Docker Documentation
Docker container — portable and can be shared containers with anyone.
It is not a virtual machine — carved up into different places.
Container — has everything that one needs to run the code in the container.
Networking, process code and each container has its own world and a web server which talks to the other container Docker is one which moniters it.
Docker — client program and as well as a server program which manages a running linux system. A program which builds its own code. A service which distributes docker.
Docker contains the docker code, node js and all installation of the image which one needs. This image designed on top of that machine and we can run as many containers as much processor and ram memory availabile. Build environment and we can run the environment anywhere.
Dockerhub and quay.io and any other machine can run the image.
Use the following command to check the running docker instances
Docker ps
- Use the following command to check the running and past running docker instances
Docker ps –a => -a option is able to show the hidden instances.
- Run the docker instance
docker run –it –-name <somename> -d Ubuntu
- Get the container id of the attached docker run.
docker ps –l
- Exit the container
exit
- Start the docker container
Docker start <container id>
- Attach the container id
docker attach <container id>
docker ps –l -> Gives the last exited docker container information
Commit the container containing the information
docker commit <container id>
docker tag <image id — one which gets printed post docker commit command> <image name>
Use command docker images to check which images are saved.
docker list containers which are exited
docker ps -aq -f status=exited
Remove Stopped Containers
docker ps -aq — no-trunc | xargs docker rm
This will not remove running containers
Remove dangling/untagged images
docker images -q — filter dangling=true | xargs docker rmi
Remove containers created after a specific container
docker ps — since a1bz3768ez7g -q | xargs docker rm
Remove containers created before a specific container
docker ps — before a1bz3768ez7g -q | xargs docker rm
Connect to same docker container
Docker exec -it <container id> bash
docker exec -ti — env COLUMNS=`tput cols` — env LINES=`tput lines` container id bash
In order to copy a file from a container to the host, you can use the command
docker cp <containerId>:/file/path/within/container /host/path/target
docker rmi -> docker remove images
