Basic Docker Commands 2024

Basic Docker Commands 2024

Here are some essential Docker commands, along with examples and explanations for each:

1. docker --version

• Description: Displays the Docker version installed on the system.

• Example:
  

   docker --version
  

• Output:
  

   Docker version 20.10.7, build f0df350
  

• Explanation: Helps verify if Docker is installed and check the version for compatibility with specific features or projects.

  ---

2. docker pull

• Description: Downloads a Docker image from a remote registry (Docker Hub by default) to your local system.

• Example:
  

   docker pull nginx
  

• Explanation: Downloads the official NGINX image to your local machine. Docker will fetch the image from Docker Hub if it is not available locally.

  ---

3. docker images

• Description: Lists all the Docker images available locally.

• Example:
  

   docker images
  

• Output:
  

   REPOSITORY  TAG     IMAGE ID      CREATED      SIZE
   nginx       latest  ae2feff98a0c  2 weeks ago  133MB
  

• Explanation: Shows all downloaded or built images with details such as repository, tag, image ID, creation date, and size.

  ---

4. docker run

• Description: Runs a container from an image. It creates, starts, and runs the container from a specified image.

• Example:
  

   docker run -d -p 8080:80 nginx
  

• Explanation:

  • -d: Runs the container in detached mode (in the background).
  • -p 8080:80: Maps the container's port 80 to the host machine's port 8080.
  • This command will run an NGINX container and serve it on your local machine at localhost:8080.

---

5. docker ps

• Description: Lists all running containers.

• Example:
  

   docker ps
  

• Output:
  

   CONTAINER ID  IMAGE   COMMAND       CREATED     STATUS     PORTS                    NAMES
   87dfb6cf56d2  nginx   "/docker-e..."  5 minutes  Up 5 mins  0.0.0.0:8080->80/tcp     amazing_elion
  

• Explanation: Displays all active containers along with information like container ID, image used, running status, and mapped ports.

  ---

6. docker stop

• Description: Stops a running container.

• Example:
  

   docker stop 87dfb6cf56d2
  

• Explanation: Stops the container with the ID 87dfb6cf56d2. You can also use the container name instead of the ID.

  ---

7. docker rm

• Description: Removes a stopped container.

• Example:
  

   docker rm 87dfb6cf56d2
  

• Explanation: Removes the container from the Docker system. The container must be stopped first. You can use the container ID or name.

  ---

8. docker rmi

• Description: Removes a Docker image from your local system.

• Example:
  

   docker rmi nginx
  

• Explanation: Deletes the image nginx from the local machine. If any containers are using this image, you must stop and remove them first.

  ---

9. docker exec

• Description: Runs a command inside a running container.

• Example:
  

   docker exec -it 87dfb6cf56d2 /bin/bash
  

• Explanation: Opens an interactive shell (/bin/bash) inside the running container. The -it option makes the session interactive, allowing you to execute commands within the container.

  ---

10. docker logs

• Description: Displays the logs from a running or stopped container.

• Example:
  

   docker logs 87dfb6cf56d2
  

• Explanation: Fetches the logs for the container with the specified ID, showing output generated by the application running inside the container.

  ---

11. docker build

• Description: Builds an image from a Dockerfile.

• Example:
  

   docker build -t myapp .
  

• Explanation: The -t flag assigns a tag (myapp) to the image. The . specifies the build context (usually the current directory where the Dockerfile is located).

  ---

12. docker inspect

• Description: Returns detailed information about a container or image.

• Example:
  

   docker inspect 87dfb6cf56d2
  

• Explanation: Outputs a JSON object containing low-level details about the specified container or image, such as network settings, mounts, and configuration.

  ---

13. docker-compose up

• Description: Starts containers as defined in a docker-compose.yml file.

• Example:
  

   docker-compose up
  

• Explanation: Spins up all services defined in the docker-compose.yml file, creating containers, networks, and volumes as needed.

  ---

14. docker-compose down

• Description: Stops and removes containers, networks, and volumes created by docker-compose up.

• Example:
  

   docker-compose down
  

• Explanation: Cleans up resources used by the docker-compose setup, effectively bringing down the application stack.

Summary of Basic Docker Commands

These commands provide a foundation for working with Docker, covering common tasks such as managing images, containers, networks, logs, and executing commands.