Docker : Frequently Used Commands

Collection of frequently used docker commands

                

Command	Syntax	Example	Notes
Create Docker Container
Manually create a docker container	docker create <image name>	docker create hello-world
Start a created/stopped Container
Manually start a created / stopped docker container	docker start  -a <container id>		-a : watches the output from the container and prints on the console
Check the output logs during the manual start of the container	docker logs <containerid>		If -a is not specified in the start container command, the output will not be printed during start of the container. Logs command can be used to check the output after the container is started
Run Docker Containers
Run a image in a docker container	docker run <image name>	docker run hello-world	docker run =  docker create + docker start
Run a image in a docker container and keep the container running in the background	docker run -d <image name>	docker run -d hello-world
Run image in a container and execute a command in the started container	docker run <image name> <command>	docker run busybox echo hello   docker run busybox ls
Port forwarding the requests from local machine to the container	docker run -p <port number of localhost>:<port number of the container> <image name>	docker run -p 8080:8080 princearoraaws/simpleweb
List docker containers and resources
List the running docker containers	docker ps   docker container ls
List all the docker containers	docker ps –a   docker container ls -a		-a: Lists all the containers
List all container ids only	docker container ls -aq docker ps –aq		-q: List only container ids   -a: List all the containers
List docker volumes	docker volume ls
Stop docker containers
Stop all the running containers	docker container stop $(docker container ls -aq)
Stop the docker container	docker stop <container id>
Kil the docker container instance	docker kill <container id>
Prune / Remove docker containers and resources
Remove all unused containers, networks, images (both dangling and unreferenced), and optionally, volumes.	docker system prune -a -f --volumes		-f: Do not prompt for confirmation   --volumes: By default, the command doesn’t remove unused volumes to prevent losing important data. To remove all unused volumes, pass the --volumes option   -a: Remove all unused images not just dangling ones
Remove docker containers	docker rm <conrtainerID | container name>   docker container rm [OPTIONS] CONTAINER [CONTAINER...]	docker container rm zen_haslett	Docker containers are not automatically removed when you stop them unless you start the container using the --rm flag
Remove all stopped containers	docker container prune -f		To remove all stopped containers, invoke the docker container prune command   -f: Do not prompt for confirmation
Remove images	docker image prune docker image prune -a		A dangling image is an image that is not tagged and is not used by any container. To remove dangling images use image prune   -a : To remove all images that are not referenced by any existing container, not just the dangling ones, use the prune command with the -a option
Remove docker volumes	docker volume rm -f VOLUME		-f: Do not prompt for confirmation
Remove all unused local volumes	docker volume prune -f		-f: Do not prompt for confirmation
Remove one or more networks	docker network rm NETWORK [NETWORK...]		To remove a network, you must first disconnect any containers connected to it.
Remove all unused networks	docker network prune -f		Unused networks are those which are not referenced by any containers.
Execute Commands In Docker Container
Execute a command inside a running docker container	docker exec -it <container id> <command>		-it: allows to provide input to the container. -i: input you type will be directed to standard IN of cli. Keep STDIN open even if not attached -t:All the text you type will be user friendly formatted terminal. Allocate a pseudo-TT
Opens the shell prompt of the running container	docker exec -it <container id> sh
Get into the shell prompt inside the container while starting the container	docker run -it <image name> sh	docker run -it busybox sh	When you specify command while running the run , the defaut command specified by the image is not executed
Run tests on a running container	docker run exec -it <containerid> npm run test
DockerFile
Build the Dockerfile to generate an image	docker build .		"." represents the build context. Build context is a set of files and folders belonging to our project which we want to encapsulate in the container
*Note : When using a Dockerfile, the container will use the cached images instead of doing the entire build process again in subsequent builds. In case a RUN command is changed, or a new RUN command is added in the dockerfile, this will cause docker to run the build process again for the changed/added step and all the steps after that line.   Even if the sequence of steps is changed, docker will execute the build process from the changed line and all the subsequent steps   If any changes are required in the steps, the change should be put down as far as possible.
Build the Dockerfile to generate an image with name of dockerfile specified	docker build -f <docker file name> .		Dockerfile.dev --> development version
Tagging an image during build	docker build -t <dockerid>/<repo/project name>:<version> .
Manually taking snapshot of a running docker container	docker commit -c "CMD '<default command of the new image>'" <container id>   docker run <image id>	docker commit -c "CMD 'redis-server'" <container id>	Create a new image from a container’s changes. Commit a container’s file changes or settings into a new image
Multi Step Docker Build - Production Dockerfile	FROM node:alpine WORKDIR '/app' COPY package.json . RUN npm install COPY . . RUN npm run build   FROM nginx COPY --from=0 /app/build /usr/share/nginx/html
docker-compose commands
Run an image in a container	docker-compose up
Build the image and run in a container	docker-compose up --build
Run an image in a container in background	docker-compose up -d
Stop containers	docker-compose down
List the containers started by docker-compose	docker-compose ps		Should be run from the directory containing the docker-compose file
Mount Docker Volumes
Mount docker volumes for hot deployment	docker run -it -p <localhostport>:<containerport> -v <container directories not to be mapped to any folder> -v <localhost workdir  to be mapped>:<Container WORKDIR to be mapped> -e CHOKIDAR_USEPOLLING=true <imageid>	docker run -it --rm -p 5000:3000 -v /app/node_modules -v ${pwd}:/app -e CHOKIDAR_USEPOLLING=true princearoraaws/frontend
Docker Image Commands
Pull docker image	docker pull <image id>
Print out the steps used to create the nginx image	docker history < image id>	docker history nginx
Return low-level information on Docker objects	docker inspect [OPTIONS] NAME|ID [NAME|ID...]