github.com/ojongerius/docker@v1.11.2/man/docker-run.1.md (about) 1 % DOCKER(1) Docker User Manuals 2 % Docker Community 3 % JUNE 2014 4 # NAME 5 docker-run - Run a command in a new container 6 7 # SYNOPSIS 8 **docker run** 9 [**-a**|**--attach**[=*[]*]] 10 [**--add-host**[=*[]*]] 11 [**--blkio-weight**[=*[BLKIO-WEIGHT]*]] 12 [**--blkio-weight-device**[=*[]*]] 13 [**--cpu-shares**[=*0*]] 14 [**--cap-add**[=*[]*]] 15 [**--cap-drop**[=*[]*]] 16 [**--cgroup-parent**[=*CGROUP-PATH*]] 17 [**--cidfile**[=*CIDFILE*]] 18 [**--cpu-period**[=*0*]] 19 [**--cpu-quota**[=*0*]] 20 [**--cpuset-cpus**[=*CPUSET-CPUS*]] 21 [**--cpuset-mems**[=*CPUSET-MEMS*]] 22 [**-d**|**--detach**] 23 [**--detach-keys**[=*[]*]] 24 [**--device**[=*[]*]] 25 [**--device-read-bps**[=*[]*]] 26 [**--device-read-iops**[=*[]*]] 27 [**--device-write-bps**[=*[]*]] 28 [**--device-write-iops**[=*[]*]] 29 [**--dns**[=*[]*]] 30 [**--dns-opt**[=*[]*]] 31 [**--dns-search**[=*[]*]] 32 [**-e**|**--env**[=*[]*]] 33 [**--entrypoint**[=*ENTRYPOINT*]] 34 [**--env-file**[=*[]*]] 35 [**--expose**[=*[]*]] 36 [**--group-add**[=*[]*]] 37 [**-h**|**--hostname**[=*HOSTNAME*]] 38 [**--help**] 39 [**-i**|**--interactive**] 40 [**--ip**[=*IPv4-ADDRESS*]] 41 [**--ip6**[=*IPv6-ADDRESS*]] 42 [**--ipc**[=*IPC*]] 43 [**--isolation**[=*default*]] 44 [**--kernel-memory**[=*KERNEL-MEMORY*]] 45 [**-l**|**--label**[=*[]*]] 46 [**--label-file**[=*[]*]] 47 [**--link**[=*[]*]] 48 [**--log-driver**[=*[]*]] 49 [**--log-opt**[=*[]*]] 50 [**-m**|**--memory**[=*MEMORY*]] 51 [**--mac-address**[=*MAC-ADDRESS*]] 52 [**--memory-reservation**[=*MEMORY-RESERVATION*]] 53 [**--memory-swap**[=*LIMIT*]] 54 [**--memory-swappiness**[=*MEMORY-SWAPPINESS*]] 55 [**--name**[=*NAME*]] 56 [**--net**[=*"bridge"*]] 57 [**--net-alias**[=*[]*]] 58 [**--oom-kill-disable**] 59 [**--oom-score-adj**[=*0*]] 60 [**-P**|**--publish-all**] 61 [**-p**|**--publish**[=*[]*]] 62 [**--pid**[=*[]*]] 63 [**--userns**[=*[]*]] 64 [**--pids-limit**[=*PIDS_LIMIT*]] 65 [**--privileged**] 66 [**--read-only**] 67 [**--restart**[=*RESTART*]] 68 [**--rm**] 69 [**--security-opt**[=*[]*]] 70 [**--stop-signal**[=*SIGNAL*]] 71 [**--shm-size**[=*[]*]] 72 [**--sig-proxy**[=*true*]] 73 [**-t**|**--tty**] 74 [**--tmpfs**[=*[CONTAINER-DIR[:<OPTIONS>]*]] 75 [**-u**|**--user**[=*USER*]] 76 [**--ulimit**[=*[]*]] 77 [**--uts**[=*[]*]] 78 [**-v**|**--volume**[=*[[HOST-DIR:]CONTAINER-DIR[:OPTIONS]]*]] 79 [**--volume-driver**[=*DRIVER*]] 80 [**--volumes-from**[=*[]*]] 81 [**-w**|**--workdir**[=*WORKDIR*]] 82 IMAGE [COMMAND] [ARG...] 83 84 # DESCRIPTION 85 86 Run a process in a new container. **docker run** starts a process with its own 87 file system, its own networking, and its own isolated process tree. The IMAGE 88 which starts the process may define defaults related to the process that will be 89 run in the container, the networking to expose, and more, but **docker run** 90 gives final control to the operator or administrator who starts the container 91 from the image. For that reason **docker run** has more options than any other 92 Docker command. 93 94 If the IMAGE is not already loaded then **docker run** will pull the IMAGE, and 95 all image dependencies, from the repository in the same way running **docker 96 pull** IMAGE, before it starts the container from that image. 97 98 # OPTIONS 99 **-a**, **--attach**=[] 100 Attach to STDIN, STDOUT or STDERR. 101 102 In foreground mode (the default when **-d** 103 is not specified), **docker run** can start the process in the container 104 and attach the console to the process’s standard input, output, and standard 105 error. It can even pretend to be a TTY (this is what most commandline 106 executables expect) and pass along signals. The **-a** option can be set for 107 each of stdin, stdout, and stderr. 108 109 **--add-host**=[] 110 Add a custom host-to-IP mapping (host:ip) 111 112 Add a line to /etc/hosts. The format is hostname:ip. The **--add-host** 113 option can be set multiple times. 114 115 **--blkio-weight**=*0* 116 Block IO weight (relative weight) accepts a weight value between 10 and 1000. 117 118 **--blkio-weight-device**=[] 119 Block IO weight (relative device weight, format: `DEVICE_NAME:WEIGHT`). 120 121 **--cpu-shares**=*0* 122 CPU shares (relative weight) 123 124 By default, all containers get the same proportion of CPU cycles. This proportion 125 can be modified by changing the container's CPU share weighting relative 126 to the weighting of all other running containers. 127 128 To modify the proportion from the default of 1024, use the **--cpu-shares** 129 flag to set the weighting to 2 or higher. 130 131 The proportion will only apply when CPU-intensive processes are running. 132 When tasks in one container are idle, other containers can use the 133 left-over CPU time. The actual amount of CPU time will vary depending on 134 the number of containers running on the system. 135 136 For example, consider three containers, one has a cpu-share of 1024 and 137 two others have a cpu-share setting of 512. When processes in all three 138 containers attempt to use 100% of CPU, the first container would receive 139 50% of the total CPU time. If you add a fourth container with a cpu-share 140 of 1024, the first container only gets 33% of the CPU. The remaining containers 141 receive 16.5%, 16.5% and 33% of the CPU. 142 143 On a multi-core system, the shares of CPU time are distributed over all CPU 144 cores. Even if a container is limited to less than 100% of CPU time, it can 145 use 100% of each individual CPU core. 146 147 For example, consider a system with more than three cores. If you start one 148 container **{C0}** with **-c=512** running one process, and another container 149 **{C1}** with **-c=1024** running two processes, this can result in the following 150 division of CPU shares: 151 152 PID container CPU CPU share 153 100 {C0} 0 100% of CPU0 154 101 {C1} 1 100% of CPU1 155 102 {C1} 2 100% of CPU2 156 157 **--cap-add**=[] 158 Add Linux capabilities 159 160 **--cap-drop**=[] 161 Drop Linux capabilities 162 163 **--cgroup-parent**="" 164 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. 165 166 **--cidfile**="" 167 Write the container ID to the file 168 169 **--cpu-period**=*0* 170 Limit the CPU CFS (Completely Fair Scheduler) period 171 172 Limit the container's CPU usage. This flag tell the kernel to restrict the container's CPU usage to the period you specify. 173 174 **--cpuset-cpus**="" 175 CPUs in which to allow execution (0-3, 0,1) 176 177 **--cpuset-mems**="" 178 Memory nodes (MEMs) in which to allow execution (0-3, 0,1). Only effective on NUMA systems. 179 180 If you have four memory nodes on your system (0-3), use `--cpuset-mems=0,1` 181 then processes in your Docker container will only use memory from the first 182 two memory nodes. 183 184 **--cpu-quota**=*0* 185 Limit the CPU CFS (Completely Fair Scheduler) quota 186 187 Limit the container's CPU usage. By default, containers run with the full 188 CPU resource. This flag tell the kernel to restrict the container's CPU usage 189 to the quota you specify. 190 191 **-d**, **--detach**=*true*|*false* 192 Detached mode: run the container in the background and print the new container ID. The default is *false*. 193 194 At any time you can run **docker ps** in 195 the other shell to view a list of the running containers. You can reattach to a 196 detached container with **docker attach**. If you choose to run a container in 197 the detached mode, then you cannot use the **-rm** option. 198 199 When attached in the tty mode, you can detach from the container (and leave it 200 running) using a configurable key sequence. The default sequence is `CTRL-p CTRL-q`. 201 You configure the key sequence using the **--detach-keys** option or a configuration file. 202 See **config-json(5)** for documentation on using a configuration file. 203 204 **--detach-keys**="" 205 Override the key sequence for detaching a container. Format is a single character `[a-Z]` or `ctrl-<value>` where `<value>` is one of: `a-z`, `@`, `^`, `[`, `,` or `_`. 206 207 **--device**=[] 208 Add a host device to the container (e.g. --device=/dev/sdc:/dev/xvdc:rwm) 209 210 **--device-read-bps**=[] 211 Limit read rate from a device (e.g. --device-read-bps=/dev/sda:1mb) 212 213 **--device-read-iops**=[] 214 Limit read rate from a device (e.g. --device-read-iops=/dev/sda:1000) 215 216 **--device-write-bps**=[] 217 Limit write rate to a device (e.g. --device-write-bps=/dev/sda:1mb) 218 219 **--device-write-iops**=[] 220 Limit write rate a a device (e.g. --device-write-iops=/dev/sda:1000) 221 222 **--dns-search**=[] 223 Set custom DNS search domains (Use --dns-search=. if you don't wish to set the search domain) 224 225 **--dns-opt**=[] 226 Set custom DNS options 227 228 **--dns**=[] 229 Set custom DNS servers 230 231 This option can be used to override the DNS 232 configuration passed to the container. Typically this is necessary when the 233 host DNS configuration is invalid for the container (e.g., 127.0.0.1). When this 234 is the case the **--dns** flags is necessary for every run. 235 236 **-e**, **--env**=[] 237 Set environment variables 238 239 This option allows you to specify arbitrary 240 environment variables that are available for the process that will be launched 241 inside of the container. 242 243 **--entrypoint**="" 244 Overwrite the default ENTRYPOINT of the image 245 246 This option allows you to overwrite the default entrypoint of the image that 247 is set in the Dockerfile. The ENTRYPOINT of an image is similar to a COMMAND 248 because it specifies what executable to run when the container starts, but it is 249 (purposely) more difficult to override. The ENTRYPOINT gives a container its 250 default nature or behavior, so that when you set an ENTRYPOINT you can run the 251 container as if it were that binary, complete with default options, and you can 252 pass in more options via the COMMAND. But, sometimes an operator may want to run 253 something else inside the container, so you can override the default ENTRYPOINT 254 at runtime by using a **--entrypoint** and a string to specify the new 255 ENTRYPOINT. 256 257 **--env-file**=[] 258 Read in a line delimited file of environment variables 259 260 **--expose**=[] 261 Expose a port, or a range of ports (e.g. --expose=3300-3310) informs Docker 262 that the container listens on the specified network ports at runtime. Docker 263 uses this information to interconnect containers using links and to set up port 264 redirection on the host system. 265 266 **--group-add**=[] 267 Add additional groups to run as 268 269 **-h**, **--hostname**="" 270 Container host name 271 272 Sets the container host name that is available inside the container. 273 274 **--help** 275 Print usage statement 276 277 **-i**, **--interactive**=*true*|*false* 278 Keep STDIN open even if not attached. The default is *false*. 279 280 When set to true, keep stdin open even if not attached. The default is false. 281 282 **--ip**="" 283 Sets the container's interface IPv4 address (e.g. 172.23.0.9) 284 285 It can only be used in conjunction with **--net** for user-defined networks 286 287 **--ip6**="" 288 Sets the container's interface IPv6 address (e.g. 2001:db8::1b99) 289 290 It can only be used in conjunction with **--net** for user-defined networks 291 292 **--ipc**="" 293 Default is to create a private IPC namespace (POSIX SysV IPC) for the container 294 'container:<name|id>': reuses another container shared memory, semaphores and message queues 295 'host': use the host shared memory,semaphores and message queues inside the container. Note: the host mode gives the container full access to local shared memory and is therefore considered insecure. 296 297 **--isolation**="*default*" 298 Isolation specifies the type of isolation technology used by containers. 299 300 **-l**, **--label**=[] 301 Set metadata on the container (e.g., --label com.example.key=value) 302 303 **--kernel-memory**="" 304 Kernel memory limit (format: `<number>[<unit>]`, where unit = b, k, m or g) 305 306 Constrains the kernel memory available to a container. If a limit of 0 307 is specified (not using `--kernel-memory`), the container's kernel memory 308 is not limited. If you specify a limit, it may be rounded up to a multiple 309 of the operating system's page size and the value can be very large, 310 millions of trillions. 311 312 **--label-file**=[] 313 Read in a line delimited file of labels 314 315 **--link**=[] 316 Add link to another container in the form of <name or id>:alias or just <name or id> 317 in which case the alias will match the name 318 319 If the operator 320 uses **--link** when starting the new client container, then the client 321 container can access the exposed port via a private networking interface. Docker 322 will set some environment variables in the client container to help indicate 323 which interface and port to use. 324 325 **--log-driver**="*json-file*|*syslog*|*journald*|*gelf*|*fluentd*|*awslogs*|*splunk*|*etwlogs*|*gcplogs*|*none*" 326 Logging driver for container. Default is defined by daemon `--log-driver` flag. 327 **Warning**: the `docker logs` command works only for the `json-file` and 328 `journald` logging drivers. 329 330 **--log-opt**=[] 331 Logging driver specific options. 332 333 **-m**, **--memory**="" 334 Memory limit (format: <number>[<unit>], where unit = b, k, m or g) 335 336 Allows you to constrain the memory available to a container. If the host 337 supports swap memory, then the **-m** memory setting can be larger than physical 338 RAM. If a limit of 0 is specified (not using **-m**), the container's memory is 339 not limited. The actual limit may be rounded up to a multiple of the operating 340 system's page size (the value would be very large, that's millions of trillions). 341 342 **--memory-reservation**="" 343 Memory soft limit (format: <number>[<unit>], where unit = b, k, m or g) 344 345 After setting memory reservation, when the system detects memory contention 346 or low memory, containers are forced to restrict their consumption to their 347 reservation. So you should always set the value below **--memory**, otherwise the 348 hard limit will take precedence. By default, memory reservation will be the same 349 as memory limit. 350 351 **--memory-swap**="LIMIT" 352 A limit value equal to memory plus swap. Must be used with the **-m** 353 (**--memory**) flag. The swap `LIMIT` should always be larger than **-m** 354 (**--memory**) value. 355 356 The format of `LIMIT` is `<number>[<unit>]`. Unit can be `b` (bytes), 357 `k` (kilobytes), `m` (megabytes), or `g` (gigabytes). If you don't specify a 358 unit, `b` is used. Set LIMIT to `-1` to enable unlimited swap. 359 360 **--mac-address**="" 361 Container MAC address (e.g. 92:d0:c6:0a:29:33) 362 363 Remember that the MAC address in an Ethernet network must be unique. 364 The IPv6 link-local address will be based on the device's MAC address 365 according to RFC4862. 366 367 **--name**="" 368 Assign a name to the container 369 370 The operator can identify a container in three ways: 371 UUID long identifier (“f78375b1c487e03c9438c729345e54db9d20cfa2ac1fc3494b6eb60872e74778”) 372 UUID short identifier (“f78375b1c487”) 373 Name (“jonah”) 374 375 The UUID identifiers come from the Docker daemon, and if a name is not assigned 376 to the container with **--name** then the daemon will also generate a random 377 string name. The name is useful when defining links (see **--link**) (or any 378 other place you need to identify a container). This works for both background 379 and foreground Docker containers. 380 381 **--net**="*bridge*" 382 Set the Network mode for the container 383 'bridge': create a network stack on the default Docker bridge 384 'none': no networking 385 'container:<name|id>': reuse another container's network stack 386 'host': use the Docker host network stack. Note: the host mode gives the container full access to local system services such as D-bus and is therefore considered insecure. 387 '<network-name>|<network-id>': connect to a user-defined network 388 389 **--net-alias**=[] 390 Add network-scoped alias for the container 391 392 **--oom-kill-disable**=*true*|*false* 393 Whether to disable OOM Killer for the container or not. 394 395 **--oom-score-adj**="" 396 Tune the host's OOM preferences for containers (accepts -1000 to 1000) 397 398 **-P**, **--publish-all**=*true*|*false* 399 Publish all exposed ports to random ports on the host interfaces. The default is *false*. 400 401 When set to true publish all exposed ports to the host interfaces. The 402 default is false. If the operator uses -P (or -p) then Docker will make the 403 exposed port accessible on the host and the ports will be available to any 404 client that can reach the host. When using -P, Docker will bind any exposed 405 port to a random port on the host within an *ephemeral port range* defined by 406 `/proc/sys/net/ipv4/ip_local_port_range`. To find the mapping between the host 407 ports and the exposed ports, use `docker port`. 408 409 **-p**, **--publish**=[] 410 Publish a container's port, or range of ports, to the host. 411 412 Format: `ip:hostPort:containerPort | ip::containerPort | hostPort:containerPort | containerPort` 413 Both hostPort and containerPort can be specified as a range of ports. 414 When specifying ranges for both, the number of container ports in the range must match the number of host ports in the range. 415 (e.g., `docker run -p 1234-1236:1222-1224 --name thisWorks -t busybox` 416 but not `docker run -p 1230-1236:1230-1240 --name RangeContainerPortsBiggerThanRangeHostPorts -t busybox`) 417 With ip: `docker run -p 127.0.0.1:$HOSTPORT:$CONTAINERPORT --name CONTAINER -t someimage` 418 Use `docker port` to see the actual mapping: `docker port CONTAINER $CONTAINERPORT` 419 420 **--pid**=*host* 421 Set the PID mode for the container 422 **host**: use the host's PID namespace inside the container. 423 Note: the host mode gives the container full access to local PID and is therefore considered insecure. 424 425 **--userns**="" 426 Set the usernamespace mode for the container when `userns-remap` option is enabled. 427 **host**: use the host usernamespace and enable all privileged options (e.g., `pid=host` or `--privileged`). 428 429 **--pids-limit**="" 430 Tune the container's pids limit. Set `-1` to have unlimited pids for the container. 431 432 **--uts**=*host* 433 Set the UTS mode for the container 434 **host**: use the host's UTS namespace inside the container. 435 Note: the host mode gives the container access to changing the host's hostname and is therefore considered insecure. 436 437 **--privileged**=*true*|*false* 438 Give extended privileges to this container. The default is *false*. 439 440 By default, Docker containers are 441 “unprivileged” (=false) and cannot, for example, run a Docker daemon inside the 442 Docker container. This is because by default a container is not allowed to 443 access any devices. A “privileged” container is given access to all devices. 444 445 When the operator executes **docker run --privileged**, Docker will enable access 446 to all devices on the host as well as set some configuration in AppArmor to 447 allow the container nearly all the same access to the host as processes running 448 outside of a container on the host. 449 450 **--read-only**=*true*|*false* 451 Mount the container's root filesystem as read only. 452 453 By default a container will have its root filesystem writable allowing processes 454 to write files anywhere. By specifying the `--read-only` flag the container will have 455 its root filesystem mounted as read only prohibiting any writes. 456 457 **--restart**="*no*" 458 Restart policy to apply when a container exits (no, on-failure[:max-retry], always, unless-stopped). 459 460 **--rm**=*true*|*false* 461 Automatically remove the container when it exits (incompatible with -d). The default is *false*. 462 463 **--security-opt**=[] 464 Security Options 465 466 "label=user:USER" : Set the label user for the container 467 "label=role:ROLE" : Set the label role for the container 468 "label=type:TYPE" : Set the label type for the container 469 "label=level:LEVEL" : Set the label level for the container 470 "label=disable" : Turn off label confinement for the container 471 "no-new-privileges" : Disable container processes from gaining additional privileges 472 473 "seccomp=unconfined" : Turn off seccomp confinement for the container 474 "seccomp=profile.json : White listed syscalls seccomp Json file to be used as a seccomp filter 475 476 "apparmor=unconfined" : Turn off apparmor confinement for the container 477 "apparmor=your-profile" : Set the apparmor confinement profile for the container 478 479 **--stop-signal**=*SIGTERM* 480 Signal to stop a container. Default is SIGTERM. 481 482 **--shm-size**="" 483 Size of `/dev/shm`. The format is `<number><unit>`. 484 `number` must be greater than `0`. Unit is optional and can be `b` (bytes), `k` (kilobytes), `m`(megabytes), or `g` (gigabytes). 485 If you omit the unit, the system uses bytes. If you omit the size entirely, the system uses `64m`. 486 487 **--sig-proxy**=*true*|*false* 488 Proxy received signals to the process (non-TTY mode only). SIGCHLD, SIGSTOP, and SIGKILL are not proxied. The default is *true*. 489 490 **--memory-swappiness**="" 491 Tune a container's memory swappiness behavior. Accepts an integer between 0 and 100. 492 493 **-t**, **--tty**=*true*|*false* 494 Allocate a pseudo-TTY. The default is *false*. 495 496 When set to true Docker can allocate a pseudo-tty and attach to the standard 497 input of any container. This can be used, for example, to run a throwaway 498 interactive shell. The default is false. 499 500 The **-t** option is incompatible with a redirection of the docker client 501 standard input. 502 503 **--tmpfs**=[] Create a tmpfs mount 504 505 Mount a temporary filesystem (`tmpfs`) mount into a container, for example: 506 507 $ docker run -d --tmpfs /tmp:rw,size=787448k,mode=1777 my_image 508 509 This command mounts a `tmpfs` at `/tmp` within the container. The supported mount 510 options are the same as the Linux default `mount` flags. If you do not specify 511 any options, the systems uses the following options: 512 `rw,noexec,nosuid,nodev,size=65536k`. 513 514 **-u**, **--user**="" 515 Sets the username or UID used and optionally the groupname or GID for the specified command. 516 517 The followings examples are all valid: 518 --user [user | user:group | uid | uid:gid | user:gid | uid:group ] 519 520 Without this argument the command will be run as root in the container. 521 522 **--ulimit**=[] 523 Ulimit options 524 525 **-v**|**--volume**[=*[[HOST-DIR:]CONTAINER-DIR[:OPTIONS]]*] 526 Create a bind mount. If you specify, ` -v /HOST-DIR:/CONTAINER-DIR`, Docker 527 bind mounts `/HOST-DIR` in the host to `/CONTAINER-DIR` in the Docker 528 container. If 'HOST-DIR' is omitted, Docker automatically creates the new 529 volume on the host. The `OPTIONS` are a comma delimited list and can be: 530 531 * [rw|ro] 532 * [z|Z] 533 * [`[r]shared`|`[r]slave`|`[r]private`] 534 * [nocopy] 535 536 The `CONTAINER-DIR` must be an absolute path such as `/src/docs`. The `HOST-DIR` 537 can be an absolute path or a `name` value. A `name` value must start with an 538 alphanumeric character, followed by `a-z0-9`, `_` (underscore), `.` (period) or 539 `-` (hyphen). An absolute path starts with a `/` (forward slash). 540 541 If you supply a `HOST-DIR` that is an absolute path, Docker bind-mounts to the 542 path you specify. If you supply a `name`, Docker creates a named volume by that 543 `name`. For example, you can specify either `/foo` or `foo` for a `HOST-DIR` 544 value. If you supply the `/foo` value, Docker creates a bind-mount. If you 545 supply the `foo` specification, Docker creates a named volume. 546 547 You can specify multiple **-v** options to mount one or more mounts to a 548 container. To use these same mounts in other containers, specify the 549 **--volumes-from** option also. 550 551 You can add `:ro` or `:rw` suffix to a volume to mount it read-only or 552 read-write mode, respectively. By default, the volumes are mounted read-write. 553 See examples. 554 555 Labeling systems like SELinux require that proper labels are placed on volume 556 content mounted into a container. Without a label, the security system might 557 prevent the processes running inside the container from using the content. By 558 default, Docker does not change the labels set by the OS. 559 560 To change a label in the container context, you can add either of two suffixes 561 `:z` or `:Z` to the volume mount. These suffixes tell Docker to relabel file 562 objects on the shared volumes. The `z` option tells Docker that two containers 563 share the volume content. As a result, Docker labels the content with a shared 564 content label. Shared volume labels allow all containers to read/write content. 565 The `Z` option tells Docker to label the content with a private unshared label. 566 Only the current container can use a private volume. 567 568 By default bind mounted volumes are `private`. That means any mounts done 569 inside container will not be visible on host and vice-a-versa. One can change 570 this behavior by specifying a volume mount propagation property. Making a 571 volume `shared` mounts done under that volume inside container will be 572 visible on host and vice-a-versa. Making a volume `slave` enables only one 573 way mount propagation and that is mounts done on host under that volume 574 will be visible inside container but not the other way around. 575 576 To control mount propagation property of volume one can use `:[r]shared`, 577 `:[r]slave` or `:[r]private` propagation flag. Propagation property can 578 be specified only for bind mounted volumes and not for internal volumes or 579 named volumes. For mount propagation to work source mount point (mount point 580 where source dir is mounted on) has to have right propagation properties. For 581 shared volumes, source mount point has to be shared. And for slave volumes, 582 source mount has to be either shared or slave. 583 584 Use `df <source-dir>` to figure out the source mount and then use 585 `findmnt -o TARGET,PROPAGATION <source-mount-dir>` to figure out propagation 586 properties of source mount. If `findmnt` utility is not available, then one 587 can look at mount entry for source mount point in `/proc/self/mountinfo`. Look 588 at `optional fields` and see if any propagaion properties are specified. 589 `shared:X` means mount is `shared`, `master:X` means mount is `slave` and if 590 nothing is there that means mount is `private`. 591 592 To change propagation properties of a mount point use `mount` command. For 593 example, if one wants to bind mount source directory `/foo` one can do 594 `mount --bind /foo /foo` and `mount --make-private --make-shared /foo`. This 595 will convert /foo into a `shared` mount point. Alternatively one can directly 596 change propagation properties of source mount. Say `/` is source mount for 597 `/foo`, then use `mount --make-shared /` to convert `/` into a `shared` mount. 598 599 > **Note**: 600 > When using systemd to manage the Docker daemon's start and stop, in the systemd 601 > unit file there is an option to control mount propagation for the Docker daemon 602 > itself, called `MountFlags`. The value of this setting may cause Docker to not 603 > see mount propagation changes made on the mount point. For example, if this value 604 > is `slave`, you may not be able to use the `shared` or `rshared` propagation on 605 > a volume. 606 607 To disable automatic copying of data from the container path to the volume, use 608 the `nocopy` flag. The `nocopy` flag can be set on bind mounts and named volumes. 609 610 **--volume-driver**="" 611 Container's volume driver. This driver creates volumes specified either from 612 a Dockerfile's `VOLUME` instruction or from the `docker run -v` flag. 613 See **docker-volume-create(1)** for full details. 614 615 **--volumes-from**=[] 616 Mount volumes from the specified container(s) 617 618 Mounts already mounted volumes from a source container onto another 619 container. You must supply the source's container-id. To share 620 a volume, use the **--volumes-from** option when running 621 the target container. You can share volumes even if the source container 622 is not running. 623 624 By default, Docker mounts the volumes in the same mode (read-write or 625 read-only) as it is mounted in the source container. Optionally, you 626 can change this by suffixing the container-id with either the `:ro` or 627 `:rw ` keyword. 628 629 If the location of the volume from the source container overlaps with 630 data residing on a target container, then the volume hides 631 that data on the target. 632 633 **-w**, **--workdir**="" 634 Working directory inside the container 635 636 The default working directory for 637 running binaries within a container is the root directory (/). The developer can 638 set a different default with the Dockerfile WORKDIR instruction. The operator 639 can override the working directory by using the **-w** option. 640 641 # Exit Status 642 643 The exit code from `docker run` gives information about why the container 644 failed to run or why it exited. When `docker run` exits with a non-zero code, 645 the exit codes follow the `chroot` standard, see below: 646 647 **_125_** if the error is with Docker daemon **_itself_** 648 649 $ docker run --foo busybox; echo $? 650 # flag provided but not defined: --foo 651 See 'docker run --help'. 652 125 653 654 **_126_** if the **_contained command_** cannot be invoked 655 656 $ docker run busybox /etc; echo $? 657 # exec: "/etc": permission denied 658 docker: Error response from daemon: Contained command could not be invoked 659 126 660 661 **_127_** if the **_contained command_** cannot be found 662 663 $ docker run busybox foo; echo $? 664 # exec: "foo": executable file not found in $PATH 665 docker: Error response from daemon: Contained command not found or does not exist 666 127 667 668 **_Exit code_** of **_contained command_** otherwise 669 670 $ docker run busybox /bin/sh -c 'exit 3' 671 # 3 672 673 # EXAMPLES 674 675 ## Running container in read-only mode 676 677 During container image development, containers often need to write to the image 678 content. Installing packages into /usr, for example. In production, 679 applications seldom need to write to the image. Container applications write 680 to volumes if they need to write to file systems at all. Applications can be 681 made more secure by running them in read-only mode using the --read-only switch. 682 This protects the containers image from modification. Read only containers may 683 still need to write temporary data. The best way to handle this is to mount 684 tmpfs directories on /run and /tmp. 685 686 # docker run --read-only --tmpfs /run --tmpfs /tmp -i -t fedora /bin/bash 687 688 ## Exposing log messages from the container to the host's log 689 690 If you want messages that are logged in your container to show up in the host's 691 syslog/journal then you should bind mount the /dev/log directory as follows. 692 693 # docker run -v /dev/log:/dev/log -i -t fedora /bin/bash 694 695 From inside the container you can test this by sending a message to the log. 696 697 (bash)# logger "Hello from my container" 698 699 Then exit and check the journal. 700 701 # exit 702 703 # journalctl -b | grep Hello 704 705 This should list the message sent to logger. 706 707 ## Attaching to one or more from STDIN, STDOUT, STDERR 708 709 If you do not specify -a then Docker will attach everything (stdin,stdout,stderr) 710 . You can specify to which of the three standard streams (stdin, stdout, stderr) 711 you’d like to connect instead, as in: 712 713 # docker run -a stdin -a stdout -i -t fedora /bin/bash 714 715 ## Sharing IPC between containers 716 717 Using shm_server.c available here: https://www.cs.cf.ac.uk/Dave/C/node27.html 718 719 Testing `--ipc=host` mode: 720 721 Host shows a shared memory segment with 7 pids attached, happens to be from httpd: 722 723 ``` 724 $ sudo ipcs -m 725 726 ------ Shared Memory Segments -------- 727 key shmid owner perms bytes nattch status 728 0x01128e25 0 root 600 1000 7 729 ``` 730 731 Now run a regular container, and it correctly does NOT see the shared memory segment from the host: 732 733 ``` 734 $ docker run -it shm ipcs -m 735 736 ------ Shared Memory Segments -------- 737 key shmid owner perms bytes nattch status 738 ``` 739 740 Run a container with the new `--ipc=host` option, and it now sees the shared memory segment from the host httpd: 741 742 ``` 743 $ docker run -it --ipc=host shm ipcs -m 744 745 ------ Shared Memory Segments -------- 746 key shmid owner perms bytes nattch status 747 0x01128e25 0 root 600 1000 7 748 ``` 749 Testing `--ipc=container:CONTAINERID` mode: 750 751 Start a container with a program to create a shared memory segment: 752 ``` 753 $ docker run -it shm bash 754 $ sudo shm/shm_server & 755 $ sudo ipcs -m 756 757 ------ Shared Memory Segments -------- 758 key shmid owner perms bytes nattch status 759 0x0000162e 0 root 666 27 1 760 ``` 761 Create a 2nd container correctly shows no shared memory segment from 1st container: 762 ``` 763 $ docker run shm ipcs -m 764 765 ------ Shared Memory Segments -------- 766 key shmid owner perms bytes nattch status 767 ``` 768 769 Create a 3rd container using the new --ipc=container:CONTAINERID option, now it shows the shared memory segment from the first: 770 771 ``` 772 $ docker run -it --ipc=container:ed735b2264ac shm ipcs -m 773 $ sudo ipcs -m 774 775 ------ Shared Memory Segments -------- 776 key shmid owner perms bytes nattch status 777 0x0000162e 0 root 666 27 1 778 ``` 779 780 ## Linking Containers 781 782 > **Note**: This section describes linking between containers on the 783 > default (bridge) network, also known as "legacy links". Using `--link` 784 > on user-defined networks uses the DNS-based discovery, which does not add 785 > entries to `/etc/hosts`, and does not set environment variables for 786 > discovery. 787 788 The link feature allows multiple containers to communicate with each other. For 789 example, a container whose Dockerfile has exposed port 80 can be run and named 790 as follows: 791 792 # docker run --name=link-test -d -i -t fedora/httpd 793 794 A second container, in this case called linker, can communicate with the httpd 795 container, named link-test, by running with the **--link=<name>:<alias>** 796 797 # docker run -t -i --link=link-test:lt --name=linker fedora /bin/bash 798 799 Now the container linker is linked to container link-test with the alias lt. 800 Running the **env** command in the linker container shows environment variables 801 with the LT (alias) context (**LT_**) 802 803 # env 804 HOSTNAME=668231cb0978 805 TERM=xterm 806 LT_PORT_80_TCP=tcp://172.17.0.3:80 807 LT_PORT_80_TCP_PORT=80 808 LT_PORT_80_TCP_PROTO=tcp 809 LT_PORT=tcp://172.17.0.3:80 810 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin 811 PWD=/ 812 LT_NAME=/linker/lt 813 SHLVL=1 814 HOME=/ 815 LT_PORT_80_TCP_ADDR=172.17.0.3 816 _=/usr/bin/env 817 818 When linking two containers Docker will use the exposed ports of the container 819 to create a secure tunnel for the parent to access. 820 821 If a container is connected to the default bridge network and `linked` 822 with other containers, then the container's `/etc/hosts` file is updated 823 with the linked container's name. 824 825 > **Note** Since Docker may live update the container’s `/etc/hosts` file, there 826 may be situations when processes inside the container can end up reading an 827 empty or incomplete `/etc/hosts` file. In most cases, retrying the read again 828 should fix the problem. 829 830 831 ## Mapping Ports for External Usage 832 833 The exposed port of an application can be mapped to a host port using the **-p** 834 flag. For example, a httpd port 80 can be mapped to the host port 8080 using the 835 following: 836 837 # docker run -p 8080:80 -d -i -t fedora/httpd 838 839 ## Creating and Mounting a Data Volume Container 840 841 Many applications require the sharing of persistent data across several 842 containers. Docker allows you to create a Data Volume Container that other 843 containers can mount from. For example, create a named container that contains 844 directories /var/volume1 and /tmp/volume2. The image will need to contain these 845 directories so a couple of RUN mkdir instructions might be required for you 846 fedora-data image: 847 848 # docker run --name=data -v /var/volume1 -v /tmp/volume2 -i -t fedora-data true 849 # docker run --volumes-from=data --name=fedora-container1 -i -t fedora bash 850 851 Multiple --volumes-from parameters will bring together multiple data volumes from 852 multiple containers. And it's possible to mount the volumes that came from the 853 DATA container in yet another container via the fedora-container1 intermediary 854 container, allowing to abstract the actual data source from users of that data: 855 856 # docker run --volumes-from=fedora-container1 --name=fedora-container2 -i -t fedora bash 857 858 ## Mounting External Volumes 859 860 To mount a host directory as a container volume, specify the absolute path to 861 the directory and the absolute path for the container directory separated by a 862 colon: 863 864 # docker run -v /var/db:/data1 -i -t fedora bash 865 866 When using SELinux, be aware that the host has no knowledge of container SELinux 867 policy. Therefore, in the above example, if SELinux policy is enforced, the 868 `/var/db` directory is not writable to the container. A "Permission Denied" 869 message will occur and an avc: message in the host's syslog. 870 871 872 To work around this, at time of writing this man page, the following command 873 needs to be run in order for the proper SELinux policy type label to be attached 874 to the host directory: 875 876 # chcon -Rt svirt_sandbox_file_t /var/db 877 878 879 Now, writing to the /data1 volume in the container will be allowed and the 880 changes will also be reflected on the host in /var/db. 881 882 ## Using alternative security labeling 883 884 You can override the default labeling scheme for each container by specifying 885 the `--security-opt` flag. For example, you can specify the MCS/MLS level, a 886 requirement for MLS systems. Specifying the level in the following command 887 allows you to share the same content between containers. 888 889 # docker run --security-opt label=level:s0:c100,c200 -i -t fedora bash 890 891 An MLS example might be: 892 893 # docker run --security-opt label=level:TopSecret -i -t rhel7 bash 894 895 To disable the security labeling for this container versus running with the 896 `--permissive` flag, use the following command: 897 898 # docker run --security-opt label=disable -i -t fedora bash 899 900 If you want a tighter security policy on the processes within a container, 901 you can specify an alternate type for the container. You could run a container 902 that is only allowed to listen on Apache ports by executing the following 903 command: 904 905 # docker run --security-opt label=type:svirt_apache_t -i -t centos bash 906 907 Note: 908 909 You would have to write policy defining a `svirt_apache_t` type. 910 911 ## Setting device weight 912 913 If you want to set `/dev/sda` device weight to `200`, you can specify the device 914 weight by `--blkio-weight-device` flag. Use the following command: 915 916 # docker run -it --blkio-weight-device "/dev/sda:200" ubuntu 917 918 ## Specify isolation technology for container (--isolation) 919 920 This option is useful in situations where you are running Docker containers on 921 Microsoft Windows. The `--isolation <value>` option sets a container's isolation 922 technology. On Linux, the only supported is the `default` option which uses 923 Linux namespaces. These two commands are equivalent on Linux: 924 925 ``` 926 $ docker run -d busybox top 927 $ docker run -d --isolation default busybox top 928 ``` 929 930 On Microsoft Windows, can take any of these values: 931 932 * `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 value. 933 * `process`: Namespace isolation only. 934 * `hyperv`: Hyper-V hypervisor partition-based isolation. 935 936 In practice, when running on Microsoft Windows without a `daemon` option set, these two commands are equivalent: 937 938 ``` 939 $ docker run -d --isolation default busybox top 940 $ docker run -d --isolation process busybox top 941 ``` 942 943 If you have set the `--exec-opt isolation=hyperv` option on the Docker `daemon`, any of these commands also result in `hyperv` isolation: 944 945 ``` 946 $ docker run -d --isolation default busybox top 947 $ docker run -d --isolation hyperv busybox top 948 ``` 949 950 # HISTORY 951 April 2014, Originally compiled by William Henry (whenry at redhat dot com) 952 based on docker.com source material and internal work. 953 June 2014, updated by Sven Dowideit <SvenDowideit@home.org.au> 954 July 2014, updated by Sven Dowideit <SvenDowideit@home.org.au> 955 November 2015, updated by Sally O'Malley <somalley@redhat.com>