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page_title: Command Line Interface page_description: Docker's CLI command description and usage page_keywords: Docker, Docker documentation, CLI, command line
Command Line
To list available commands, either run docker with no parameters
or execute docker help:
$ sudo docker
Usage: docker [OPTIONS] COMMAND [arg...]
-H, --host=[]: The socket(s) to bind to in daemon mode, specified using one or more tcp://host:port, unix:///path/to/socket, fd://* or fd://socketfd.
A self-sufficient runtime for linux containers.
...
Option types
Single character commandline options can be combined, so rather than
typing docker run -t -i --name test busybox sh,
you can write docker run -ti --name test busybox sh.
Boolean
Boolean options look like -d=false. The value you
see is the default value which gets set if you do not use the
boolean flag. If you do call run -d, that sets the
opposite boolean value, so in this case, true, and
so docker run -d will run in "detached" mode,
in the background. Other boolean options are similar – specifying them
will set the value to the opposite of the default value.
Multi
Options like -a=[] indicate they can be specified multiple times:
$ sudo docker run -a stdin -a stdout -a stderr -i -t ubuntu /bin/bash
Sometimes this can use a more complex value string, as for -v:
$ sudo docker run -v /host:/container example/mysql
Strings and Integers
Options like --name="" expect a string, and they
can only be specified once. Options like -c=0
expect an integer, and they can only be specified once.
daemon
Usage of docker:
--api-enable-cors=false Enable CORS headers in the remote API
-b, --bridge="" Attach containers to a pre-existing network bridge
use 'none' to disable container networking
--bip="" Use this CIDR notation address for the network bridge's IP, not compatible with -b
--fixed-cidr="" IPv4 subnet for fixed IPs (ex: 10.20.0.0/16)
this subnet must be nested in the bridge subnet (which is defined by -b or --bip)
-D, --debug=false Enable debug mode
-d, --daemon=false Enable daemon mode
--dns=[] Force Docker to use specific DNS servers
--dns-search=[] Force Docker to use specific DNS search domains
-e, --exec-driver="native" Force the Docker runtime to use a specific exec driver
-G, --group="docker" Group to assign the unix socket specified by -H when running in daemon mode
use '' (the empty string) to disable setting of a group
-g, --graph="/var/lib/docker" Path to use as the root of the Docker runtime
-H, --host=[] The socket(s) to bind to in daemon mode
specified using one or more tcp://host:port, unix:///path/to/socket, fd://* or fd://socketfd.
--icc=true Enable inter-container communication
--ip=0.0.0.0 Default IP address to use when binding container ports
--ip-forward=true Enable net.ipv4.ip_forward
--ip-masq=true Enable IP masquerading for bridge's IP range.
--iptables=true Enable Docker's addition of iptables rules
--mtu=0 Set the containers network MTU
if no value is provided: default to the default route MTU or 1500 if no default route is available
-p, --pidfile="/var/run/docker.pid" Path to use for daemon PID file
--registry-mirror=[] Specify a preferred Docker registry mirror
-s, --storage-driver="" Force the Docker runtime to use a specific storage driver
--selinux-enabled=false Enable selinux support. SELinux does not presently support the BTRFS storage driver
--storage-opt=[] Set storage driver options
--tls=false Use TLS; implied by tls-verify flags
--tlscacert="/home/sven/.docker/ca.pem" Trust only remotes providing a certificate signed by the CA given here
--tlscert="/home/sven/.docker/cert.pem" Path to TLS certificate file
--tlskey="/home/sven/.docker/key.pem" Path to TLS key file
--tlsverify=false Use TLS and verify the remote (daemon: verify client, client: verify daemon)
-v, --version=false Print version information and quit
Options with [] may be specified multiple times.
The Docker daemon is the persistent process that manages containers.
Docker uses the same binary for both the daemon and client. To run the
daemon you provide the -d flag.
To force Docker to use devicemapper as the storage driver, use
docker -d -s devicemapper.
To set the DNS server for all Docker containers, use
docker -d --dns 8.8.8.8.
To set the DNS search domain for all Docker containers, use
docker -d --dns-search example.com.
To run the daemon with debug output, use docker -d -D.
To use lxc as the execution driver, use docker -d -e lxc.
The docker client will also honor the DOCKER_HOST environment variable to set
the -H flag for the client.
$ sudo docker -H tcp://0.0.0.0:2375 ps
# or
$ export DOCKER_HOST="tcp://0.0.0.0:2375"
$ sudo docker ps
# both are equal
IP masquerading uses address translation to allow containers without a public IP to talk to other machines on the Internet. This may interfere with some network topologies and can be disabled with --ip-masq=false.
To run the daemon with systemd socket activation, use
docker -d -H fd://. Using fd:// will work perfectly for most setups but
you can also specify individual sockets too docker -d -H fd://3. If the
specified socket activated files aren't found then docker will exit. You
can find examples of using systemd socket activation with docker and
systemd in the docker source tree.
Docker supports softlinks for the Docker data directory
(/var/lib/docker) and for /var/lib/docker/tmp. The DOCKER_TMPDIR and the data directory can be set like this:
DOCKER_TMPDIR=/mnt/disk2/tmp /usr/local/bin/docker -d -D -g /var/lib/docker -H unix:// > /var/lib/boot2docker/docker.log 2>&1
# or
export DOCKER_TMPDIR=/mnt/disk2/tmp
/usr/local/bin/docker -d -D -g /var/lib/docker -H unix:// > /var/lib/boot2docker/docker.log 2>&1
attach
Usage: docker attach [OPTIONS] CONTAINER
Attach to a running container
--no-stdin=false Do not attach STDIN
--sig-proxy=true Proxy all received signals to the process (even in non-TTY mode). SIGCHLD, SIGKILL, and SIGSTOP are not proxied.
The attach command will allow you to view or
interact with any running container, detached (-d)
or interactive (-i). You can attach to the same
container at the same time - screen sharing style, or quickly view the
progress of your daemonized process.
You can detach from the container again (and leave it running) with
CTRL-p CTRL-q (for a quiet exit), or CTRL-c which will send a
SIGKILL to the container, or CTRL-\ to get a stacktrace of the
Docker client when it quits. When you detach from the container's
process the exit code will be returned to the client.
To stop a container, use docker stop.
To kill the container, use docker kill.
Examples:
$ ID=$(sudo docker run -d ubuntu /usr/bin/top -b)
$ sudo docker attach $ID
top - 02:05:52 up 3:05, 0 users, load average: 0.01, 0.02, 0.05
Tasks: 1 total, 1 running, 0 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.1%us, 0.2%sy, 0.0%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 373572k total, 355560k used, 18012k free, 27872k buffers
Swap: 786428k total, 0k used, 786428k free, 221740k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1 root 20 0 17200 1116 912 R 0 0.3 0:00.03 top
top - 02:05:55 up 3:05, 0 users, load average: 0.01, 0.02, 0.05
Tasks: 1 total, 1 running, 0 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, 0.2%sy, 0.0%ni, 99.8%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 373572k total, 355244k used, 18328k free, 27872k buffers
Swap: 786428k total, 0k used, 786428k free, 221776k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1 root 20 0 17208 1144 932 R 0 0.3 0:00.03 top
top - 02:05:58 up 3:06, 0 users, load average: 0.01, 0.02, 0.05
Tasks: 1 total, 1 running, 0 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.2%us, 0.3%sy, 0.0%ni, 99.5%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 373572k total, 355780k used, 17792k free, 27880k buffers
Swap: 786428k total, 0k used, 786428k free, 221776k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1 root 20 0 17208 1144 932 R 0 0.3 0:00.03 top
^C$
$ sudo docker stop $ID
build
Usage: docker build [OPTIONS] PATH | URL | -
Build a new image from the source code at PATH
--force-rm=false Always remove intermediate containers, even after unsuccessful builds
--no-cache=false Do not use cache when building the image
-q, --quiet=false Suppress the verbose output generated by the containers
--rm=true Remove intermediate containers after a successful build
-t, --tag="" Repository name (and optionally a tag) to be applied to the resulting image in case of success
Use this command to build Docker images from a Dockerfile and a "context".
The files at PATH or URL are called the "context" of the build. The
build process may refer to any of the files in the context, for example
when using an ADD instruction.
When a single Dockerfile is given as URL or is piped through STDIN
(docker build - < Dockerfile), then no context is set.
When a Git repository is set as URL, then the repository is used as
the context. The Git repository is cloned with its submodules
(git clone -recursive). A fresh git clone occurs in a temporary directory
on your local host, and then this is sent to the Docker daemon as the
context. This way, your local user credentials and VPN's etc can be
used to access private repositories.
If a file named .dockerignore exists in the root of PATH then it
is interpreted as a newline-separated list of exclusion patterns.
Exclusion patterns match files or directories relative to PATH that
will be excluded from the context. Globbing is done using Go's
filepath.Match rules.
See also:
Examples:
$ sudo docker build .
Uploading context 10240 bytes
Step 1 : FROM busybox
Pulling repository busybox
---> e9aa60c60128MB/2.284 MB (100%) endpoint: https://cdn-registry-1.docker.io/v1/
Step 2 : RUN ls -lh /
---> Running in 9c9e81692ae9
total 24
drwxr-xr-x 2 root root 4.0K Mar 12 2013 bin
drwxr-xr-x 5 root root 4.0K Oct 19 00:19 dev
drwxr-xr-x 2 root root 4.0K Oct 19 00:19 etc
drwxr-xr-x 2 root root 4.0K Nov 15 23:34 lib
lrwxrwxrwx 1 root root 3 Mar 12 2013 lib64 -> lib
dr-xr-xr-x 116 root root 0 Nov 15 23:34 proc
lrwxrwxrwx 1 root root 3 Mar 12 2013 sbin -> bin
dr-xr-xr-x 13 root root 0 Nov 15 23:34 sys
drwxr-xr-x 2 root root 4.0K Mar 12 2013 tmp
drwxr-xr-x 2 root root 4.0K Nov 15 23:34 usr
---> b35f4035db3f
Step 3 : CMD echo Hello world
---> Running in 02071fceb21b
---> f52f38b7823e
Successfully built f52f38b7823e
Removing intermediate container 9c9e81692ae9
Removing intermediate container 02071fceb21b
This example specifies that the PATH is
., and so all the files in the local directory get
tard and sent to the Docker daemon. The PATH
specifies where to find the files for the "context" of the build on the
Docker daemon. Remember that the daemon could be running on a remote
machine and that no parsing of the Dockerfile
happens at the client side (where you're running
docker build). That means that all the files at
PATH get sent, not just the ones listed to
ADD in the Dockerfile.
The transfer of context from the local machine to the Docker daemon is
what the docker client means when you see the
"Sending build context" message.
If you wish to keep the intermediate containers after the build is
complete, you must use --rm=false. This does not
affect the build cache.
$ sudo docker build .
Uploading context 18.829 MB
Uploading context
Step 0 : FROM busybox
---> 769b9341d937
Step 1 : CMD echo Hello world
---> Using cache
---> 99cc1ad10469
Successfully built 99cc1ad10469
$ echo ".git" > .dockerignore
$ sudo docker build .
Uploading context 6.76 MB
Uploading context
Step 0 : FROM busybox
---> 769b9341d937
Step 1 : CMD echo Hello world
---> Using cache
---> 99cc1ad10469
Successfully built 99cc1ad10469
This example shows the use of the .dockerignore file to exclude the .git
directory from the context. Its effect can be seen in the changed size of the
uploaded context.
$ sudo docker build -t vieux/apache:2.0 .
This will build like the previous example, but it will then tag the
resulting image. The repository name will be vieux/apache
and the tag will be 2.0
$ sudo docker build - < Dockerfile
This will read a Dockerfile from STDIN without context. Due to the
lack of a context, no contents of any local directory will be sent to
the Docker daemon. Since there is no context, a Dockerfile ADD only
works if it refers to a remote URL.
$ sudo docker build - < context.tar.gz
This will build an image for a compressed context read from STDIN.
Supported formats are: bzip2, gzip and xz.
$ sudo docker build github.com/creack/docker-firefox
This will clone the GitHub repository and use the cloned repository as
context. The Dockerfile at the root of the
repository is used as Dockerfile. Note that you
can specify an arbitrary Git repository by using the git://
schema.
Note:
docker buildwill return ano such file or directoryerror if the file or directory does not exist in the uploaded context. This may happen if there is no context, or if you specify a file that is elsewhere on the Host system. The context is limited to the current directory (and its children) for security reasons, and to ensure repeatable builds on remote Docker hosts. This is also the reason whyADD ../filewill not work.
commit
Usage: docker commit [OPTIONS] CONTAINER [REPOSITORY[:TAG]]
Create a new image from a container's changes
-a, --author="" Author (e.g., "John Hannibal Smith <hannibal@a-team.com>")
-m, --message="" Commit message
-p, --pause=true Pause container during commit
It can be useful to commit a container's file changes or settings into a new image. This allows you debug a container by running an interactive shell, or to export a working dataset to another server. Generally, it is better to use Dockerfiles to manage your images in a documented and maintainable way.
By default, the container being committed and its processes will be paused while the image is committed. This reduces the likelihood of encountering data corruption during the process of creating the commit. If this behavior is undesired, set the 'p' option to false.
Commit an existing container
$ sudo docker ps
ID IMAGE COMMAND CREATED STATUS PORTS
c3f279d17e0a ubuntu:12.04 /bin/bash 7 days ago Up 25 hours
197387f1b436 ubuntu:12.04 /bin/bash 7 days ago Up 25 hours
$ sudo docker commit c3f279d17e0a SvenDowideit/testimage:version3
f5283438590d
$ sudo docker images | head
REPOSITORY TAG ID CREATED VIRTUAL SIZE
SvenDowideit/testimage version3 f5283438590d 16 seconds ago 335.7 MB
cp
Copy files/folders from a container's filesystem to the host path. Paths are relative to the root of the filesystem.
Usage: docker cp CONTAINER:PATH HOSTPATH
Copy files/folders from the PATH to the HOSTPATH
create
Creates a new container.
Usage: docker create [OPTIONS] IMAGE[:TAG] [COMMAND] [ARG...]
-a, --attach=[] Attach to STDIN, STDOUT, STDERR.
-c, --cpu-shares=0 CPU shares (relative weight)
--cidfile="" Write the container ID to the file
--dns=[] Set custom DNS servers
--dns-search=[] Set custom DNS search domains
-e, --env=[] Set environment variables
--entrypoint="" Overwrite the default entrypoint of the image
--env-file=[] Read in a line delimited file of environment variables
--expose=[] Expose a port from the container without publishing it to your host
-h, --hostname="" Container host name
-i, --interactive=false Keep `STDIN` open even if not attached
--link=[] Add link to another container (name:alias)
--lxc-conf=[] (lxc exec-driver only) Add custom lxc options --lxc-conf="lxc.cgroup.cpuset.cpus = 0,1"
-m, --memory="" Memory limit (format: <number><optional unit>, where unit = b, k, m or g)
--name="" Assign a name to the container
--net="bridge" Set the Network mode for the container
'bridge': creates a new network stack for the container on the docker bridge
'none': no networking for this container
'container:<name|id>': reuses another container network stack
'host': use the host network stack inside the container
-p, --publish=[] Publish a container's port to the host
format: ip:hostPort:containerPort | ip::containerPort | hostPort:containerPort
(use 'docker port' to see the actual mapping)
-P, --publish-all=false Publish all exposed ports to the host interfaces
--privileged=false Give extended privileges to this container
-t, --tty=false Allocate a pseudo-TTY
-u, --user="" Username or UID
-v, --volume=[] Bind mount a volume (e.g. from the host: -v /host:/container, from docker: -v /container)
--volumes-from=[] Mount volumes from the specified container(s)
-w, --workdir="" Working directory inside the container
The docker create command creates a writeable container layer over
the specified image and prepares it for running the specified command.
The container ID is then printed to STDOUT.
This is similar to docker run -d except the container is never started.
You can then use the docker start <container_id> command to start the
container at any point.
This is useful when you want to set up a container configuration ahead of time so that it is ready to start when you need it.
Example:
$ sudo docker create -t -i fedora bash
6d8af538ec541dd581ebc2a24153a28329acb5268abe5ef868c1f1a261221752
$ sudo docker start -a -i 6d8af538ec5
bash-4.2#
diff
List the changed files and directories in a container᾿s filesystem
Usage: docker diff CONTAINER
Inspect changes on a container's filesystem
There are 3 events that are listed in the diff:
A- AddD- DeleteC- Change
For example:
$ sudo docker diff 7bb0e258aefe
C /dev
A /dev/kmsg
C /etc
A /etc/mtab
A /go
A /go/src
A /go/src/github.com
A /go/src/github.com/docker
A /go/src/github.com/docker/docker
A /go/src/github.com/docker/docker/.git
....
events
Usage: docker events [OPTIONS]
Get real time events from the server
--since="" Show all events created since timestamp
--until="" Stream events until this timestamp
Examples
You'll need two shells for this example.
Shell 1: Listening for events:
$ sudo docker events
Shell 2: Start and Stop a Container:
$ sudo docker start 4386fb97867d
$ sudo docker stop 4386fb97867d
Shell 1: (Again .. now showing events):
2014-05-10T17:42:14.999999999Z07:00 4386fb97867d: (from 12de384bfb10) start
2014-05-10T17:42:14.999999999Z07:00 4386fb97867d: (from 12de384bfb10) die
2014-05-10T17:42:14.999999999Z07:00 4386fb97867d: (from 12de384bfb10) stop
Show events in the past from a specified time:
$ sudo docker events --since 1378216169
2014-03-10T17:42:14.999999999Z07:00 4386fb97867d: (from 12de384bfb10) die
2014-03-10T17:42:14.999999999Z07:00 4386fb97867d: (from 12de384bfb10) stop
$ sudo docker events --since '2013-09-03'
2014-09-03T17:42:14.999999999Z07:00 4386fb97867d: (from 12de384bfb10) start
2014-09-03T17:42:14.999999999Z07:00 4386fb97867d: (from 12de384bfb10) die
2014-09-03T17:42:14.999999999Z07:00 4386fb97867d: (from 12de384bfb10) stop
$ sudo docker events --since '2013-09-03 15:49:29 +0200 CEST'
2014-09-03T15:49:29.999999999Z07:00 4386fb97867d: (from 12de384bfb10) die
2014-09-03T15:49:29.999999999Z07:00 4386fb97867d: (from 12de384bfb10) stop
exec
Usage: docker exec CONTAINER COMMAND [ARG...]
Run a command in an existing container
-d, --detach=false Detached mode: run the process in the background and exit
-i, --interactive=false Keep STDIN open even if not attached
-t, --tty=false Allocate a pseudo-TTY
The docker exec command runs a user specified command as a new process in an existing
user specified container. The container needs to be active.
The docker exec command will typically be used after docker run.
Examples:
$ sudo docker run --name ubuntu_bash --rm -i -t ubuntu bash
This will create a container named 'ubuntu_bash' and start a bash session.
$ sudo docker exec -d ubuntu_bash touch /tmp/execWorks
This will create a new file '/tmp/execWorks' inside the existing and active container 'ubuntu_bash', in the background.
$ sudo docker exec ubuntu_bash -it bash
This will create a new bash session in the container 'ubuntu_bash'.
export
Usage: docker export CONTAINER
Export the contents of a filesystem as a tar archive to STDOUT
For example:
$ sudo docker export red_panda > latest.tar
history
Usage: docker history [OPTIONS] IMAGE
Show the history of an image
--no-trunc=false Don't truncate output
-q, --quiet=false Only show numeric IDs
To see how the docker:latest image was built:
$ sudo docker history docker
IMAGE CREATED CREATED BY SIZE
3e23a5875458790b7a806f95f7ec0d0b2a5c1659bfc899c89f939f6d5b8f7094 8 days ago /bin/sh -c #(nop) ENV LC_ALL=C.UTF-8 0 B
8578938dd17054dce7993d21de79e96a037400e8d28e15e7290fea4f65128a36 8 days ago /bin/sh -c dpkg-reconfigure locales && locale-gen C.UTF-8 && /usr/sbin/update-locale LANG=C.UTF-8 1.245 MB
be51b77efb42f67a5e96437b3e102f81e0a1399038f77bf28cea0ed23a65cf60 8 days ago /bin/sh -c apt-get update && apt-get install -y git libxml2-dev python build-essential make gcc python-dev locales python-pip 338.3 MB
4b137612be55ca69776c7f30c2d2dd0aa2e7d72059820abf3e25b629f887a084 6 weeks ago /bin/sh -c #(nop) ADD jessie.tar.xz in / 121 MB
750d58736b4b6cc0f9a9abe8f258cef269e3e9dceced1146503522be9f985ada 6 weeks ago /bin/sh -c #(nop) MAINTAINER Tianon Gravi <admwiggin@gmail.com> - mkimage-debootstrap.sh -t jessie.tar.xz jessie http://http.debian.net/debian 0 B
511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158 9 months ago 0 B
images
Usage: docker images [OPTIONS] [NAME]
List images
-a, --all=false Show all images (by default filter out the intermediate image layers)
-f, --filter=[] Provide filter values (i.e. 'dangling=true')
--no-trunc=false Don't truncate output
-q, --quiet=false Only show numeric IDs
The default docker images will show all top level
images, their repository and tags, and their virtual size.
Docker images have intermediate layers that increase reusability,
decrease disk usage, and speed up docker build by
allowing each step to be cached. These intermediate layers are not shown
by default.
Listing the most recently created images
$ sudo docker images | head
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
<none> <none> 77af4d6b9913 19 hours ago 1.089 GB
committest latest b6fa739cedf5 19 hours ago 1.089 GB
<none> <none> 78a85c484f71 19 hours ago 1.089 GB
docker latest 30557a29d5ab 20 hours ago 1.089 GB
<none> <none> 0124422dd9f9 20 hours ago 1.089 GB
<none> <none> 18ad6fad3402 22 hours ago 1.082 GB
<none> <none> f9f1e26352f0 23 hours ago 1.089 GB
tryout latest 2629d1fa0b81 23 hours ago 131.5 MB
<none> <none> 5ed6274db6ce 24 hours ago 1.089 GB
Listing the full length image IDs
$ sudo docker images --no-trunc | head
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
<none> <none> 77af4d6b9913e693e8d0b4b294fa62ade6054e6b2f1ffb617ac955dd63fb0182 19 hours ago 1.089 GB
committest latest b6fa739cedf5ea12a620a439402b6004d057da800f91c7524b5086a5e4749c9f 19 hours ago 1.089 GB
<none> <none> 78a85c484f71509adeaace20e72e941f6bdd2b25b4c75da8693efd9f61a37921 19 hours ago 1.089 GB
docker latest 30557a29d5abc51e5f1d5b472e79b7e296f595abcf19fe6b9199dbbc809c6ff4 20 hours ago 1.089 GB
<none> <none> 0124422dd9f9cf7ef15c0617cda3931ee68346455441d66ab8bdc5b05e9fdce5 20 hours ago 1.089 GB
<none> <none> 18ad6fad340262ac2a636efd98a6d1f0ea775ae3d45240d3418466495a19a81b 22 hours ago 1.082 GB
<none> <none> f9f1e26352f0a3ba6a0ff68167559f64f3e21ff7ada60366e2d44a04befd1d3a 23 hours ago 1.089 GB
tryout latest 2629d1fa0b81b222fca63371ca16cbf6a0772d07759ff80e8d1369b926940074 23 hours ago 131.5 MB
<none> <none> 5ed6274db6ceb2397844896966ea239290555e74ef307030ebb01ff91b1914df 24 hours ago 1.089 GB
Filtering
The filtering flag (-f or --filter) format is of "key=value". If there are more
than one filter, then pass multiple flags (e.g., --filter "foo=bar" --filter "bif=baz")
Current filters:
- dangling (boolean - true or false)
untagged images
$ sudo docker images --filter "dangling=true"
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
<none> <none> 8abc22fbb042 4 weeks ago 0 B
<none> <none> 48e5f45168b9 4 weeks ago 2.489 MB
<none> <none> bf747efa0e2f 4 weeks ago 0 B
<none> <none> 980fe10e5736 12 weeks ago 101.4 MB
<none> <none> dea752e4e117 12 weeks ago 101.4 MB
<none> <none> 511136ea3c5a 8 months ago 0 B
This will display untagged images, that are the leaves of the images tree (not intermediary layers). These images occur when a new build of an image takes the repo:tag away from the IMAGE ID, leaving it untagged. A warning will be issued if trying to remove an image when a container is presently using it. By having this flag it allows for batch cleanup.
Ready for use by docker rmi ..., like:
$ sudo docker rmi $(sudo docker images -f "dangling=true" -q)
8abc22fbb042
48e5f45168b9
bf747efa0e2f
980fe10e5736
dea752e4e117
511136ea3c5a
NOTE: Docker will warn you if any containers exist that are using these untagged images.
import
Usage: docker import URL|- [REPOSITORY[:TAG]]
Create an empty filesystem image and import the contents of the tarball (.tar, .tar.gz, .tgz, .bzip, .tar.xz, .txz) into it, then optionally tag it.
URLs must start with http and point to a single file archive (.tar,
.tar.gz, .tgz, .bzip, .tar.xz, or .txz) containing a root filesystem. If
you would like to import from a local directory or archive, you can use
the - parameter to take the data from STDIN.
Examples
Import from a remote location:
This will create a new untagged image.
$ sudo docker import http://example.com/exampleimage.tgz
Import from a local file:
Import to docker via pipe and STDIN.
$ cat exampleimage.tgz | sudo docker import - exampleimagelocal:new
Import from a local directory:
$ sudo tar -c . | sudo docker import - exampleimagedir
Note the sudo in this example – you must preserve
the ownership of the files (especially root ownership) during the
archiving with tar. If you are not root (or the sudo command) when you
tar, then the ownerships might not get preserved.
info
Usage: docker info
Display system-wide information
For example:
$ sudo docker -D info
Containers: 14
Images: 52
Storage Driver: btrfs
Execution Driver: native-0.2
Kernel Version: 3.13.0-24-generic
Operating System: Ubuntu 14.04 LTS
Debug mode (server): false
Debug mode (client): true
Fds: 10
Goroutines: 9
EventsListeners: 0
Init Path: /usr/bin/docker
Username: svendowideit
Registry: [https://index.docker.io/v1/]
The global -D option tells all docker comands to output debug information.
When sending issue reports, please use docker version and docker -D info to
ensure we know how your setup is configured.
inspect
Usage: docker inspect [OPTIONS] CONTAINER|IMAGE [CONTAINER|IMAGE...]
Return low-level information on a container or image
-f, --format="" Format the output using the given go template.
By default, this will render all results in a JSON array. If a format is specified, the given template will be executed for each result.
Go's text/template package describes all the details of the format.
Examples
Get an instance'sIP Address:
For the most part, you can pick out any field from the JSON in a fairly straightforward manner.
$ sudo docker inspect --format='{{.NetworkSettings.IPAddress}}' $INSTANCE_ID
List All Port Bindings:
One can loop over arrays and maps in the results to produce simple text output:
$ sudo docker inspect --format='{{range $p, $conf := .NetworkSettings.Ports}} {{$p}} -> {{(index $conf 0).HostPort}} {{end}}' $INSTANCE_ID
Find a Specific Port Mapping:
The .Field syntax doesn't work when the field name
begins with a number, but the template language's index
function does. The .NetworkSettings.Ports
section contains a map of the internal port mappings to a list
of external address/port objects, so to grab just the numeric public
port, you use index to find the specific port map,
and then index 0 contains first object inside of
that. Then we ask for the HostPort field to get
the public address.
$ sudo docker inspect --format='{{(index (index .NetworkSettings.Ports "8787/tcp") 0).HostPort}}' $INSTANCE_ID
Get config:
The .Field syntax doesn't work when the field
contains JSON data, but the template language's custom json
function does. The .config section
contains complex json object, so to grab it as JSON, you use
json to convert config object into JSON
$ sudo docker inspect --format='{{json .config}}' $INSTANCE_ID
kill
Usage: docker kill [OPTIONS] CONTAINER [CONTAINER...]
Kill a running container using SIGKILL or a specified signal
-s, --signal="KILL" Signal to send to the container
The main process inside the container will be sent SIGKILL, or any
signal specified with option --signal.
load
Usage: docker load [OPTIONS]
Load an image from a tar archive on STDIN
-i, --input="" Read from a tar archive file, instead of STDIN
Loads a tarred repository from a file or the standard input stream. Restores both images and tags.
$ sudo docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
$ sudo docker load < busybox.tar
$ sudo docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
busybox latest 769b9341d937 7 weeks ago 2.489 MB
$ sudo docker load --input fedora.tar
$ sudo docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
busybox latest 769b9341d937 7 weeks ago 2.489 MB
fedora rawhide 0d20aec6529d 7 weeks ago 387 MB
fedora 20 58394af37342 7 weeks ago 385.5 MB
fedora heisenbug 58394af37342 7 weeks ago 385.5 MB
fedora latest 58394af37342 7 weeks ago 385.5 MB
login
Usage: docker login [OPTIONS] [SERVER]
Register or log in to a Docker registry server, if no server is specified "https://index.docker.io/v1/" is the default.
-e, --email="" Email
-p, --password="" Password
-u, --username="" Username
If you want to login to a self-hosted registry you can specify this by adding the server name.
example:
$ sudo docker login localhost:8080
logout
Usage: docker logout [SERVER]
Log out from a Docker registry, if no server is specified "https://index.docker.io/v1/" is the default.
For example:
$ sudo docker logout localhost:8080
logs
Usage: docker logs [OPTIONS] CONTAINER
Fetch the logs of a container
-f, --follow=false Follow log output
-t, --timestamps=false Show timestamps
--tail="all" Output the specified number of lines at the end of logs (defaults to all logs)
The docker logs command batch-retrieves logs present at the time of execution.
The docker logs --follow command will continue streaming the new output from
the container's STDOUT and STDERR.
Passing a negative number or a non-integer to --tail is invalid and the
value is set to all in that case. This behavior may change in the future.
The docker logs --timestamp commands will add an RFC3339Nano
timestamp, for example 2014-09-16T06:17:46.000000000Z, to each
log entry. To ensure that the timestamps for are aligned the
nano-second part of the timestamp will be padded with zero when necessary.
port
Usage: docker port CONTAINER [PRIVATE_PORT[/PROTO]]
List port mappings for the CONTAINER, or lookup the public-facing port that is NAT-ed to the PRIVATE_PORT
You can find out all the ports mapped by not specifying a PRIVATE_PORT, or
just a specific mapping:
$ sudo docker ps test
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
b650456536c7 busybox:latest top 54 minutes ago Up 54 minutes 0.0.0.0:1234->9876/tcp, 0.0.0.0:4321->7890/tcp test
$ sudo docker port test
7890/tcp -> 0.0.0.0:4321
9876/tcp -> 0.0.0.0:1234
$ sudo docker port test 7890/tcp
0.0.0.0:4321
$ sudo docker port test 7890/udp
2014/06/24 11:53:36 Error: No public port '7890/udp' published for test
$ sudo docker port test 7890
0.0.0.0:4321
pause
Usage: docker pause CONTAINER
Pause all processes within a container
The docker pause command uses the cgroups freezer to suspend all processes in
a container. Traditionally when suspending a process the SIGSTOP signal is
used, which is observable by the process being suspended. With the cgroups freezer
the process is unaware, and unable to capture, that it is being suspended,
and subsequently resumed.
See the [cgroups freezer documentation] (https://www.kernel.org/doc/Documentation/cgroups/freezer-subsystem.txt) for further details.
ps
Usage: docker ps [OPTIONS]
List containers
-a, --all=false Show all containers. Only running containers are shown by default.
--before="" Show only container created before Id or Name, include non-running ones.
-f, --filter=[] Provide filter values. Valid filters:
exited=<int> - containers with exit code of <int>
-l, --latest=false Show only the latest created container, include non-running ones.
-n=-1 Show n last created containers, include non-running ones.
--no-trunc=false Don't truncate output
-q, --quiet=false Only display numeric IDs
-s, --size=false Display sizes
--since="" Show only containers created since Id or Name, include non-running ones.
Running docker ps showing 2 linked containers.
$ sudo docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
4c01db0b339c ubuntu:12.04 bash 17 seconds ago Up 16 seconds webapp
d7886598dbe2 crosbymichael/redis:latest /redis-server --dir 33 minutes ago Up 33 minutes 6379/tcp redis,webapp/db
docker ps will show only running containers by default. To see all containers:
docker ps -a
Filtering
The filtering flag (-f or --filter) format is a "key=value" pair. If there is more
than one filter, then pass multiple flags (e.g. --filter "foo=bar" --filter "bif=baz")
Current filters:
- exited (int - the code of exited containers. Only useful with '--all')
Successfully exited containers
$ sudo docker ps -a --filter 'exited=0'
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
ea09c3c82f6e registry:latest /srv/run.sh 2 weeks ago Exited (0) 2 weeks ago 127.0.0.1:5000->5000/tcp desperate_leakey
106ea823fe4e fedora:latest /bin/sh -c 'bash -l' 2 weeks ago Exited (0) 2 weeks ago determined_albattani
48ee228c9464 fedora:20 bash 2 weeks ago Exited (0) 2 weeks ago tender_torvalds
This shows all the containers that have exited with status of '0'
pull
Usage: docker pull [OPTIONS] NAME[:TAG]
Pull an image or a repository from the registry
-a, --all-tags=false Download all tagged images in the repository
Most of your images will be created on top of a base image from the Docker Hub registry.
Docker Hub contains many pre-built images that you
can pull and try without needing to define and configure your own.
It is also possible to manually specify the path of a registry to pull from. For example, if you have set up a local registry, you can specify its path to pull from it. A repository path is similar to a URL, but does not contain a protocol specifier (https://, for example).
To download a particular image, or set of images (i.e., a repository),
use docker pull:
$ sudo docker pull debian
# will pull only the debian:latest image and its intermediate layers
$ sudo docker pull debian:testing
# will pull only the image named debian:testing and any intermediate layers
# it is based on. (Typically the empty `scratch` image, a MAINTAINER layer,
# and the un-tarred base).
$ sudo docker pull --all-tags centos
# will pull all the images from the centos repository
$ sudo docker pull registry.hub.docker.com/debian
# manually specifies the path to the default Docker registry. This could
# be replaced with the path to a local registry to pull from another source.
push
Usage: docker push NAME[:TAG]
Push an image or a repository to the registry
Use docker push to share your images to the Docker Hub
registry or to a self-hosted one.
restart
Usage: docker restart [OPTIONS] CONTAINER [CONTAINER...]
Restart a running container
-t, --time=10 Number of seconds to try to stop for before killing the container. Once killed it will then be restarted. Default is 10 seconds.
rm
Usage: docker rm [OPTIONS] CONTAINER [CONTAINER...]
Remove one or more containers
-f, --force=false Force the removal of a running container (uses SIGKILL)
-l, --link=false Remove the specified link and not the underlying container
-v, --volumes=false Remove the volumes associated with the container
Known Issues (rm)
- Issue 197 indicates
that
docker killmay leave directories behind and make it difficult to remove the container.
Examples:
$ sudo docker rm /redis
/redis
This will remove the container referenced under the link
/redis.
$ sudo docker rm --link /webapp/redis
/webapp/redis
This will remove the underlying link between /webapp
and the /redis containers removing all
network communication.
$ sudo docker rm --force redis
redis
The main process inside the container referenced under the link /redis will receive
SIGKILL, then the container will be removed.
This command will delete all stopped containers. The command
docker ps -a -q will return all existing container
IDs and pass them to the rm command which will
delete them. Any running containers will not be deleted.
rmi
Usage: docker rmi [OPTIONS] IMAGE [IMAGE...]
Remove one or more images
-f, --force=false Force removal of the image
--no-prune=false Do not delete untagged parents
Removing tagged images
Images can be removed either by their short or long ID`s, or their image names. If an image has more than one name, each of them needs to be removed before the image is removed.
$ sudo docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
test1 latest fd484f19954f 23 seconds ago 7 B (virtual 4.964 MB)
test latest fd484f19954f 23 seconds ago 7 B (virtual 4.964 MB)
test2 latest fd484f19954f 23 seconds ago 7 B (virtual 4.964 MB)
$ sudo docker rmi fd484f19954f
Error: Conflict, cannot delete image fd484f19954f because it is tagged in multiple repositories
2013/12/11 05:47:16 Error: failed to remove one or more images
$ sudo docker rmi test1
Untagged: fd484f19954f4920da7ff372b5067f5b7ddb2fd3830cecd17b96ea9e286ba5b8
$ sudo docker rmi test2
Untagged: fd484f19954f4920da7ff372b5067f5b7ddb2fd3830cecd17b96ea9e286ba5b8
$ sudo docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
test latest fd484f19954f 23 seconds ago 7 B (virtual 4.964 MB)
$ sudo docker rmi test
Untagged: fd484f19954f4920da7ff372b5067f5b7ddb2fd3830cecd17b96ea9e286ba5b8
Deleted: fd484f19954f4920da7ff372b5067f5b7ddb2fd3830cecd17b96ea9e286ba5b8
run
Usage: docker run [OPTIONS] IMAGE [COMMAND] [ARG...]
Run a command in a new container
-a, --attach=[] Attach to STDIN, STDOUT or STDERR.
--add-host=[] Add a custom host-to-IP mapping (host:ip)
-c, --cpu-shares=0 CPU shares (relative weight)
--cap-add=[] Add Linux capabilities
--cap-drop=[] Drop Linux capabilities
--cidfile="" Write the container ID to the file
--cpuset="" CPUs in which to allow execution (0-3, 0,1)
-d, --detach=false Detached mode: run container in the background and print new container ID
--device=[] Add a host device to the container (e.g. --device=/dev/sdc:/dev/xvdc)
--dns=[] Set custom DNS servers
--dns-search=[] Set custom DNS search domains
-e, --env=[] Set environment variables
--entrypoint="" Overwrite the default ENTRYPOINT of the image
--env-file=[] Read in a line delimited file of environment variables
--expose=[] Expose a port from the container without publishing it to your host
-h, --hostname="" Container host name
-i, --interactive=false Keep STDIN open even if not attached
--link=[] Add link to another container in the form of name:alias
--lxc-conf=[] (lxc exec-driver only) Add custom lxc options --lxc-conf="lxc.cgroup.cpuset.cpus = 0,1"
-m, --memory="" Memory limit (format: <number><optional unit>, where unit = b, k, m or g)
--name="" Assign a name to the container
--net="bridge" Set the Network mode for the container
'bridge': creates a new network stack for the container on the docker bridge
'none': no networking for this container
'container:<name|id>': reuses another container network stack
'host': use the host network stack inside the container. Note: the host mode gives the container full access to local system services such as D-bus and is therefore considered insecure.
-P, --publish-all=false Publish all exposed ports to the host interfaces
-p, --publish=[] Publish a container's port to the host
format: ip:hostPort:containerPort | ip::containerPort | hostPort:containerPort | containerPort
(use 'docker port' to see the actual mapping)
--privileged=false Give extended privileges to this container
--restart="" Restart policy to apply when a container exits (no, on-failure[:max-retry], always)
--rm=false Automatically remove the container when it exits (incompatible with -d)
--sig-proxy=true Proxy received signals to the process (even in non-TTY mode). SIGCHLD, SIGSTOP, and SIGKILL are not proxied.
-t, --tty=false Allocate a pseudo-TTY
-u, --user="" Username or UID
-v, --volume=[] Bind mount a volume (e.g., from the host: -v /host:/container, from Docker: -v /container)
--volumes-from=[] Mount volumes from the specified container(s)
-w, --workdir="" Working directory inside the container
The docker run command first creates a writeable container layer over the
specified image, and then starts it using the specified command. That is,
docker run is equivalent to the API /containers/create then
/containers/(id)/start. A stopped container can be restarted with all its
previous changes intact using docker start. See docker ps -a to view a list
of all containers.
The docker run command can be used in combination with docker commit to
change the command that a container runs.
See the Docker User Guide for more detailed
information about the --expose, -p, -P and --link parameters,
and linking containers.
Known Issues (run –volumes-from)
- Issue 2702: "lxc-start: Permission denied - failed to mount" could indicate a permissions problem with AppArmor. Please see the issue for a workaround.
Examples:
$ sudo docker run --cidfile /tmp/docker_test.cid ubuntu echo "test"
This will create a container and print test to the console. The cidfile
flag makes Docker attempt to create a new file and write the container ID to it.
If the file exists already, Docker will return an error. Docker will close this
file when docker run exits.
$ sudo docker run -t -i --rm ubuntu bash
root@bc338942ef20:/# mount -t tmpfs none /mnt
mount: permission denied
This will not work, because by default, most potentially dangerous kernel
capabilities are dropped; including cap_sys_admin (which is required to mount
filesystems). However, the --privileged flag will allow it to run:
$ sudo docker run --privileged ubuntu bash
root@50e3f57e16e6:/# mount -t tmpfs none /mnt
root@50e3f57e16e6:/# df -h
Filesystem Size Used Avail Use% Mounted on
none 1.9G 0 1.9G 0% /mnt
The --privileged flag gives all capabilities to the container, and it also
lifts all the limitations enforced by the device cgroup controller. In other
words, the container can then do almost everything that the host can do. This
flag exists to allow special use-cases, like running Docker within Docker.
$ sudo docker run -w /path/to/dir/ -i -t ubuntu pwd
The -w lets the command being executed inside directory given, here
/path/to/dir/. If the path does not exists it is created inside the container.
$ sudo docker run -v `pwd`:`pwd` -w `pwd` -i -t ubuntu pwd
The -v flag mounts the current working directory into the container. The -w
lets the command being executed inside the current working directory, by
changing into the directory to the value returned by pwd. So this
combination executes the command using the container, but inside the
current working directory.
$ sudo docker run -v /doesnt/exist:/foo -w /foo -i -t ubuntu bash
When the host directory of a bind-mounted volume doesn't exist, Docker
will automatically create this directory on the host for you. In the
example above, Docker will create the /doesnt/exist
folder before starting your container.
$ sudo docker run -t -i -v /var/run/docker.sock:/var/run/docker.sock -v ./static-docker:/usr/bin/docker busybox sh
By bind-mounting the docker unix socket and statically linked docker binary (such as that provided by https://get.docker.io), you give the container the full access to create and manipulate the host's docker daemon.
$ sudo docker run -p 127.0.0.1:80:8080 ubuntu bash
This binds port 8080 of the container to port 80 on 127.0.0.1 of
the host machine. The Docker User Guide
explains in detail how to manipulate ports in Docker.
$ sudo docker run --expose 80 ubuntu bash
This exposes port 80 of the container for use within a link without
publishing the port to the host system's interfaces. The Docker User
Guide explains in detail how to manipulate
ports in Docker.
$ sudo docker run -e MYVAR1 --env MYVAR2=foo --env-file ./env.list ubuntu bash
This sets environmental variables in the container. For illustration all three
flags are shown here. Where -e, --env take an environment variable and
value, or if no "=" is provided, then that variable's current value is passed
through (i.e. $MYVAR1 from the host is set to $MYVAR1 in the container). All
three flags, -e, --env and --env-file can be repeated.
Regardless of the order of these three flags, the --env-file are processed
first, and then -e, --env flags. This way, the -e or --env will
override variables as needed.
$ cat ./env.list
TEST_FOO=BAR
$ sudo docker run --env TEST_FOO="This is a test" --env-file ./env.list busybox env | grep TEST_FOO
TEST_FOO=This is a test
The --env-file flag takes a filename as an argument and expects each line
to be in the VAR=VAL format, mimicking the argument passed to --env. Comment
lines need only be prefixed with #
An example of a file passed with --env-file
$ cat ./env.list
TEST_FOO=BAR
# this is a comment
TEST_APP_DEST_HOST=10.10.0.127
TEST_APP_DEST_PORT=8888
# pass through this variable from the caller
TEST_PASSTHROUGH
$ sudo TEST_PASSTHROUGH=howdy docker run --env-file ./env.list busybox env
HOME=/
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=5198e0745561
TEST_FOO=BAR
TEST_APP_DEST_HOST=10.10.0.127
TEST_APP_DEST_PORT=8888
TEST_PASSTHROUGH=howdy
$ sudo docker run --name console -t -i ubuntu bash
This will create and run a new container with the container name being
console.
$ sudo docker run --link /redis:redis --name console ubuntu bash
The --link flag will link the container named /redis into the newly
created container with the alias redis. The new container can access the
network and environment of the redis container via environment variables.
The --name flag will assign the name console to the newly created
container.
$ sudo docker run --volumes-from 777f7dc92da7 --volumes-from ba8c0c54f0f2:ro -i -t ubuntu pwd
The --volumes-from flag mounts all the defined volumes from the referenced
containers. Containers can be specified by repetitions of the --volumes-from
argument. The container ID may be optionally suffixed with :ro or :rw to
mount the volumes in read-only or read-write mode, respectively. By default,
the volumes are mounted in the same mode (read write or read only) as
the reference container.
The -a flag tells docker run to bind to the container's STDIN, STDOUT or
STDERR. This makes it possible to manipulate the output and input as needed.
$ echo "test" | sudo docker run -i -a stdin ubuntu cat -
This pipes data into a container and prints the container's ID by attaching
only to the container's STDIN.
$ sudo docker run -a stderr ubuntu echo test
This isn't going to print anything unless there's an error because we've
only attached to the STDERR of the container. The container's logs
still store what's been written to STDERR and STDOUT.
$ cat somefile | sudo docker run -i -a stdin mybuilder dobuild
This is how piping a file into a container could be done for a build.
The container's ID will be printed after the build is done and the build
logs could be retrieved using docker logs. This is
useful if you need to pipe a file or something else into a container and
retrieve the container's ID once the container has finished running.
$ sudo docker run --device=/dev/sdc:/dev/xvdc --device=/dev/sdd --device=/dev/zero:/dev/nulo -i -t ubuntu ls -l /dev/{xvdc,sdd,nulo} brw-rw---- 1 root disk 8, 2 Feb 9 16:05 /dev/xvdc brw-rw---- 1 root disk 8, 3 Feb 9 16:05 /dev/sdd crw-rw-rw- 1 root root 1, 5 Feb 9 16:05 /dev/nulo
It is often necessary to directly expose devices to a container. --device
option enables that. For example, a specific block storage device or loop
device or audio device can be added to an otherwise unprivileged container
(without the --privileged flag) and have the application directly access it.
** Security note: **
--device cannot be safely used with ephemeral devices. Block devices that may be removed should not be added to untrusted containers with --device!
A complete example:
$ sudo docker run -d --name static static-web-files sh
$ sudo docker run -d --expose=8098 --name riak riakserver
$ sudo docker run -d -m 100m -e DEVELOPMENT=1 -e BRANCH=example-code -v $(pwd):/app/bin:ro --name app appserver
$ sudo docker run -d -p 1443:443 --dns=10.0.0.1 --dns-search=dev.org -v /var/log/httpd --volumes-from static --link riak --link app -h www.sven.dev.org --name web webserver
$ sudo docker run -t -i --rm --volumes-from web -w /var/log/httpd busybox tail -f access.log
This example shows 5 containers that might be set up to test a web application change:
- Start a pre-prepared volume image
static-web-files(in the background) that has CSS, image and static HTML in it, (with aVOLUMEinstruction in the Dockerfile to allow the web server to use those files); - Start a pre-prepared
riakserverimage, give the container nameriakand expose port8098to any containers that link to it; - Start the
appserverimage, restricting its memory usage to 100MB, setting two environment variablesDEVELOPMENTandBRANCHand bind-mounting the current directory ($(pwd)) in the container in read-only mode as/app/bin; - Start the
webserver, mapping port443in the container to port1443on the Docker server, setting the DNS server to10.0.0.1and DNS search domain todev.org, creating a volume to put the log files into (so we can access it from another container), then importing the files from the volume exposed by thestaticcontainer, and linking to all exposed ports fromriakandapp. Lastly, we set the hostname toweb.sven.dev.orgso its consistent with the pre-generated SSL certificate; - Finally, we create a container that runs
tail -f access.logusing the logs volume from thewebcontainer, setting the workdir to/var/log/httpd. The--rmoption means that when the container exits, the container's layer is removed.
Restart Policies
Using the --restart flag on Docker run you can specify a restart policy for
how a container should or should not be restarted on exit.
** no ** - Do not restart the container when it exits.
** on-failure ** - Restart the container only if it exits with a non zero exit status.
** always ** - Always restart the container reguardless of the exit status.
You can also specify the maximum amount of times Docker will try to restart the container when using the ** on-failure ** policy. The default is that Docker will try forever to restart the container.
$ sudo docker run --restart=always redis
This will run the redis container with a restart policy of ** always ** so that if
the container exits, Docker will restart it.
$ sudo docker run --restart=on-failure:10 redis
This will run the redis container with a restart policy of ** on-failure ** and a
maximum restart count of 10. If the redis container exits with a non-zero exit
status more than 10 times in a row Docker will abort trying to restart the container.
Providing a maximum restart limit is only valid for the ** on-failure ** policy.
save
Usage: docker save [OPTIONS] IMAGE [IMAGE...]
Save an image(s) to a tar archive (streamed to STDOUT by default)
-o, --output="" Write to a file, instead of STDOUT
Produces a tarred repository to the standard output stream. Contains all parent layers, and all tags + versions, or specified repo:tag, for each argument provided.
It is used to create a backup that can then be used with docker load
$ sudo docker save busybox > busybox.tar
$ ls -sh busybox.tar
2.7M busybox.tar
$ sudo docker save --output busybox.tar busybox
$ ls -sh busybox.tar
2.7M busybox.tar
$ sudo docker save -o fedora-all.tar fedora
$ sudo docker save -o fedora-latest.tar fedora:latest
It is even useful to cherry-pick particular tags of an image repository
$ sudo docker save -o ubuntu.tar ubuntu:lucid ubuntu:saucy
search
Search Docker Hub for images
Usage: docker search [OPTIONS] TERM
Search the Docker Hub for images
--automated=false Only show automated builds
--no-trunc=false Don't truncate output
-s, --stars=0 Only displays with at least x stars
See Find Public Images on Docker Hub for more details on finding shared images from the command line.
start
Usage: docker start [OPTIONS] CONTAINER [CONTAINER...]
Restart a stopped container
-a, --attach=false Attach container's STDOUT and STDERR and forward all signals to the process
-i, --interactive=false Attach container's STDIN
When run on a container that has already been started, takes no action and succeeds unconditionally.
stop
Usage: docker stop [OPTIONS] CONTAINER [CONTAINER...]
Stop a running container by sending SIGTERM and then SIGKILL after a grace period
-t, --time=10 Number of seconds to wait for the container to stop before killing it. Default is 10 seconds.
The main process inside the container will receive SIGTERM, and after a grace period, SIGKILL
tag
Usage: docker tag [OPTIONS] IMAGE[:TAG] [REGISTRYHOST/][USERNAME/]NAME[:TAG]
Tag an image into a repository
-f, --force=false Force
You can group your images together using names and tags, and then upload them to Share Images via Repositories.
top
Usage: docker top CONTAINER [ps OPTIONS]
Display the running processes of a container
unpause
Usage: docker unpause CONTAINER
Unpause all processes within a container
The docker unpause command uses the cgroups freezer to un-suspend all
processes in a container.
See the [cgroups freezer documentation] (https://www.kernel.org/doc/Documentation/cgroups/freezer-subsystem.txt) for further details.
version
Usage: docker version
Show the Docker version information.
Show the Docker version, API version, Git commit, and Go version of both Docker client and daemon.
wait
Usage: docker wait CONTAINER [CONTAINER...]
Block until a container stops, then print its exit code.