# Docker cheat sheet ### Check Version * [`docker version`](https://docs.docker.com/engine/reference/commandline/version/) shows which version of docker you have running. ### Containers #### Lifecycle * [`docker create`](https://docs.docker.com/engine/reference/commandline/create) creates a container but does not start it. * [`docker rename`](https://docs.docker.com/engine/reference/commandline/rename/) allows the container to be renamed. * [`docker run`](https://docs.docker.com/engine/reference/commandline/run) creates and starts a container in one operation. * [`docker rm`](https://docs.docker.com/engine/reference/commandline/rm) deletes a container. * [`docker update`](https://docs.docker.com/engine/reference/commandline/update/) updates a container's resource limits. #### Starting and Stopping * [`docker start`](https://docs.docker.com/engine/reference/commandline/start) starts a container so it is running. * [`docker stop`](https://docs.docker.com/engine/reference/commandline/stop) stops a running container. * [`docker restart`](https://docs.docker.com/engine/reference/commandline/restart) stops and starts a container. * [`docker pause`](https://docs.docker.com/engine/reference/commandline/pause/) pauses a running container, "freezing" it in place. * [`docker unpause`](https://docs.docker.com/engine/reference/commandline/unpause/) will unpause a running container. * [`docker wait`](https://docs.docker.com/engine/reference/commandline/wait) blocks until running container stops. * [`docker kill`](https://docs.docker.com/engine/reference/commandline/kill) sends a SIGKILL to a running container. * [`docker attach`](https://docs.docker.com/engine/reference/commandline/attach) will connect to a running container. #### **CPU Constraints** You can limit CPU, either using a percentage of all CPUs, or by using specific cores. For example, you can tell the [`cpu-shares`](https://docs.docker.com/engine/reference/run/#/cpu-share-constraint) setting. The setting is a bit strange -- 1024 means 100% of the CPU, so if you want the container to take 50% of all CPU cores, you should specify 512: ``` docker run -it -c 512 agileek/cpuset-test ``` You can also only use some CPU cores using [`cpuset-cpus`](https://docs.docker.com/engine/reference/run/#/cpuset-constraint)`:` ``` docker run -it --cpuset-cpus=0,4,6 agileek/cpuset-test ``` > Note that Docker can still **see** all of the CPUs inside the container -- it just isn't using all of them. **Memory Constraints** You can also set [memory constraints](https://docs.docker.com/engine/reference/run/#/user-memory-constraints) on Docker: ``` docker run -it -m 300M ubuntu:14.04 /bin/bash ``` #### Info * [`docker ps`](https://docs.docker.com/engine/reference/commandline/ps) shows running containers. * [`docker logs`](https://docs.docker.com/engine/reference/commandline/logs) gets logs from container. * [`docker inspect`](https://docs.docker.com/engine/reference/commandline/inspect) looks at all the info on a container (including IP address). * [`docker events`](https://docs.docker.com/engine/reference/commandline/events) gets events from container. * [`docker port`](https://docs.docker.com/engine/reference/commandline/port) shows public facing port of container. * [`docker top`](https://docs.docker.com/engine/reference/commandline/top) shows running processes in container. * [`docker stats`](https://docs.docker.com/engine/reference/commandline/stats) shows containers' resource usage statistics. * [`docker diff`](https://docs.docker.com/engine/reference/commandline/diff) shows changed files in the container's FS. #### Import / Export * [`docker cp`](https://docs.docker.com/engine/reference/commandline/cp) copies files or folders between a container and the local filesystem. * [`docker export`](https://docs.docker.com/engine/reference/commandline/export) turns container filesystem into tarball archive stream to STDOUT. #### Import/Export container Import a container as an image from file: ``` cat my_container.tar.gz | docker import - my_image:my_tag ``` Export an existing container: ``` docker export my_container | gzip > my_container.tar.gz ``` #### Executing Commands * [`docker exec`](https://docs.docker.com/engine/reference/commandline/exec) to execute a command in container. ### Images #### Lifecycle * [`docker images`](https://docs.docker.com/engine/reference/commandline/images) shows all images. * [`docker import`](https://docs.docker.com/engine/reference/commandline/import) creates an image from a tarball. * [`docker build`](https://docs.docker.com/engine/reference/commandline/build) creates image from Dockerfile. * [`docker commit`](https://docs.docker.com/engine/reference/commandline/commit) creates image from a container, pausing it temporarily if it is running. * [`docker rmi`](https://docs.docker.com/engine/reference/commandline/rmi) removes an image. * [`docker load`](https://docs.docker.com/engine/reference/commandline/load) loads an image from a tar archive as STDIN, including images and tags (as of 0.7). * [`docker save`](https://docs.docker.com/engine/reference/commandline/save) saves an image to a tar archive stream to STDOUT with all parent layers, tags & versions (as of 0.7). #### Info * [`docker history`](https://docs.docker.com/engine/reference/commandline/history) shows history of image. * [`docker tag`](https://docs.docker.com/engine/reference/commandline/tag) tags an image to a name (local or registry). #### Load/Save image Load an image from file: ``` docker load < my_image.tar.gz ``` Save an existing image: ``` docker save my_image:my_tag | gzip > my_image.tar.gz ``` ### Dockerfile #### Instructions * [.dockerignore](https://docs.docker.com/engine/reference/builder/#dockerignore-file) * [FROM](https://docs.docker.com/engine/reference/builder/#from) Sets the Base Image for subsequent instructions. * [MAINTAINER (deprecated - use LABEL instead)](https://docs.docker.com/engine/reference/builder/#maintainer-deprecated) Set the Author field of the generated images. * [RUN](https://docs.docker.com/engine/reference/builder/#run) execute any commands in a new layer on top of the current image and commit the results. * [CMD](https://docs.docker.com/engine/reference/builder/#cmd) provide defaults for an executing container. * [EXPOSE](https://docs.docker.com/engine/reference/builder/#expose) informs Docker that the container listens on the specified network ports at runtime. NOTE: does not actually make ports accessible. * [ENV](https://docs.docker.com/engine/reference/builder/#env) sets environment variable. * [ADD](https://docs.docker.com/engine/reference/builder/#add) copies new files, directories or remote file to container. Invalidates caches. Avoid `ADD` and use `COPY` instead. * [COPY](https://docs.docker.com/engine/reference/builder/#copy) copies new files or directories to container. By default this copies as root regardless of the USER/WORKDIR settings. Use `--chown=:` to give ownership to another user/group. (Same for `ADD`.) * [ENTRYPOINT](https://docs.docker.com/engine/reference/builder/#entrypoint) configures a container that will run as an executable. * [VOLUME](https://docs.docker.com/engine/reference/builder/#volume) creates a mount point for externally mounted volumes or other containers. * [USER](https://docs.docker.com/engine/reference/builder/#user) sets the user name for following RUN / CMD / ENTRYPOINT commands. * [WORKDIR](https://docs.docker.com/engine/reference/builder/#workdir) sets the working directory. * [ARG](https://docs.docker.com/engine/reference/builder/#arg) defines a build-time variable. * [ONBUILD](https://docs.docker.com/engine/reference/builder/#onbuild) adds a trigger instruction when the image is used as the base for another build. * [STOPSIGNAL](https://docs.docker.com/engine/reference/builder/#stopsignal) sets the system call signal that will be sent to the container to exit. * [LABEL](https://docs.docker.com/config/labels-custom-metadata/) apply key/value metadata to your images, containers, or daemons. * [SHELL](https://docs.docker.com/engine/reference/builder/#shell) override default shell is used by docker to run commands. * [HEALTHCHECK](https://docs.docker.com/engine/reference/builder/#healthcheck) tells docker how to test a container to check that it is still working. ### Registry & Repository * [`docker login`](https://docs.docker.com/engine/reference/commandline/login) to login to a registry. * [`docker logout`](https://docs.docker.com/engine/reference/commandline/logout) to logout from a registry. * [`docker search`](https://docs.docker.com/engine/reference/commandline/search) searches registry for image. * [`docker pull`](https://docs.docker.com/engine/reference/commandline/pull) pulls an image from registry to local machine. * [`docker push`](https://docs.docker.com/engine/reference/commandline/push) pushes an image to the registry from local machine. ### Volumes #### Lifecycle * [`docker volume create`](https://docs.docker.com/engine/reference/commandline/volume_create/) * [`docker volume rm`](https://docs.docker.com/engine/reference/commandline/volume_rm/) #### Info * [`docker volume ls`](https://docs.docker.com/engine/reference/commandline/volume_ls/) * [`docker volume inspect`](https://docs.docker.com/engine/reference/commandline/volume_inspect/) ### Networks #### Lifecycle * [`docker network create`](https://docs.docker.com/engine/reference/commandline/network_create/) NAME Create a new network (default type: bridge). * [`docker network rm`](https://docs.docker.com/engine/reference/commandline/network_rm/) NAME Remove one or more networks by name or identifier. No containers can be connected to the network when deleting it. #### Info * [`docker network ls`](https://docs.docker.com/engine/reference/commandline/network_ls/) List networks * [`docker network inspect`](https://docs.docker.com/engine/reference/commandline/network_inspect/) NAME Display detailed information on one or more networks. #### Connection * [`docker network connect`](https://docs.docker.com/engine/reference/commandline/network_connect/) NETWORK CONTAINER Connect a container to a network * [`docker network disconnect`](https://docs.docker.com/engine/reference/commandline/network_disconnect/) NETWORK CONTAINER Disconnect a container from a network . . . \------ --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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