# Docker and Podman ## Docker ### Installation Debian： ```bash apt-get install docker-engine ``` Red Hat： ```bash dnf install docker-engine ``` ### Images Pull image ```bash docker pull <namespace>/<name>:<tag> ``` :::info :bulb: If no tag is specified, docker will pull the latest version of the image. That is： `docker pull ubuntu`is equivalent to `docker pull ubuntu:latest` ::: List images ```bash docker images ``` Inspect docker image ```bash docker inspect <image> ``` Remove Images ```bash docker rmi <image> ``` Save Images ```bash docker save -o <tarfile> <image> ``` Load Images ```bash docker load -i <tarfile> ``` ### Containers Run a container from image ```bash docker run -it [-d] [--name <name>] <image> [<command>] ``` Start a stopped container ```bash docker start <container> ``` Stop a container ```bash docker stop [-t] <container> ``` Pause a container ```bash docker pause <container> ``` Unpause a container ```bash docker unpause <container> ``` List Running Containers ```bash docker ps ``` List All Containers ```bash docker ps -a ``` List Recent Container ```bash docker ps -l docker ps -n <number> ``` List Containers Using filters ```bash docker ps -f <key=vlaue> docker ps -f "name=nginx" ``` View output ```bash docker logs <container> [--tail <n>] [--since <timestamp>] [-f] ``` Attach and enter a daemon container ```bash docker attach <container> ``` Execute command in a container ```bash docker exec [-d] <container> <command> ``` Send signal ```bash docker kill [-s <signal>] <container> ``` Commit a container's file changes into a new image ```bash docker commit -m <"message"> <container> <image> ``` Export a container ```bash docker export -o <tarfile> <container> ``` ## Data Volume ### Concepts * Preferred mechanism for **persistent data storage** Docker containers. * Volumes can be more shared among multiple containers. * The contents of a volume exists outside of the lifecycle of a container. ![](https://i.imgur.com/OlSKWmj.png) ### Command We can mount the data volume to a container by adding `-v <data volume name>:<destination>` / `-v <source directory>:<destination>` or ` --mount source=<volume>,target=<destination>`. :::info when using `docker service`, `-v` is not supported. We can only use `--mount`. ::: Alternatively, we can manually create a data volume using the following command: ```bash docker volume create [--name <data volume name>] ``` List all volumes: ```bash docker volume ls ``` Inspect some basic properties of a volume. ```bash docker volume inspect <volume> ``` Remove a volume ```bash docker volume rm <volume> ``` Remove container along with volume ```bash docker rm -v <volume> ``` :::info Named volume will not be deleted using `-v` command. ::: Read only volumes Add `-v <volume>:<destination>:ro` or `--mount source=<volume>,destination=<destination>,readonly` ### Data container Example: Create a data container ```bash docker create --name data -v /data ubuntu ``` Connect container to data container ```bash docker run --name container1 --volumes-from data nginx ``` ## Docker Networking ### Network drivers 1. **bridge**: The default driver. Usually used when containers need to communicate with other containers <u>running on the same docker host</u>. ## Dockerfile