Memento Docker

1. Basic Docker Commands

Check Docker Version
docker --version
- Displays the installed Docker version.

Check Docker Info
docker info
- Displays detailed information about the Docker installation, including container and image counts.

List All Running Containers
docker ps
- Lists all currently running containers.

List All Containers (Including Stopped)
docker ps -a
- Lists all containers, including those that are stopped.

List All Docker Images
docker images
- Displays all Docker images present locally.

2. Managing Docker Containers

Run a Container from an Image
docker run <image-name>
- Runs a container from a specified image.

Run a Container in Detached Mode
docker run -d <image-name>
- Runs the container in the background (detached mode).

Run a Container with Interactive Terminal
docker run -it <image-name> /bin/bash
- Runs the container with an interactive terminal and opens a bash shell.

Run a Container with Port Mapping
docker run -p 8080:80 <image-name>
- Maps port 8080 on the host to port 80 inside the container.

Stop a Running Container
docker stop <container-id>
- Stops a running container.

Start a Stopped Container
docker start <container-id>
- Starts a container that has been stopped.

Restart a Container
docker restart <container-id>
- Restarts a running or stopped container.

Remove a Container
docker rm <container-id>
- Removes a stopped container from your system.

3. Managing Docker Images

Pull an Image from Docker Hub
docker pull <image-name>
- Downloads a Docker image from Docker Hub or another registry.

Build an Image from a Dockerfile
docker build -t <image-name> <path>
- Builds a Docker image from the specified Dockerfile located at the given path.

Tag an Image
docker tag <image-name> <new-image-name>
- Tags an existing image with a new name.

Remove an Image
docker rmi <image-name>
- Removes a Docker image from your local system.

4. Docker Volumes

List All Volumes
docker volume ls
- Lists all Docker volumes on your system.

Create a New Volume
docker volume create <volume-name>
- Creates a new volume.

Remove a Volume
docker volume rm <volume-name>
- Removes a volume from your system.

Mount a Volume to a Container
docker run -v <volume-name>:/path/in/container <image-name>
- Mounts a volume to a specific path inside the container.

5. Networking

Understanding Docker Networks
Docker creates default networks (bridge, host, none). List them with:
docker network ls

Create a Custom Network
docker network create my-network
- Isolate containers for secure communication.

Attach a Container to a Network
docker run -d --name my-nginx --net my-network nginx
- Launches an Nginx container on the custom network.

6. Using GitLab Docker Registry

Log in to GitLab Registry
docker login registry.gitlab.com
- Authenticate with your GitLab credentials or a personal access token.

Tag and Push an Image
docker build -t registry.gitlab.com/your-project/image:tag .
docker push registry.gitlab.com/your-project/image:tag
- Builds and uploads the image to GitLab’s registry.

Pull an Image
docker pull registry.gitlab.com/your-project/image:tag
- Retrieves the image for local use.

CI/CD Authentication
In .gitlab-ci.yml, use:
docker login -u $CI_REGISTRY_USER -p $CI_JOB_TOKEN $CI_REGISTRY
- Automates registry access during pipelines.

Last update : 2025-05-04T18:47:58Z