DOCKER(1)                          JUNE 2014                         DOCKER(1)

       docker-run - Run a command in a new container

       docker run [-a|--attach[=[]]] [--add-host[=[]]]
       [--blkio-weight[=[BLKIO-WEIGHT]]] [--blkio-weight-device[=[]]]
       [--cpu-shares[=0]] [--cap-add[=[]]] [--cap-drop[=[]]]
       [--cgroup-parent[=CGROUP-PATH]] [--cidfile[=CIDFILE]] [--cpu-count[=0]]
       [--cpu-percent[=0]] [--cpu-period[=0]] [--cpu-quota[=0]]
       [--cpu-rt-period[=0]] [--cpu-rt-runtime[=0]] [--cpus[=0.0]]
       [--cpuset-cpus[=CPUSET-CPUS]] [--cpuset-mems[=CPUSET-MEMS]]
       [-d|--detach] [--detach-keys[=[]]] [--device[=[]]]
       [--device-cgroup-rule[=[]]] [--device-read-bps[=[]]]
       [--device-read-iops[=[]]] [--device-write-bps[=[]]]
       [--device-write-iops[=[]]] [--dns[=[]]] [--dns-option[=[]]]
       [--dns-search[=[]]] [-e|--env[=[]]] [--entrypoint[=ENTRYPOINT]]
       [--env-file[=[]]] [--expose[=[]]] [--group-add[=[]]]
       [-h|--hostname[=HOSTNAME]] [--help] [--init] [-i|--interactive]
       [--ip[=IPv4-ADDRESS]] [--ip6[=IPv6-ADDRESS]] [--ipc[=IPC]]
       [--isolation[=default]] [--kernel-memory[=KERNEL-MEMORY]]
       [-l|--label[=[]]] [--label-file[=[]]] [--link[=[]]]
       [--link-local-ip[=[]]] [--log-driver[=[]]] [--log-opt[=[]]]
       [-m|--memory[=MEMORY]] [--mac-address[=MAC-ADDRESS]]
       [--memory-reservation[=MEMORY-RESERVATION]] [--memory-swap[=LIMIT]]
       [--memory-swappiness[=MEMORY-SWAPPINESS]] [--mount[=[MOUNT]]]
       [--name[=NAME]] [--network-alias[=[]]] [--network[="bridge"]]
       [--oom-kill-disable] [--oom-score-adj[=0]] [-P|--publish-all]
       [-p|--publish[=[]]] [--pid[=[PID]]] [--userns[=[]]]
       [--pids-limit[=PIDS_LIMIT]] [--privileged] [--read-only]
       [--restart[=RESTART]] [--rm] [--security-opt[=[]]] [--storage-opt[=[]]]
       [--stop-signal[=SIGNAL]] [--stop-timeout[=TIMEOUT]] [--shm-size[=[]]]
       [--sig-proxy[=true]] [--sysctl[=[]]] [-t|--tty]
       [--tmpfs[=[CONTAINER-DIR[:OPTIONS]]] [-u|--user[=USER]] [--ulimit[=[]]]
       [--uts[=[]]] [-v|--volume[=[[HOST-DIR:]CONTAINER-DIR[:OPTIONS]]]]
       [--volume-driver[=DRIVER]] [--volumes-from[=[]]]
       [-w|--workdir[=WORKDIR]] IMAGE [COMMAND] [ARG...]

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

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

       -a, --attach=[]
          Attach to STDIN, STDOUT or STDERR.

       In foreground mode (the default when -d is not specified), docker 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 commandline executables expect)
       and pass along signals. The -a option can be set for each of stdin,
       stdout, and stderr.

          Add a custom host-to-IP mapping (host:ip)

       Add a line to /etc/hosts. The format is hostname:ip.  The --add-host
       option can be set multiple times.

          Block IO weight (relative weight) accepts a weight value between 10
       and 1000.

          Block IO weight (relative device weight, format:

          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.

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

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

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

       For example, consider a system with more than three cores. If you start
       one container {C0} with -c=512 running one process, and another
       container {C1} with -c=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

          Add Linux capabilities

          Drop Linux capabilities

          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.

          Write the container ID to the file

           Limit the number of CPUs available for execution by the container.

              On Windows Server containers, this is approximated as a percentage of total CPU usage.

              On Windows Server containers, the processor resource controls are mutually exclusive, the order of precedence is CPUCount first, then CPUShares, and CPUPercent last.

           Limit the percentage of CPU available for execution by a container
       running on a Windows daemon.

              On Windows Server containers, the processor resource controls are mutually exclusive, the order of precedence is CPUCount first, then CPUShares, and CPUPercent last.

          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.

          CPUs in which to allow execution (0-3, 0,1)

          Memory nodes (MEMs) in which to allow execution (0-3, 0,1). 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 Docker container will only use
       memory from the first two memory nodes.

          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 to the quota you specify.

          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.

          Limit the CPU real-time runtime in microseconds

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

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

          Number of CPUs. The default is 0.0 which means no limit.

       -d, --detach=true|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 docker ps in the other shell to view a list of
       the running containers. You can reattach to a detached container with
       docker 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.  You configure the key sequence using the
       --detach-keys option or a configuration file.  See config-json(5) for
       documentation on using a configuration file.

          Override the key sequence for detaching a container; key is a single
       character from the [a-Z] range, or ctrl-value, where value is one of:
       a-z, @, ^, [, ,, or _.

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

       For example, --device=/dev/sdc:/dev/xvdc:rwm will give a container all
       permissions for the host device /dev/sdc, seen as /dev/xvdc inside the

       --device-cgroup-rule="type major:minor mode"
          Add a rule to the cgroup allowed devices list. The rule is expected
       to be in the format specified in the Linux kernel documentation
            - type: a (all), c (char), or b (block);
            - major and minor: either a number, or * for all;
            - mode: a composition of r (read), w (write), and m (mknod(2)).

       Example: --device-cgroup-rule "c 1:3 mr": allow for a character device
       idendified by 1:3  to be created and read.

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

          Limit read rate from a device (e.g.

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

          Limit write rate to a device (e.g.

          Set custom DNS search domains (Use --dns-search=. if you don't wish
       to set the search domain)

          Set custom DNS options

          Set custom DNS servers

       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., When this is the case
       the --dns flags is necessary for every run.

       -e, --env=[]
          Set environment variables

       This option allows you to specify arbitrary environment variables that
       are available for the process that will be launched inside of the

          Overwrite the default ENTRYPOINT of the image

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

          Read in a line delimited file of environment variables

          Expose a port, or a range of ports (e.g. --expose=3300-3310) informs
       Docker that the container listens on the specified network ports at
       runtime. Docker uses this information to interconnect containers using
       links and to set up port redirection on the host system.

          Add additional groups to run as

       -h, --hostname=""
          Container host name

       Sets the container host name that is available inside the container.

          Print usage statement

          Run an init inside the container that forwards signals and reaps

       -i, --interactive=true|false
          Keep STDIN open even if not attached. The default is false.

       When set to true, keep stdin open even if not attached.

          Sets the container's interface IPv4 address (e.g.,

       It can only be used in conjunction with --network for user-defined

          Sets the container's interface IPv6 address (e.g., 2001:db8::1b99)

       It can only be used in conjunction with --network for user-defined

          Sets the IPC mode for the container. The following values are

       |Value                | Description                |
       |(empty)              | Use daemon's default.      |
       |none                 | Own private IPC namespace, |
       |                     | with /dev/shm not mounted. |
       |private              | Own private IPC namespace. |
       |shareable            | Own private IPC namespace, |
       |                     | with a possibility to      |
       |                     | share it with other        |
       |                     | containers.                |
       |container:name-or-ID | Join another ("shareable") |
       |                     | container's IPC namespace. |
       |host                 | Use the host system's IPC  |
       |                     | namespace.                 |

       If not specified, daemon default is used, which can either be private
       or shareable, depending on the daemon version and configuration.

          Isolation specifies the type of isolation technology used by
       containers. Note that the default on Windows server is process, and the
       default on Windows client is hyperv. Linux only supports default.

       -l, --label key=value
          Set metadata on the container (for example, --label

          Kernel memory limit; S is an optional suffix which can be one of b,
       k, m, or g.

       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 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.

          Read in a line delimited file of labels

          Add link to another container.

       If the operator uses --link when starting the new client container,
       then the client container can access the exposed port via a private
       networking interface. Docker will set some environment variables in the
       client container to help indicate which interface and port to use.

          Add one or more link-local IPv4/IPv6 addresses to the container's

         Logging driver for the container. Default is defined by daemon
       --log-driver flag.
         Warning: the docker logs command works only for the json-file and
         journald logging drivers.

         Logging driver specific options.

       -m, --memory=number[*S]
          Memory limit; S is an optional suffix which can be one of b, k, m,
       or g.

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

          Memory soft limit; S is an optional suffix which can be one of b, k,
       m, or g.

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

          Combined memory plus swap limit; S is an optional suffix which can
       be one of b, k, m, or g.

       This option can only be used together with --memory. The argument
       should always be larger than that of --memory. Default is double the
       value of --memory. Set to -1 to enable unlimited swap.

          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
       according to RFC4862.

       --mount type=TYPE,TYPE-SPECIFIC-OPTION[,...]
          Attach a filesystem mount to the container

       Current supported mount TYPES are bind, volume, and tmpfs.





       Common Options:

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

              o dst, destination, target: mount destination spec.

              o ro, read-only: true or false (default).

       Options specific to bind:

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

              o consistency: consistent(default), cached, or delegated.
                Currently, only effective for Docker for Mac.

       Options specific to volume:

              o volume-driver: Name of the volume-driver plugin.

              o volume-label: Custom metadata.

              o volume-nocopy: true(default) or false. If set to false, the
                Engine copies existing files and directories under the
                mount-path into the volume, allowing the host to access them.

              o volume-opt: specific to a given volume driver.

       Options specific to tmpfs:

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

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

          Assign a name to the container

       The operator can identify a container in three ways:

       |Identifier type       | Example value                                                      |
       |UUID long identifier  | "f78375b1c487e03c9438c729345e54db9d20cfa2ac1fc3494b6eb60872e74778" |
       |UUID short identifier | "f78375b1c487"                                                     |
       |Name                  | "evil_ptolemy"                                                     |

       The UUID identifiers come from the Docker daemon, and if a name is not
       assigned to the container with --name then the daemon will also
       generate a random string name. The name is useful when defining links
       (see --link) (or any other place you need to identify a container).
       This works for both background and foreground Docker containers.

          Set the Network mode for the container. Supported values are:

       |Value          | Description               |
       |none           | No networking in the      |
       |               | container.                |
       |bridge         | Connect the container to  |
       |               | the default Docker bridge |
       |               | via veth interfaces.      |
       |host           | Use the host's network    |
       |               | stack inside the          |
       |               | container.                |
       |container:name | id                        |
       |network-name   | network-id                |

       Default is bridge.

          Add network-scoped alias for the container

          Whether to disable OOM Killer for the container or not.

          Tune the host's OOM preferences for containers (accepts -1000 to

       -P, --publish-all=true|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 Docker 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, Docker 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 docker

       -p, --publish ip:[hostPort]:containerPort | [hostPort:]containerPort
          Publish a container's port, or range of ports, to the host.

       Both hostPort and containerPort can be specified as a range.  When
       specifying ranges for both, the number of ports in ranges should be

       Examples: -p 1234-1236:1222-1224, -p$HOSTPORT:$CONTAINERPORT.

       Use docker port(1) to see the actual mapping, e.g. docker port

          Set the PID mode for the container
          Default 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.

          Set the usernamespace mode for the container when userns-remap
       option is enabled.
            host: use the host usernamespace and enable all privileged options
       (e.g., pid=host or --privileged).

          Tune the container's pids (process IDs) limit. Set to -1 to have
       unlimited pids for the container.

          Set the UTS mode for the container. The only possible type is host,
       meaning to use the host's UTS namespace inside the container.
            Note: the host mode gives the container access to changing the
       host's hostname and is therefore considered insecure.

       --privileged [true|false]
          Give extended privileges to this container. A "privileged" container
       is given access to all devices.

       When the operator executes docker run --privileged, Docker will enable
       access to all devices on the host as well as set some configuration in
       AppArmor to allow the container nearly all the same access to the host
       as processes running outside of a container on the host.

          Mount the container's root filesystem as read only.

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

       --restart policy
          Restart policy to apply when a container exits. Supported values

       |Policy                   | Result                     |
       |no                       | Do not automatically       |
       |                         | restart the container when |
       |                         | it exits.                  |
       |on-failure[:max-retries] | Restart only if the        |
       |                         | container exits with a     |
       |                         | non-zero exit status.      |
       |                         | Optionally, limit the      |
       |                         | number of restart retries  |
       |                         | the Docker daemon          |
       |                         | attempts.                  |
       |always                   | Always restart the         |
       |                         | container regardless of    |
       |                         | the exit status. When you  |
       |                         | specify always, the Docker |
       |                         | daemon will try to restart |
       |                         | the container              |
       |                         | indefinitely. The          |
       |                         | container will also always |
       |                         | start on daemon startup,   |
       |                         | regardless of the current  |
       |                         | state of the container.    |
       |unless-stopped           | Always restart the         |
       |                         | container regardless of    |
       |                         | the exit status, but do    |
       |                         | not start it on daemon     |
       |                         | startup if the container   |
       |                         | has been put to a stopped  |
       |                         | state before.              |

       Default is no.

       --rm true|false
          Automatically remove the container when it exits. The default is
          --rm flag can work together with -d, and auto-removal will be done
       on daemon side. Note that it's incompatible with any restart policy
       other than none.

       --security-opt value[,...]
          Security Options for the container. The following options can be

              "label=user:USER"   : Set the label user for the container
              "label=role:ROLE"   : Set the label role for the container
              "label=type:TYPE"   : Set the label type for the container
              "label=level:LEVEL" : Set the label level for the container
              "label=disable"     : Turn off label confinement 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 :  White listed syscalls seccomp Json file to be used as a seccomp filter

              "apparmor=unconfined" : Turn off apparmor confinement for the container
              "apparmor=your-profile" : Set the apparmor confinement profile for the container

          Storage driver options per container

       $ docker run -it --storage-opt size=120G fedora /bin/bash

       This (size) will allow to set the container rootfs size to 120G at
       creation time.
          This option is only available for the devicemapper, btrfs, overlay2
       and zfs graph drivers.
          For the devicemapper, btrfs and zfs storage drivers, user cannot
       pass a size less than the Default BaseFS Size.
          For the overlay2 storage driver, the size option is only available
       if the backing fs is xfs and mounted with the pquota mount option.
          Under these conditions, user can pass any size less than the backing
       fs size.

         Signal to stop a container. Default is SIGTERM.

         Timeout (in seconds) to stop a container. Default is 10.

          Size of /dev/shm. The format is <number><unit>.
          number must be greater than 0.  Unit is optional and 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 system uses 64m.

         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.*

       If you use the --ipc=host option these sysctls will not be allowed.

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

       If you use the --network=host option these sysctls will not be allowed.

          Proxy received signals to the process (non-TTY mode only). SIGCHLD,
       SIGSTOP, and SIGKILL are not proxied. The default is true.

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

       -t, --tty=true|false
          Allocate a pseudo-TTY. The default is false.

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

       The -t option is incompatible with a redirection of the docker client
       standard input.

       --tmpfs=[] Create a tmpfs mount

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

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

       This command mounts a tmpfs at /tmp within the container.  The
       supported mount options are the same as the Linux default mount flags.
       If you do not specify any options, the systems uses the following
       options: rw,noexec,nosuid,nodev,size=65536k.

       See also --mount, which is the successor of --tmpfs and --volume.
          Even though there is no plan to deprecate --tmpfs, usage of --mount
       is recommended.

       -u, --user=""
          Sets the username or UID used and optionally the groupname or GID
       for the specified command.

       The followings 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.

           Ulimit options

          Create a bind mount. If you specify, -v /HOST-DIR:/CONTAINER-DIR,
          bind mounts /HOST-DIR in the host to /CONTAINER-DIR in the Docker
          container. If 'HOST-DIR' is omitted,  Docker automatically creates
       the new
          volume on the host.  The OPTIONS are a comma delimited list and can

              o [rw|ro]

              o [z|Z]

              o [[r]shared|[r]slave|[r]private]

              o [delegated|cached|consistent]

              o [nocopy]

       The CONTAINER-DIR must be an absolute path such as /src/docs. The
       HOST-DIR can be an absolute path or a name value. A name value must
       start with an alphanumeric character, followed by a-z0-9, _
       (underscore), . (period) or - (hyphen). An absolute path starts with a
       / (forward slash).

       If you supply a HOST-DIR that is an absolute path,  Docker bind-mounts
       to the path you specify. If you supply a name, Docker creates a named
       volume by that name. For example, you can specify either /foo or foo
       for a HOST-DIR value. If you supply the /foo value, Docker creates a
       bind mount. If you supply the foo specification, Docker creates a named

       You can specify multiple  -v options to mount one or more mounts to a
       container. To use these same mounts in other containers, specify the
       --volumes-from option also.

       You can supply additional options for each bind mount following an
       additional colon.  A :ro or :rw suffix mounts a volume in read-only or
       read-write mode, respectively. By default, volumes are mounted in
       read-write mode.  You can also specify the consistency requirement for
       the mount, either :consistent (the default), :cached, or :delegated.
       Multiple options are separated by commas, e.g. :ro,cached.

       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, Docker 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 Docker to
       relabel file objects on the shared volumes. The z option tells Docker
       that two containers share the volume content. As a result, Docker
       labels the content with a shared content label. Shared volume labels
       allow all containers to read/write content.  The Z option tells Docker
       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
       inside container will not be visible on host and vice-a-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-a-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

       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.

       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.

       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: When using systemd to manage the Docker daemon's start and
              stop, in the systemd unit file there is an option to control
              mount propagation for the Docker daemon itself, called
              MountFlags. The value of this setting may cause Docker to not
              see mount propagation changes made on the mount point. For
              example, if this value is slave, you may not be able to use the
              shared or rshared propagation on a volume.

       To disable automatic copying of data from the container path to the
       volume, use the nocopy flag. The nocopy flag can be set on bind mounts
       and named volumes.

       See also --mount, which is the successor of --tmpfs and --volume.  Even
       though there is no plan to deprecate --volume, usage of --mount is

          Container's volume driver. This driver creates volumes specified
       either from
          a Dockerfile's VOLUME instruction or from the docker run -v flag.
          See docker-volume-create(1) for full details.

          Mount volumes from the specified container(s)

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

       By default, Docker 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.

       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.

       -w, --workdir=""
          Working directory inside the container

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

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

       125 if the error is with Docker daemon itself

              $ docker run --foo busybox; echo $?
              # flag provided but not defined: --foo
                See 'docker run --help'.

       126 if the contained command cannot be invoked

              $ docker run busybox /etc; echo $?
              # exec: "/etc": permission denied
                docker: Error response from daemon: Contained command could not be invoked

       127 if the contained command cannot be found

              $ docker run busybox foo; echo $?
              # exec: "foo": executable file not found in $PATH
                docker: Error response from daemon: Contained command not found or does not exist

       Exit code of contained command otherwise

              $ docker run busybox /bin/sh -c 'exit 3'
              # 3

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

              # docker run --read-only --tmpfs /run --tmpfs /tmp -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.

              # docker run -v /dev/log:/dev/log -i -t fedora /bin/bash

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

              (bash)# logger "Hello from my container"

       Then exit and check the journal.

              # exit

              # journalctl -b | grep Hello

       This should list the message sent to logger.

Attaching to one or more from STDIN, STDOUT, STDERR
       If you do not specify -a then Docker will attach everything
       (stdin,stdout,stderr) you'd like to connect instead, as in:

              # docker run -a stdin -a stdout -i -t fedora /bin/bash

Sharing IPC between containers
       Using shm_server.c available here:

       Testing --ipc=host mode:

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

               $ sudo ipcs -m

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

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

               $ docker run -it shm ipcs -m

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

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

               $ docker run -it --ipc=host shm ipcs -m

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

       Testing --ipc=container:CONTAINERID mode:

       Start a container with a program to create a shared memory segment:

               $ docker run -it shm bash
               $ sudo shm/shm_server
               $ sudo ipcs -m

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

       Create a 2nd container correctly shows no shared memory segment from
       1st container:

               $ docker run shm ipcs -m

               ------ Shared Memory Segments --------
               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:

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

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

Linking Containers
              Note: This section describes linking between containers on the
              default (bridge) network, also known as "legacy links". Using
              --link on user-defined networks uses the DNS-based discovery,
              which does not add entries to /etc/hosts, and does not set
              environment variables for discovery.

       The link feature allows multiple containers to communicate with each
       other. For example, a container whose Dockerfile has exposed port 80
       can be run and named as follows:

              # docker run --name=link-test -d -i -t fedora/httpd

       A second container, in this case called linker, can communicate with
       the httpd container, named link-test, by running with the

              # docker run -t -i --link=link-test:lt --name=linker fedora /bin/bash

       Now the container linker is linked to container link-test with the
       alias lt.  Running the env command in the linker container shows
       environment variables
        with the LT (alias) context (LT_)

              # env

       When linking two containers Docker will use the exposed ports of the
       container to create a secure tunnel for the parent to access.

       If a container is connected to the default bridge network and linked
       with other containers, then the container's /etc/hosts file is updated
       with the linked container's name.

              Note Since Docker may live update the container's /etc/hosts
              file, there may be situations when processes inside the
              container can end up reading an empty or incomplete /etc/hosts
              file. In most cases, retrying the read again should fix the

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

              # docker run -p 8080:80 -d -i -t fedora/httpd

Creating and Mounting a Data Volume Container
       Many applications require the sharing of persistent data across several
       containers. Docker allows you to create a Data Volume Container that
       other containers can mount from. For example, create a named container
       that contains directories /var/volume1 and /tmp/volume2. The image will
       need to contain these directories so a couple of RUN mkdir instructions
       might be required for you fedora-data image:

              # docker run --name=data -v /var/volume1 -v /tmp/volume2 -i -t fedora-data true
              # docker run --volumes-from=data --name=fedora-container1 -i -t fedora bash

       Multiple --volumes-from parameters will bring together multiple data
       volumes from multiple containers. And it's possible to mount the
       volumes that came from the DATA container in yet another container via
       the fedora-container1 intermediary container, allowing to abstract the
       actual data source from users of that data:

              # docker run --volumes-from=fedora-container1 --name=fedora-container2 -i -t fedora bash

Mounting External Volumes
       To mount a host directory as a container volume, specify the absolute
       path to the directory and the absolute path for the container directory
       separated by a colon:

              # docker run -v /var/db:/data1 -i -t fedora bash

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

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

              # chcon -Rt svirt_sandbox_file_t /var/db

       Now, writing to the /data1 volume in the container will be allowed and
       the changes will also be reflected on the host in /var/db.

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

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

       An MLS example might be:

              # docker 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:

              # docker run --security-opt label=disable -i -t fedora bash

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

              # docker run --security-opt label=type:svirt_apache_t -i -t centos bash


       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:

              # docker run -it --blkio-weight-device "/dev/sda:200" ubuntu

Specify isolation technology for container (--isolation)
       This option is useful in situations where you are running Docker
       containers on Microsoft Windows. The --isolation <value> option sets a
       container's isolation technology. On Linux, the only supported is the
       default option which uses Linux namespaces. These two commands are
       equivalent on Linux:

              $ docker run -d busybox top
              $ docker run -d --isolation default busybox top

       On Microsoft Windows, can take any of these values:

              o default: Use the value specified by the Docker daemon's
                --exec-opt . If the daemon does not specify an isolation
                technology, Microsoft Windows uses process as its default

              o process: Namespace isolation only.

              o hyperv: Hyper-V hypervisor partition-based isolation.

       In practice, when running on Microsoft Windows without a daemon option
       set,  these two commands are equivalent:

              $ docker run -d --isolation default busybox top
              $ docker run -d --isolation process busybox top

       If you have set the --exec-opt isolation=hyperv option on the Docker
       daemon, any of these commands also result in hyperv isolation:

              $ docker run -d --isolation default busybox top
              $ docker run -d --isolation hyperv busybox top

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

              $ docker run --sysctl net.ipv4.ip_forward=1 someimage


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

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

       April 2014, Originally compiled by William Henry (whenry at redhat dot
       com) based on source material and internal work.  June 2014,
       updated by Sven Dowideit <> July 2014, updated
       by Sven Dowideit <> November 2015, updated by
       Sally O'Malley <>

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