Useful Docker Commands

Here are Docker commands I use frequently while maintaining containers.

Add a host entry : ```shell docker run --add-host="localA:127.0.0.1"

List images
: ```shell
docker images

Build an image : ```shell docker build -t docker-whale .

The command uses the `Dockerfile` in the current directory and builds an image named `docker-whale`.

Remove an image
: ```shell
docker rmi

Remove a container : ```shell docker rm

Common `docker run` flags
: 
- `-t` assigns a pseudo-tty.
- `-i` keeps STDIN open for interactive use.
- `-d` runs in the background.
- `-P` maps exposed ports to the host.

Add port mapping to a running container
: ```shell
docker port jolly_sinoussi 5000 0.0.0.0:80

List running containers : ```shell docker ps

List all containers
: ```shell
docker ps -a

Restart a container : ```shell docker restart

View container logs (stdout/stderr)
: ```shell
docker logs

Inspect container configuration : ```shell docker inspect

Commit a container to an image
: ```shell
docker commit containerid image_id

Exec into a running container : ```shell docker exec -ti <docker_name> /bin/bash

Or

docker attach

Export an image
: ```shell
docker save myimage:latest | gzip > myimage_latest.tar.gz

Import an image : ```shell docker load -i myimage_latest.tar.gz

Or

docker load < myimage_latest.tar.gz

Prune unused data
: ```shell
docker system prune

This removes stopped containers, unused volumes and networks, and dangling images.

docker system prune -a

The -a option removes all unused images, even those with tags.

Export all tagged images : ```shell docker save $(docker images --format '{{.Repository}}:{{.Tag}}') -o allinone.tar

Mount a local folder
: ```shell
-v /src/webapp:/dst/webapp

Restart policy : ```shell --restart always/unless-stopped/no/on-failure

Reference: [Docker documentation](https://docs.docker.com/engine/tutorials/usingdocker/)