Basic Commands

Run a container

docker run <image-name>:<version>

List containers

docker ps

List all running as well as previously stopped containers.

docker ps -a

Stop a container

docker stop <container-name-or-id> 

Remove a container

docker rm <container-name-or-id> 

Remove all containers at once

docker rm $(docker ps -aq)

List images

docker images 

Remove images

You should be ensure the container is not running using this image.

docker rmi <image-name>

Remove an image if there are multiple versions available

docker rmi <repository-name>:<version>

Pull the image

Pulls nginx image without run.

docker pull nginx 

Run containers for a while

Some containers don't run forever. For ex: ubuntu image.
Run a container for a 5 seconds.

docker run ubuntu sleep 5

Execute a command inside the container

Prints the etc/hosts file inside the container

docker exec <container-name-or-id> cat /etc/hosts 

Run container attach mode

docker run <container-name-or-id>

Run container detach mode

docker run -d <container-name-or-id>

Docker Run Commands

Run a container based on an image and give it a explicit name

docker run --name <explicit-name> <image-name>

Port mapping

This command maps traffic comes from port 80 to 5000 port in docker host. We can also create more instances on the same container

docker run -p 80:5000 redis

Volume mapping

This command mounts the var/lib/mysql folder to the /opt/datadir folder which exist in the docker host.

docker run -v /opt/datadir:/var/lib/mysql mysql

More info about container

docker inspect <container-name-or-id>

Container logs

docker logs <container-name-or-id>

Run a command remote machine

docker -H=remote-docker-engine:2375

Docker Images

Build docker file

docker build . -f Dockerfile -t <image-name>

Push image to registry

docker push <image-name>

Environment Variables

We can pass an environment variable to the source code lives in container.

docker run -e ENV-VAR-NAME=value <image-name>

We can now inspect the variable with:

docker inspect <container-name-or-id>

Docker Compose

docker compose up

Docker Network

docker network

Create a new network named wp-mysql-network using the bridge driver. Allocate subnet 182.18.0.1/24. Configure Gateway 182.18.0.1

docker network create --driver bridge --subnet 182.18.0.1/24 --gateway 182.18.0.1 wp-mysql-network

Deploy a mysql database using the mysql:5.6 image and name it mysql-db. Attach it to the newly created network wp-mysql-network Set the database password to use db_pass123. The environment variable to set is MYSQL_ROOT_PASSWORD

docker run -d -e MYSQL_ROOT_PASSWORD=db_pass123 --name mysql-db --network wp-mysql-network mysql:5.6