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  Docker runs processes in isolated containers. A container is a process
  which runs on a host. The host may be local or remote. When you
  execute
  docker run
  , the container process that runs is isolated in
  that it has its own file system, its own networking, and its own
  isolated process tree separate from the host.
  This page details how to use the
  docker run
  command to run containers.
  General form
  docker run
  command takes the following form:
  docker run
  OPTIONS
  IMAGE
  :TAG
  @DIGEST
  COMMAND
  ARG...
  docker run
  command must specify an
  image reference
  to create the container from.
  Image references
  The image reference is the name and version of the image. You can use the image
  reference to create or run a container based on an image.
  docker run IMAGE[:TAG][@DIGEST]
  docker create IMAGE[:TAG][@DIGEST]
  An image tag is the image version, which defaults to
  latest
  when omitted. Use
  the tag to run a container from specific version of an image. For example, to
  run version
  of the
  ubuntu
  image:
  docker run ubuntu:24.04
  Image digests
  Images using the v2 or later image format have a content-addressable identifier
  called a digest. As long as the input used to generate the image is unchanged,
  the digest value is predictable.
  The following example runs a container from the
  alpine
  image with the
  sha256:9cacb71397b640eca97488cf08582ae4e4068513101088e9f96c9814bfda95e0
  digest:
  docker run alpine@sha256:9cacb71397b640eca97488cf08582ae4e4068513101088e9f96c9814bfda95e0 date
  Options
  [OPTIONS]
  let you configure options for the container. For example, you can
  give the container a name (
  --name
  ), or run it as a background process (
  You can also set options to control things like resource constraints and
  networking.
  Commands and arguments
  You can use the
  [COMMAND]
  [ARG...]
  positional arguments to specify
  commands and arguments for the container to run when it starts up. For example,
  you can specify
  as the
  [COMMAND]
  , combined with the
  flags,
  to start an interactive shell in the container (if the image you select has an
  executable on
  PATH
  docker run -it IMAGE sh
  Note
  Depending on your Docker system configuration, you may be
  required to preface the
  docker run
  command with
  sudo
  . To avoid
  having to use
  sudo
  with the
  docker
  command, your system
  administrator can create a Unix group called
  docker
  and add users to
  it. For more information about this configuration, refer to the Docker
  installation documentation for your operating system.
  Foreground and background
  When you start a container, the container runs in the foreground by default.
  If you want to run the container in the background instead, you can use the
  --detach
  ) flag. This starts the container without occupying your
  terminal window.
  docker run -d <IMAGE>
  While the container runs in the background, you can interact with the container
  using other CLI commands. For example,
  docker logs
  lets you view the logs for
  the container, and
  docker attach
  brings it to the foreground.
  docker run -d nginx
  0246aa4d1448a401cabd2ce8f242192b6e7af721527e48a810463366c7ff54f1
  docker ps
  CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
  0246aa4d1448 nginx "/docker-entrypoint.â¦" 2 seconds ago Up 1 second 80/tcp pedantic_liskov
  docker logs -n
  0246aa4d1448
  2023/11/06 15:58:23 [notice] 1#1: start worker process 33
  2023/11/06 15:58:23 [notice] 1#1: start worker process 34
  2023/11/06 15:58:23 [notice] 1#1: start worker process 35
  2023/11/06 15:58:23 [notice] 1#1: start worker process 36
  2023/11/06 15:58:23 [notice] 1#1: start worker process 37
  docker attach 0246aa4d1448
  2023/11/06 15:58:40 [notice] 1#1: signal 2 (SIGINT) received, exiting
  For more information about
  docker run
  flags related to foreground and
  background modes, see:
  docker run --detach
  : run container in background
  docker run --attach
  : attach to
  stdin
  stdout
  , and
  stderr
  docker run --tty
  : allocate a pseudo-tty
  docker run --interactive
  : keep
  stdin
  open even if not attached
  For more information about re-attaching to a background container, see
  docker attach
  Container identification
  You can identify a container in three ways:
  Identifier type
  Example value
  UUID long identifier
  f78375b1c487e03c9438c729345e54db9d20cfa2ac1fc3494b6eb60872e74778
  UUID short identifier
  f78375b1c487
  Name
  evil_ptolemy
  The UUID identifier is a random ID assigned to the container by the daemon.
  The daemon generates a random string name for containers automatically. You can
  also define a custom name using
  --name
  flag
  Defining a
  name
  can be a handy way to add meaning to a container. If you
  specify a
  name
  , you can use it when referring to the container in a
  user-defined network. This works for both background and foreground Docker
  containers.
  A container identifier is not the same thing as an image reference. The image
  reference specifies which image to use when you run a container. You can't run
  docker exec nginx:alpine sh
  to open a shell in a container based on the
  nginx:alpine
  image, because
  docker exec
  expects a container identifier
  (name or ID), not an image.
  While the image used by a container is not an identifier for the container, you
  find out the IDs of containers using an image by using the
  --filter
  flag. For
  example, the following
  docker ps
  command gets the IDs of all running
  containers based on the
  nginx:alpine
  image:
  docker ps -q --filter
  ancestor
  nginx:alpine
  For more information about using filters, see
  Filtering
  Container networking
  Containers have networking enabled by default, and they can make outgoing
  connections. If you're running multiple containers that need to communicate
  with each other, you can create a custom network and attach the containers to
  the network.
  When multiple containers are attached to the same custom network, they can
  communicate with each other using the container names as a DNS hostname. The
  following example creates a custom network named
  my-net
  , and runs two
  containers that attach to the network.
  docker network create my-net
  docker run -d --name web --network my-net nginx:alpine
  docker run --rm -it --network my-net busybox
  / # ping web
  PING web (172.18.0.2): 56 data bytes
  64 bytes from 172.18.0.2: seq=0 ttl=64 time=0.326 ms
  64 bytes from 172.18.0.2: seq=1 ttl=64 time=0.257 ms
  64 bytes from 172.18.0.2: seq=2 ttl=64 time=0.281 ms
  --- web ping statistics ---
  3 packets transmitted, 3 packets received, 0% packet loss
  round-trip min/avg/max = 0.257/0.288/0.326 ms
  For more information about container networking, see
  Networking
  overview
  Filesystem mounts
  By default, the data in a container is stored in an ephemeral, writable
  container layer. Removing the container also removes its data. If you want to
  use persistent data with containers, you can use filesystem mounts to store the
  data persistently on the host system. Filesystem mounts can also let you share
  data between containers and the host.
  Docker supports two main categories of mounts:
  Volume mounts
  Bind mounts
  Volume mounts are great for persistently storing data for containers, and for
  sharing data between containers. Bind mounts, on the other hand, are for
  sharing data between a container and the host.
  You can add a filesystem mount to a container using the
  --mount
  flag for the
  docker run
  command.
  The following sections show basic examples of how to create volumes and bind
  mounts. For more in-depth examples and descriptions, refer to the section of
  storage section
  in the documentation.
  Volume mounts
  To create a volume mount:
  docker run --mount
  source
  <VOLUME_NAME>,target
  PATH
  IMAGE
  COMMAND...
  --mount
  flag takes two parameters in this case:
  source
  target
  The value for the
  source
  parameter is the name of the volume. The value of
  target
  is the mount location of the volume inside the container. Once you've
  created the volume, any data you write to the volume is persisted, even if you
  stop or remove the container:
  docker run --rm --mount
  source
  my_volume,target
  /foo busybox
  echo "hello, volume!" > /foo/hello.txt
  docker run --mount
  source
  my_volume,target
  /bar busybox
  cat /bar/hello.txt
  hello, volume!
  target
  must always be an absolute path, such as
  /src/docs
  . An absolute
  path starts with a
  (forward slash). Volume names must start with an
  alphanumeric character, followed by
  a-z0-9
  (underscore),
  (period) or
  (hyphen).
  Bind mounts
  To create a bind mount:
  docker run -it --mount
  type
  bind,source
  PATH
  ,target
  PATH
  busybox
  In this case, the
  --mount
  flag takes three parameters. A type (
  bind
  ), and
  two paths. The
  source
  path is a the location on the host that you want to
  bind mount into the container. The
  target
  path is the mount destination
  inside the container.
  Bind mounts are read-write by default, meaning that you can both read and write
  files to and from the mounted location from the container. Changes that you
  make, such as adding or editing files, are reflected on the host filesystem:
  docker run -it --mount
  type
  bind,source
  .,target
  /foo busybox
  / # echo "hello from container" > /foo/hello.txt
  / # exit
  cat hello.txt
  hello from container
  Exit status
  The exit code from
  docker run
  gives information about why the container
  failed to run or why it exited. The following sections describe the meanings of
  different container exit codes values.
  Exit code
  indicates that the error is with Docker daemon itself.
  docker run --foo busybox
  echo
  flag provided but not defined: --foo
  See 'docker run --help'.
  Exit code
  indicates that the specified contained command can't be invoked.
  The container command in the following example is:
  /etc
  docker run busybox /etc
  echo
  docker: Error response from daemon: Container command '/etc' could not be invoked.
  Exit code
  indicates that the contained command can't be found.
  docker run busybox foo
  echo
  docker: Error response from daemon: Container command 'foo' not found or does not exist.
  Other exit codes
  Any exit code other than
  , and
  represent the exit code of the
  provided container command.
  docker run busybox /bin/sh -c
  'exit 3'
  echo
  Runtime constraints on resources
  The operator can also adjust the performance parameters of the
  container:
  Option
  Description
  --memory=""
  Memory limit (format:
  <number>[<unit>]
  ). Number is a positive integer. Unit can be one of
  , or
  . Minimum is 6M.
  --memory-swap=""
  Total memory limit (memory + swap, format:
  <number>[<unit>]
  ). Number is a positive integer. Unit can be one of
  , or
  --memory-reservation=""
  Memory soft limit (format:
  <number>[<unit>]
  ). Number is a positive integer. Unit can be one of
  , or
  --kernel-memory=""
  Kernel memory limit (format:
  <number>[<unit>]
  ). Number is a positive integer. Unit can be one of
  , or
  . Minimum is 4M.
  --cpu-shares=0
  CPU shares (relative weight)
  --cpus=0.000
  Number of CPUs. Number is a fractional number. 0.000 means no limit.
  --cpu-period=0
  Limit the CPU CFS (Completely Fair Scheduler) period
  --cpuset-cpus=""
  CPUs in which to allow execution (0-3, 0,1)
  --cpuset-mems=""
  Memory nodes (MEMs) in which to allow execution (0-3, 0,1). Only effective on NUMA systems.
  --cpu-quota=0
  Limit the CPU CFS (Completely Fair Scheduler) quota
  --cpu-rt-period=0
  Limit the CPU real-time period. In microseconds. Requires parent cgroups be set and cannot be higher than parent. Also check rtprio ulimits.
  --cpu-rt-runtime=0
  Limit the CPU real-time runtime. In microseconds. Requires parent cgroups be set and cannot be higher than parent. Also check rtprio ulimits.
  --blkio-weight=0
  Block IO weight (relative weight) accepts a weight value between 10 and 1000.
  --blkio-weight-device=""
  Block IO weight (relative device weight, format:
  DEVICE_NAME:WEIGHT
  --device-read-bps=""
  Limit read rate from a device (format:
  <device-path>:<number>[<unit>]
  ). Number is a positive integer. Unit can be one of
  , or
  --device-write-bps=""
  Limit write rate to a device (format:
  <device-path>:<number>[<unit>]
  ). Number is a positive integer. Unit can be one of
  , or
  --device-read-iops=""
  Limit read rate (IO per second) from a device (format:
  <device-path>:<number>
  ). Number is a positive integer.
  --device-write-iops=""
  Limit write rate (IO per second) to a device (format:
  <device-path>:<number>
  ). Number is a positive integer.
  --oom-kill-disable=false
  Whether to disable OOM Killer for the container or not.
  --oom-score-adj=0
  Tune container's OOM preferences (-1000 to 1000)
  --memory-swappiness=""
  Tune a container's memory swappiness behavior. Accepts an integer between 0 and 100.
  --shm-size=""
  Size of
  /dev/shm
  . The format is
  <number><unit>
  number
  must be greater than
  . Unit is optional and can be
  (bytes),
  (kilobytes),
  (megabytes), or
  (gigabytes). If you omit the unit, the system uses bytes. If you omit the size entirely, the system uses
  User memory constraints
  We have four ways to set user memory usage:
  Option
  Result
  memory=inf, memory-swap=inf
  (default)
  There is no memory limit for the container. The container can use
  as much memory as needed.
  memory=L<inf, memory-swap=inf
  (specify memory and set memory-swap as
  ) The container is
  not allowed to use more than L bytes of memory, but can use as much swap
  as is needed (if the host supports swap memory).
  memory=L<inf, memory-swap=2*L
  (specify memory without memory-swap) The container is not allowed to
  use more than L bytes of memory, swap
  plus
  memory usage is double
  of that.
  memory=L<inf, memory-swap=S<inf, L<=S
  (specify both memory and memory-swap) The container is not allowed to
  use more than L bytes of memory, swap
  plus
  memory usage is limited
  by S.
  Examples:
  docker run -it ubuntu:24.04 /bin/bash
  We set nothing about memory, this means the processes in the container can use
  as much memory and swap memory as they need.
  docker run -it -m 300M --memory-swap -1 ubuntu:24.04 /bin/bash
  We set memory limit and disabled swap memory limit, this means the processes in
  the container can use 300M memory and as much swap memory as they need (if the
  host supports swap memory).
  docker run -it -m 300M ubuntu:24.04 /bin/bash
  We set memory limit only, this means the processes in the container can use
  300M memory and 300M swap memory, by default, the total virtual memory size
  (--memory-swap) will be set as double of memory, in this case, memory + swap
  would be 2*300M, so processes can use 300M swap memory as well.
  docker run -it -m 300M --memory-swap 1G ubuntu:24.04 /bin/bash
  We set both memory and swap memory, so the processes in the container can use
  300M memory and 700M swap memory.
  Memory reservation is a kind of memory soft limit that allows for greater
  sharing of memory. Under normal circumstances, containers can use as much of
  the memory as needed and are constrained only by the hard limits set with the
  --memory
  option. When memory reservation is set, Docker detects memory
  contention or low memory and forces containers to restrict their consumption to
  a reservation limit.
  Always set the memory reservation value below the hard limit, otherwise the hard
  limit takes precedence. A reservation of 0 is the same as setting no
  reservation. By default (without reservation set), memory reservation is the
  same as the hard memory limit.
  Memory reservation is a soft-limit feature and does not guarantee the limit
  won't be exceeded. Instead, the feature attempts to ensure that, when memory is
  heavily contended for, memory is allocated based on the reservation hints/setup.
  The following example limits the memory (
  ) to 500M and sets the memory
  reservation to 200M.
  docker run -it -m 500M --memory-reservation 200M ubuntu:24.04 /bin/bash
  Under this configuration, when the container consumes memory more than 200M and
  less than 500M, the next system memory reclaim attempts to shrink container
  memory below 200M.
  The following example set memory reservation to 1G without a hard memory limit.
  docker run -it --memory-reservation 1G ubuntu:24.04 /bin/bash
  The container can use as much memory as it needs. The memory reservation setting
  ensures the container doesn't consume too much memory for long time, because
  every memory reclaim shrinks the container's consumption to the reservation.
  By default, kernel kills processes in a container if an out-of-memory (OOM)
  error occurs. To change this behaviour, use the
  --oom-kill-disable
  option.
  Only disable the OOM killer on containers where you have also set the
  -m/--memory
  option. If the
  flag is not set, this can result in the host
  running out of memory and require killing the host's system processes to free
  memory.
  The following example limits the memory to 100M and disables the OOM killer for
  this container:
  docker run -it -m 100M --oom-kill-disable ubuntu:24.04 /bin/bash
  The following example, illustrates a dangerous way to use the flag:
  docker run -it --oom-kill-disable ubuntu:24.04 /bin/bash
  The container has unlimited memory which can cause the host to run out memory
  and require killing system processes to free memory. The
  --oom-score-adj
  parameter can be changed to select the priority of which containers will
  be killed when the system is out of memory, with negative scores making them
  less likely to be killed, and positive scores more likely.
  Kernel memory constraints
  Kernel memory is fundamentally different than user memory as kernel memory can't
  be swapped out. The inability to swap makes it possible for the container to
  block system services by consuming too much kernel memory. Kernel memory includesï¼
  stack pages
  slab pages
  sockets memory pressure
  tcp memory pressure
  You can setup kernel memory limit to constrain these kinds of memory. For example,
  every process consumes some stack pages. By limiting kernel memory, you can
  prevent new processes from being created when the kernel memory usage is too high.
  Kernel memory is never completely independent of user memory. Instead, you limit
  kernel memory in the context of the user memory limit. Assume "U" is the user memory
  limit and "K" the kernel limit. There are three possible ways to set limits:
  Option
  Result
  U != 0, K = inf
  (default)
  This is the standard memory limitation mechanism already present before using
  kernel memory. Kernel memory is completely ignored.
  U != 0, K < U
  Kernel memory is a subset of the user memory. This setup is useful in
  deployments where the total amount of memory per-cgroup is overcommitted.
  Overcommitting kernel memory limits is definitely not recommended, since the
  box can still run out of non-reclaimable memory.
  In this case, you can configure K so that the sum of all groups is
  never greater than the total memory. Then, freely set U at the expense of
  the system's service quality.
  U != 0, K > U
  Since kernel memory charges are also fed to the user counter and reclamation
  is triggered for the container for both kinds of memory. This configuration
  gives the admin a unified view of memory. It is also useful for people
  who just want to track kernel memory usage.
  Examples:
  docker run -it -m 500M --kernel-memory 50M ubuntu:24.04 /bin/bash
  We set memory and kernel memory, so the processes in the container can use
  500M memory in total, in this 500M memory, it can be 50M kernel memory tops.
  docker run -it --kernel-memory 50M ubuntu:24.04 /bin/bash
  We set kernel memory without
  , so the processes in the container can
  use as much memory as they want, but they can only use 50M kernel memory.
  Swappiness constraint
  By default, a container's kernel can swap out a percentage of anonymous pages.
  To set this percentage for a container, specify a
  --memory-swappiness
  value
  between 0 and 100. A value of 0 turns off anonymous page swapping. A value of
  100 sets all anonymous pages as swappable. By default, if you are not using
  --memory-swappiness
  , memory swappiness value will be inherited from the parent.
  For example, you can set:
  docker run -it --memory-swappiness
  ubuntu:24.04 /bin/bash
  Setting the
  --memory-swappiness
  option is helpful when you want to retain the
  container's working set and to avoid swapping performance penalties.
  CPU share constraint
  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. If 0 is set, the system will ignore the
  value and use the default of 1024.
  The proportion will only apply when CPU-intensive processes are running.
  When tasks in one container are idle, other containers can use the
  left-over CPU time. The actual amount of CPU time will vary depending on
  the number of containers running on the system.
  For example, consider three containers, one has a cpu-share of 1024 and
  two others have a cpu-share setting of 512. When processes in all three
  containers attempt to use 100% of CPU, the first container would receive
  50% of the total CPU time. If you add a fourth container with a cpu-share
  of 1024, the first container only gets 33% of the CPU. The remaining containers
  receive 16.5%, 16.5% and 33% of the CPU.
  On a multi-core system, the shares of CPU time are distributed over all CPU
  cores. Even if a container is limited to less than 100% of CPU time, it can
  use 100% of each individual CPU core.
  For example, consider a system with more than three cores. If you start one
  container
  {C0}
  with
  -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
  CPU period constraint
  The default CPU CFS (Completely Fair Scheduler) period is 100ms. We can use
  --cpu-period
  to set the period of CPUs to limit the container's CPU usage.
  And usually
  --cpu-period
  should work with
  --cpu-quota
  Examples:
  docker run -it --cpu-period
  --cpu-quota
  ubuntu:24.04 /bin/bash
  If there is 1 CPU, this means the container can get 50% CPU worth of run-time every 50ms.
  In addition to use
  --cpu-period
  --cpu-quota
  for setting CPU period constraints,
  it is possible to specify
  --cpus
  with a float number to achieve the same purpose.
  For example, if there is 1 CPU, then
  --cpus=0.5
  will achieve the same result as
  setting
  --cpu-period=50000
  --cpu-quota=25000
  (50% CPU).
  The default value for
  --cpus
  , which means there is no limit.
  For more information, see the
  CFS documentation on bandwidth limiting
  Cpuset constraint
  We can set cpus in which to allow execution for containers.
  Examples:
  docker run -it --cpuset-cpus
  "1,3"
  ubuntu:24.04 /bin/bash
  This means processes in container can be executed on cpu 1 and cpu 3.
  docker run -it --cpuset-cpus
  "0-2"
  ubuntu:24.04 /bin/bash
  This means processes in container can be executed on cpu 0, cpu 1 and cpu 2.
  We can set mems in which to allow execution for containers. Only effective
  on NUMA systems.
  Examples:
  docker run -it --cpuset-mems
  "1,3"
  ubuntu:24.04 /bin/bash
  This example restricts the processes in the container to only use memory from
  memory nodes 1 and 3.
  docker run -it --cpuset-mems
  "0-2"
  ubuntu:24.04 /bin/bash
  This example restricts the processes in the container to only use memory from
  memory nodes 0, 1 and 2.
  CPU quota constraint
  --cpu-quota
  flag limits the container's CPU usage. The default 0 value
  allows the container to take 100% of a CPU resource (1 CPU). The CFS (Completely Fair
  Scheduler) handles resource allocation for executing processes and is default
  Linux Scheduler used by the kernel. Set this value to 50000 to limit the container
  to 50% of a CPU resource. For multiple CPUs, adjust the
  --cpu-quota
  as necessary.
  For more information, see the
  CFS documentation on bandwidth limiting
  Block IO bandwidth (Blkio) constraint
  By default, all containers get the same proportion of block IO bandwidth
  (blkio). This proportion is 500. To modify this proportion, change the
  container's blkio weight relative to the weighting of all other running
  containers using the
  --blkio-weight
  flag.
  Note
  The blkio weight setting is only available for direct IO. Buffered IO is not
  currently supported.
  --blkio-weight
  flag can set the weighting to a value between 10 to 1000.
  For example, the commands below create two containers with different blkio
  weight:
  docker run -it --name c1 --blkio-weight
  ubuntu:24.04 /bin/bash
  docker run -it --name c2 --blkio-weight
  ubuntu:24.04 /bin/bash
  If you do block IO in the two containers at the same time, by, for example:
  time
  /mnt/zerofile
  test.out
  count
  oflag
  direct
  You'll find that the proportion of time is the same as the proportion of blkio
  weights of the two containers.
  --blkio-weight-device="DEVICE_NAME:WEIGHT"
  flag sets a specific device weight.
  DEVICE_NAME:WEIGHT
  is a string containing a colon-separated device name and weight.
  For example, to set
  /dev/sda
  device weight to
  docker run -it
  --blkio-weight-device "/dev/sda:200" \
  ubuntu
  If you specify both the
  --blkio-weight
  --blkio-weight-device
  , Docker
  uses the
  --blkio-weight
  as the default weight and uses
  --blkio-weight-device
  to override this default with a new value on a specific device.
  The following example uses a default weight of
  and overrides this default
  /dev/sda
  setting that weight to
  docker run -it
  --blkio-weight 300 \
  --blkio-weight-device "/dev/sda:200" \
  ubuntu
  --device-read-bps
  flag limits the read rate (bytes per second) from a device.
  For example, this command creates a container and limits the read rate to
  per second from
  /dev/sda
  docker run -it --device-read-bps /dev/sda:1mb ubuntu
  --device-write-bps
  flag limits the write rate (bytes per second) to a device.
  For example, this command creates a container and limits the write rate to
  per second for
  /dev/sda
  docker run -it --device-write-bps /dev/sda:1mb ubuntu
  Both flags take limits in the
  <device-path>:<limit>[unit]
  format. Both read
  and write rates must be a positive integer. You can specify the rate in
  (kilobytes),
  (megabytes), or
  (gigabytes).
  --device-read-iops
  flag limits read rate (IO per second) from a device.
  For example, this command creates a container and limits the read rate to
  IO per second from
  /dev/sda
  docker run -it --device-read-iops /dev/sda:1000 ubuntu
  --device-write-iops
  flag limits write rate (IO per second) to a device.
  For example, this command creates a container and limits the write rate to
  IO per second to
  /dev/sda
  docker run -it --device-write-iops /dev/sda:1000 ubuntu
  Both flags take limits in the
  <device-path>:<limit>
  format. Both read and
  write rates must be a positive integer.
  Additional groups
  --group-add: Add additional groups to run as
  By default, the docker container process runs with the supplementary groups looked
  up for the specified user. If one wants to add more to that list of groups, then
  one can use this flag:
  docker run --rm --group-add audio --group-add nogroup --group-add
  busybox id
  uid=0(root) gid=0(root) groups=10(wheel),29(audio),99(nogroup),777
  Runtime privilege and Linux capabilities
  Option
  Description
  --cap-add
  Add Linux capabilities
  --cap-drop
  Drop Linux capabilities
  --privileged
  Give extended privileges to this container
  --device=[]
  Allows you to run devices inside the container without the
  --privileged
  flag.
  By default, Docker containers are "unprivileged" and cannot, for
  example, run a Docker daemon inside a Docker container. This is because
  by default a container is not allowed to access any devices, but a
  "privileged" container is given access to all devices (see
  the documentation on
  cgroups devices
  --privileged
  flag gives all capabilities to the container. When the operator
  executes
  docker run --privileged
  , Docker enables access to all devices on
  the host, and reconfigures AppArmor or SELinux to allow the container
  nearly all the same access to the host as processes running outside
  containers on the host. Use this flag with caution.
  For more information about the
  --privileged
  flag, see the
  docker run
  If you want to limit access to a specific device or devices you can use
  --device
  flag. It allows you to specify one or more devices that
  will be accessible within the container.
  docker run --device
  /dev/snd:/dev/snd ...
  By default, the container will be able to
  read
  write
  , and
  mknod
  these devices.
  This can be overridden using a third
  :rwm
  set of options to each
  --device
  flag:
  docker run --device
  /dev/sda:/dev/xvdc --rm -it ubuntu fdisk /dev/xvdc
  Command (m for help): q
  docker run --device
  /dev/sda:/dev/xvdc:r --rm -it ubuntu fdisk /dev/xvdc
  You will not be able to write the partition table.
  Command (m for help): q
  docker run --device
  /dev/sda:/dev/xvdc:w --rm -it ubuntu fdisk /dev/xvdc
  crash....
  docker run --device
  /dev/sda:/dev/xvdc:m --rm -it ubuntu fdisk /dev/xvdc
  fdisk: unable to open /dev/xvdc: Operation not permitted
  In addition to
  --privileged
  , the operator can have fine grain control over the
  capabilities using
  --cap-add
  --cap-drop
  . By default, Docker has a default
  list of capabilities that are kept. The following table lists the Linux capability
  options which are allowed by default and can be dropped.
  Capability Key
  Capability Description
  AUDIT_WRITE
  Write records to kernel auditing log.
  CHOWN
  Make arbitrary changes to file UIDs and GIDs (see chown(2)).
  DAC_OVERRIDE
  Bypass file read, write, and execute permission checks.
  FOWNER
  Bypass permission checks on operations that normally require the file system UID of the process to match the UID of the file.
  FSETID
  Don't clear set-user-ID and set-group-ID permission bits when a file is modified.
  KILL
  Bypass permission checks for sending signals.
  MKNOD
  Create special files using mknod(2).
  NET_BIND_SERVICE
  Bind a socket to internet domain privileged ports (port numbers less than 1024).
  NET_RAW
  Use RAW and PACKET sockets.
  SETFCAP
  Set file capabilities.
  SETGID
  Make arbitrary manipulations of process GIDs and supplementary GID list.
  SETPCAP
  Modify process capabilities.
  SETUID
  Make arbitrary manipulations of process UIDs.
  SYS_CHROOT
  Use chroot(2), change root directory.
  The next table shows the capabilities which are not granted by default and may be added.
  Capability Key
  Capability Description
  AUDIT_CONTROL
  Enable and disable kernel auditing; change auditing filter rules; retrieve auditing status and filtering rules.
  AUDIT_READ
  Allow reading the audit log via multicast netlink socket.
  BLOCK_SUSPEND
  Allow preventing system suspends.
  Allow creating BPF maps, loading BPF Type Format (BTF) data, retrieve JITed code of BPF programs, and more.
  CHECKPOINT_RESTORE
  Allow checkpoint/restore related operations. Introduced in kernel 5.9.
  DAC_READ_SEARCH
  Bypass file read permission checks and directory read and execute permission checks.
  IPC_LOCK
  Lock memory (mlock(2), mlockall(2), mmap(2), shmctl(2)).
  IPC_OWNER
  Bypass permission checks for operations on System V IPC objects.
  LEASE
  Establish leases on arbitrary files (see fcntl(2)).
  LINUX_IMMUTABLE
  Set the FS_APPEND_FL and FS_IMMUTABLE_FL i-node flags.
  MAC_ADMIN
  Allow MAC configuration or state changes. Implemented for the Smack LSM.
  MAC_OVERRIDE
  Override Mandatory Access Control (MAC). Implemented for the Smack Linux Security Module (LSM).
  NET_ADMIN
  Perform various network-related operations.
  NET_BROADCAST
  Make socket broadcasts, and listen to multicasts.
  PERFMON
  Allow system performance and observability privileged operations using perf_events, i915_perf and other kernel subsystems
  SYS_ADMIN
  Perform a range of system administration operations.
  SYS_BOOT
  Use reboot(2) and kexec_load(2), reboot and load a new kernel for later execution.
  SYS_MODULE
  Load and unload kernel modules.
  SYS_NICE
  Raise process nice value (nice(2), setpriority(2)) and change the nice value for arbitrary processes.
  SYS_PACCT
  Use acct(2), switch process accounting on or off.
  SYS_PTRACE
  Trace arbitrary processes using ptrace(2).
  SYS_RAWIO
  Perform I/O port operations (iopl(2) and ioperm(2)).
  SYS_RESOURCE
  Override resource Limits.
  SYS_TIME
  Set system clock (settimeofday(2), stime(2), adjtimex(2)); set real-time (hardware) clock.
  SYS_TTY_CONFIG
  Use vhangup(2); employ various privileged ioctl(2) operations on virtual terminals.
  SYSLOG
  Perform privileged syslog(2) operations.
  WAKE_ALARM
  Trigger something that will wake up the system.
  Further reference information is available on the
  capabilities(7) - Linux man page
  and in the
  Linux kernel source code
  Both flags support the value
  , so to allow a container to use all capabilities
  except for
  MKNOD
  docker run --cap-add
  ALL --cap-drop
  MKNOD ...
  --cap-add
  --cap-drop
  flags accept capabilities to be specified with
  CAP_
  prefix. The following examples are therefore equivalent:
  docker run --cap-add
  SYS_ADMIN ...
  docker run --cap-add
  CAP_SYS_ADMIN ...
  For interacting with the network stack, instead of using
  --privileged
  they
  should use
  --cap-add=NET_ADMIN
  to modify the network interfaces.
  docker run -it --rm ubuntu:24.04 ip link add dummy0
  type
  dummy
  RTNETLINK answers: Operation not permitted
  docker run -it --rm --cap-add
  NET_ADMIN ubuntu:24.04 ip link add dummy0
  type
  dummy
  To mount a FUSE based filesystem, you need to combine both
  --cap-add
  --device
  docker run --rm -it --cap-add SYS_ADMIN sshfs sshfs sven@10.10.10.20:/home/sven /mnt
  fuse: failed to open /dev/fuse: Operation not permitted
  docker run --rm -it --device /dev/fuse sshfs sshfs sven@10.10.10.20:/home/sven /mnt
  fusermount: mount failed: Operation not permitted
  docker run --rm -it --cap-add SYS_ADMIN --device /dev/fuse sshfs
  sshfs sven@10.10.10.20:/home/sven /mnt
  The authenticity of host '10.10.10.20 (10.10.10.20)' can't be established.
  ECDSA key fingerprint is 25:34:85:75:25:b0:17:46:05:19:04:93:b5:dd:5f:c6.
  Are you sure you want to continue connecting (yes/no)? yes
  sven@10.10.10.20's password:
  root@30aa0cfaf1b5:/# ls -la /mnt/src/docker
  total 1516
  drwxrwxr-x 1 1000 1000 4096 Dec 4 06:08 .
  drwxrwxr-x 1 1000 1000 4096 Dec 4 11:46 ..
  -rw-rw-r-- 1 1000 1000 16 Oct 8 00:09 .dockerignore
  -rwxrwxr-x 1 1000 1000 464 Oct 8 00:09 .drone.yml
  drwxrwxr-x 1 1000 1000 4096 Dec 4 06:11 .git
  -rw-rw-r-- 1 1000 1000 461 Dec 4 06:08 .gitignore
  The default seccomp profile will adjust to the selected capabilities, in order to allow
  use of facilities allowed by the capabilities, so you should not have to adjust this.
  Overriding image defaults
  When you build an image from a
  Dockerfile
  or when committing it, you can set a number of default parameters that take
  effect when the image starts up as a container. When you run an image, you can
  override those defaults using flags for the
  docker run
  command.
  Default entrypoint
  Default command and options
  Expose ports
  Environment variables
  Healthcheck
  User
  Working directory
  Default command and options
  The command syntax for
  docker run
  supports optionally specifying commands and
  arguments to the container's entrypoint, represented as
  [COMMAND]
  [ARG...]
  in the following synopsis example:
  docker run
  OPTIONS
  IMAGE
  :TAG
  @DIGEST
  COMMAND
  ARG...
  This command is optional because whoever created the
  IMAGE
  may have already
  provided a default
  COMMAND
  , using the Dockerfile
  instruction. When you
  run a container, you can override that
  instruction just by specifying a
  COMMAND
  If the image also specifies an
  ENTRYPOINT
  then the
  COMMAND
  get appended as arguments to the
  ENTRYPOINT
  Default entrypoint
  --entrypoint="": Overwrite the default entrypoint set by the image
  The entrypoint refers to the default executable that's invoked when you run a
  container. A container's entrypoint is defined using the Dockerfile
  ENTRYPOINT
  instruction. It's similar to specifying a default command because
  it specifies, but the difference is that you need to pass an explicit flag to
  override the entrypoint, whereas you can override default commands with
  positional arguments. The defines a container's default behavior, with the idea
  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 as
  commands. But there are cases where you may want to run something else inside
  the container. This is when overriding the default entrypoint at runtime comes
  in handy, using the
  --entrypoint
  flag for the
  docker run
  command.
  --entrypoint
  flag expects a string value, representing the name or path
  of the binary that you want to invoke when the container starts. The following
  example shows you how to run a Bash shell in a container that has been set up
  to automatically run some other binary (like
  /usr/bin/redis-server
  docker run -it --entrypoint /bin/bash example/redis
  The following examples show how to pass additional parameters to the custom
  entrypoint, using the positional command arguments:
  docker run -it --entrypoint /bin/bash example/redis -c ls -l
  docker run -it --entrypoint /usr/bin/redis-cli example/redis --help
  You can reset a containers entrypoint by passing an empty string, for example:
  docker run -it --entrypoint
  mysql bash
  Note
  Passing
  --entrypoint
  clears out any default command set on the image. That
  is, any
  instruction in the Dockerfile used to build it.
  Exposed ports
  By default, when you run a container, none of the container's ports are exposed
  to the host. This means you won't be able to access any ports that the
  container might be listening on. To make a container's ports accessible from
  the host, you need to publish the ports.
  You can start the container with the
  flags to expose its ports:
  --publish-all
  ) flag publishes all the exposed ports to the
  host. Docker binds each exposed port to a random port on the host.
  flag only publishes port numbers that are explicitly flagged as
  exposed, either using the Dockerfile
  EXPOSE
  instruction or the
  --expose
  flag for the
  docker run
  command.
  --publish
  ) flag lets you explicitly map a single port or range
  of ports in the container to the host.
  The port number inside the container (where the service listens) doesn't need
  to match the port number published on the outside of the container (where
  clients connect). For example, inside the container an HTTP service might be
  listening on port 80. At runtime, the port might be bound to 42800 on the host.
  To find the mapping between the host ports and the exposed ports, use the
  docker port
  command.
  Environment variables
  Docker automatically sets some environment variables when creating a Linux
  container. Docker doesn't set any environment variables when creating a Windows
  container.
  The following environment variables are set for Linux containers:
  Variable
  Value
  Set based on the value of
  USER
  HOSTNAME
  The hostname associated with the container
  PATH
  Includes popular directories, such as
  /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
  TERM
  xterm
  if the container is allocated a pseudo-TTY
  Additionally, you can set any environment variable in the container by using
  one or more
  flags. You can even override the variables mentioned above, or
  variables defined using a Dockerfile
  instruction when building the image.
  If the you name an environment variable without specifying a value, the current
  value of the named variable on the host is propagated into the container's
  environment:
  export
  today
  Wednesday
  docker run -e
  "deep=purple"
  -e today --rm alpine env
  PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
  HOSTNAME=d2219b854598
  deep=purple
  today=Wednesday
  HOME=/root
  docker
  "foo=bar"
  microsoft
  nanoserver
  ALLUSERSPROFILE
  ProgramData
  APPDATA
  Users
  ContainerAdministrator
  AppData
  Roaming
  CommonProgramFiles
  Program
  Files
  Common
  Files
  CommonProgramFiles
  Program
  Files
  Common
  Files
  CommonProgramW6432
  Program
  Files
  Common
  Files
  COMPUTERNAME
  C2FAEFCC8253
  ComSpec
  Windows
  system32
  LOCALAPPDATA
  Users
  ContainerAdministrator
  AppData
  Local
  NUMBER_OF_PROCESSORS
  Windows_NT
  Path
  Windows
  system32
  Windows
  Windows
  System32
  Wbem
  Windows
  System32
  WindowsPowerShell
  Users
  ContainerAdministrator
  AppData
  Local
  Microsoft
  WindowsApps
  PATHEXT
  PROCESSOR_ARCHITECTURE
  AMD64
  PROCESSOR_IDENTIFIER
  Intel64
  Family
  Model
  Stepping
  GenuineIntel
  PROCESSOR_LEVEL
  PROCESSOR_REVISION
  3e04
  ProgramData
  ProgramData
  ProgramFiles
  Program
  Files
  ProgramFiles
  Program
  Files
  ProgramW6432
  Program
  Files
  PROMPT
  $P$G
  PUBLIC
  Users
  Public
  SystemDrive
  SystemRoot
  Windows
  TEMP
  Users
  ContainerAdministrator
  AppData
  Local
  Temp
  Users
  ContainerAdministrator
  AppData
  Local
  Temp
  USERDOMAIN
  User
  Manager
  USERNAME
  ContainerAdministrator
  USERPROFILE
  Users
  ContainerAdministrator
  windir
  Windows
  Healthchecks
  The following flags for the
  docker run
  command let you control the parameters
  for container healthchecks:
  Option
  Description
  --health-cmd
  Command to run to check health
  --health-interval
  Time between running the check
  --health-retries
  Consecutive failures needed to report unhealthy
  --health-timeout
  Maximum time to allow one check to run
  --health-start-period
  Start period for the container to initialize before starting health-retries countdown
  --health-start-interval
  Time between running the check during the start period
  --no-healthcheck
  Disable any container-specified
  HEALTHCHECK
  Example:
  docker run --name
  test
  --health-cmd='stat /etc/passwd || exit 1' \
  --health-interval=2s \
  busybox sleep 1d
  sleep 2
  docker inspect --format
  '{{.State.Health.Status}}'
  test
  healthy
  docker
  exec
  test
  rm /etc/passwd
  sleep 2
  docker inspect --format
  '{{json .State.Health}}'
  test
  "Status": "unhealthy",
  "FailingStreak": 3,
  "Log": [
  "Start": "2016-05-25T17:22:04.635478668Z",
  "End": "2016-05-25T17:22:04.7272552Z",
  "ExitCode": 0,
  "Output": " File: /etc/passwd\n Size: 334 \tBlocks: 8 IO Block: 4096 regular file\nDevice: 32h/50d\tInode: 12 Links: 1\nAccess: (0664/-rw-rw-r--) Uid: ( 0/ root) Gid: ( 0/ root)\nAccess: 2015-12-05 22:05:32.000000000\nModify: 2015..."
  "Start": "2016-05-25T17:22:06.732900633Z",
  "End": "2016-05-25T17:22:06.822168935Z",
  "ExitCode": 0,
  "Output": " File: /etc/passwd\n Size: 334 \tBlocks: 8 IO Block: 4096 regular file\nDevice: 32h/50d\tInode: 12 Links: 1\nAccess: (0664/-rw-rw-r--) Uid: ( 0/ root) Gid: ( 0/ root)\nAccess: 2015-12-05 22:05:32.000000000\nModify: 2015..."
  "Start": "2016-05-25T17:22:08.823956535Z",
  "End": "2016-05-25T17:22:08.897359124Z",
  "ExitCode": 1,
  "Output": "stat: can't stat '/etc/passwd': No such file or directory\n"
  "Start": "2016-05-25T17:22:10.898802931Z",
  "End": "2016-05-25T17:22:10.969631866Z",
  "ExitCode": 1,
  "Output": "stat: can't stat '/etc/passwd': No such file or directory\n"
  "Start": "2016-05-25T17:22:12.971033523Z",
  "End": "2016-05-25T17:22:13.082015516Z",
  "ExitCode": 1,
  "Output": "stat: can't stat '/etc/passwd': No such file or directory\n"
  The health status is also displayed in the
  docker ps
  output.
  User
  The default user within a container is
  root
  (uid = 0). You can set a default
  user to run the first process with the Dockerfile
  USER
  instruction. When
  starting a container, you can override the
  USER
  instruction by passing the
  option.
  -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 ]
  Note
  If you pass a numeric user ID, it must be in the range of 0-2147483647. If
  you pass a username, the user must exist in the container.
  Working directory
  The default working directory for running binaries within a container is the
  root directory (
  ). The default working directory of an image is set using
  the Dockerfile
  WORKDIR
  command. You can override the default working
  directory for an image using the
  --workdir
  ) flag for the
  docker run
  command:
  $ docker run --rm -w /my/workdir alpine pwd
  /my/workdir
  If the directory doesn't already exist in the container, it's created.