling systems like SELinux require that proper labels are placed on volume content mounted into a container. Without a label, the security system might @@ -917,89 +909,84 @@ 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 +**: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. +The **Z** option tells Podman to label the content with a private unshared label. Only the current container can use a private volume. -By default bind mounted volumes are `private`. That means any mounts done +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 +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. -To control mount propagation property of volume one can use `:[r]shared`, -`:[r]slave` or `:[r]private` propagation flag. Propagation property can +To control mount propagation property of volume one can use [**r**]**shared**, +[**r**]**slave** or [**r**]**private** 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. -If you want to recursively mount a volume and all of it's submounts into a -container, then you can use the `rbind` option. By default the bind option is +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 +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`. +are mounted with **nosuid**. -Mounting the volume with the noexec option means that no executables on the +Mounting the volume with the **noexec** option means that no executables on the volume will be able to executed within the container. -Mounting the volume with the nodev option means that no devices on the volume +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`. +are mounted with **nodev**. -If the <source-dir> is a mount point, then "dev", "suid", and "exec" options are +If the _host-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`. +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. -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. +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. -**--volumes-from**[=*CONTAINER*[:*OPTIONS*]] +**--volumes-from**[=*container-id*[:*options*]] -Mount volumes from the specified container(s). -*OPTIONS* is a comma delimited list with the following available elements: +Mount volumes from the specified container(s). Used to share volumes between +containers. The *options* is a comma delimited list with the following available elements: -* [rw|ro] -* z +* **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. +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. Optionally, you -can change this by suffixing the container-id with either the `ro` or -`rw` keyword. +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` +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. @@ -1010,17 +997,17 @@ that data on the target. **--workdir**, **-w**=*dir* -Working directory inside the container +Working directory inside the container. -The default working directory for running binaries within a container is the root directory (/). +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` standard, see below: +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 @@ -1050,26 +1037,24 @@ the exit codes follow the `chroot` standard, see below: ### 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, +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. +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. +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. +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 @@ -1093,7 +1078,7 @@ This should list the message sent to logger. ### Attaching to one or more from STDIN, STDOUT, STDERR -If you do not specify -a then Podman will attach everything (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: @@ -1103,9 +1088,9 @@ $ 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 +Using **shm_server.c** available here: https://www.cs.cf.ac.uk/Dave/C/node27.html -Testing `--ipc=host` mode: +Testing **--ipc=host** mode: Host shows a shared memory segment with 7 pids attached, happens to be from httpd: @@ -1126,7 +1111,7 @@ $ podman run -it shm ipcs -m 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: +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 @@ -1135,7 +1120,7 @@ $ podman run -it --ipc=host shm ipcs -m key shmid owner perms bytes nattch status 0x01128e25 0 root 600 1000 7 ``` -Testing `--ipc=container:CONTAINERID` mode: +Testing **--ipc=container:**_id_ mode: Start a container with a program to create a shared memory segment: ``` @@ -1155,7 +1140,7 @@ $ podman run shm ipcs -m key shmid owner perms bytes nattch status ``` -Create a 3rd container using the new --ipc=container:CONTAINERID option, now it shows the shared memory segment from the first: +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 @@ -1182,7 +1167,7 @@ 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's recommended to use it's 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`: +considered as an orphan and wiped if you execute **podman volume prune**: ``` $ podman run -v /var/db:/data1 -i -t fedora bash @@ -1190,7 +1175,7 @@ $ podman run -v /var/db:/data1 -i -t fedora bash $ podman run -v data:/data2 -i -t fedora bash ``` -Using --mount flags, To mount a host directory as a container folder, specify +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: @@ -1202,8 +1187,8 @@ $ 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. +_/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 @@ -1213,13 +1198,13 @@ 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. +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 +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. @@ -1234,7 +1219,7 @@ $ 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: +**--permissive** flag, use the following command: ``` $ podman run --security-opt label=disable -i -t fedora bash @@ -1249,14 +1234,12 @@ 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. +Note you would have to write policy defining a **svirt_apache_t** type. ### 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: +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 @@ -1264,7 +1247,7 @@ $ podman run -it --blkio-weight-device "/dev/sda:200" ubuntu ### Setting Namespaced Kernel Parameters (Sysctls) -The `--sysctl` sets namespaced kernel parameters (sysctls) in the +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: @@ -1272,13 +1255,11 @@ network namespace, run this command: $ podman run --sysctl net.ipv4.ip_forward=1 someimage ``` -Note: - -Not all sysctls are namespaced. Podman does not support changing sysctls +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 +See the definition of the **--sysctl** option above for the current list of supported sysctls. ### Set UID/GID mapping in a new user namespace @@ -1293,45 +1274,43 @@ $ 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 +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 +``` ### 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. +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. Note: RHEL7 and Centos 7 will not have this feature until RHEL7.7 is released. -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. +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-overlay 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. +The **fuse-overlay** 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. +Environment variables within containers can be set using multiple different options, +in the following order of precedence: -Precedence Order: +- **--env-host**: Host environment of the process executing Podman is added. +- 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. - **--env-host** : Host environment of the process executing Podman is added. - - 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. - -Run containers and set the environment ending with a __*__ and a ***** +Run containers and set the environment ending with a __*__ and a __*****__: ``` $ export ENV1=a -$ $ podman run --env ENV* alpine printenv ENV1 +$ podman run --env ENV* alpine printenv ENV1 a $ podman run --env ENV*****=b alpine printenv ENV***** @@ -1341,10 +1320,11 @@ b ## FILES **/etc/subuid** + **/etc/subgid** ## SEE ALSO -subgid(5), subuid(5), libpod.conf(5), systemd.unit(5), setsebool(8), slirp4netns(1), fuse-overlayfs(1) +**subgid**(5), **subuid**(5), **libpod.conf**(5), **systemd.unit**(5), **setsebool**(8), **slirp4netns**(1), **fuse-overlayfs**(1). ## HISTORY September 2018, updated by Kunal Kushwaha <kushwaha_kunal_v7@lab.ntt.co.jp> |