In this section, we will explore how to manage Docker images effectively. Docker images are the building blocks of containers, and managing them efficiently is crucial for maintaining a streamlined and organized development environment.

1. Listing Docker Images
2. Removing Docker Images
3. Pruning Unused Images
4. Inspecting Docker Images
5. Saving and Loading Docker Images
6. Importing and Exporting Docker Images

To list all the Docker images available on your system, you can use the docker images command.

• REPOSITORY: The name of the repository.
• TAG: The tag of the image.
• IMAGE ID: The unique identifier for the image.
• CREATED: The time when the image was created.
• SIZE: The size of the image.

To remove a Docker image, use the docker rmi command followed by the image ID or repository:tag.

• This command removes the ubuntu:latest image from your system.

To remove all unused images (dangling images), you can use the docker image prune command.

• This command removes all dangling images, which are images that are not tagged and not referenced by any container.

To remove all unused images, not just dangling ones, use the --all or -a flag.

To get detailed information about a Docker image, use the docker inspect command followed by the image ID or repository:tag.

• This command provides detailed JSON output about the image, including its layers, configuration, and more.

To save a Docker image to a tar archive, use the docker save command.

• This command saves the ubuntu:latest image to a file named ubuntu_latest.tar.

To load a Docker image from a tar archive, use the docker load command.

• This command loads the image from the ubuntu_latest.tar file into your Docker environment.

To export a Docker image to a tar archive, use the docker export command. Note that this command is typically used for containers, not images.

• This command exports the filesystem of the container mycontainer to a file named mycontainer.tar.

To import a Docker image from a tar archive, use the docker import command.

• This command imports the filesystem from mycontainer.tar and creates a new image named mynewimage:latest.

1. List all Docker images on your system.
2. Remove an image by its ID.
3. Prune all unused images.
4. Inspect an image to view its detailed information.
5. Save an image to a tar archive.
6. Load an image from a tar archive.

1. List all Docker images:

   docker images
   

2. Remove an image by its ID:

   docker rmi <IMAGE_ID>
   

3. Prune all unused images:

   docker image prune -a
   

4. Inspect an image:

   docker inspect <IMAGE_ID>
   

5. Save an image to a tar archive:

   docker save -o myimage.tar <IMAGE_NAME>:<TAG>
   

6. Load an image from a tar archive:

   docker load -i myimage.tar
   

• Mistake: Trying to remove an image that is being used by a running container.

  • Tip: Stop and remove the container before removing the image.

• Mistake: Forgetting to use the -a flag with docker image prune to remove all unused images.

  • Tip: Use docker image prune -a to ensure all unused images are removed.

• Mistake: Confusing docker save/docker load with docker export/docker import.

  • Tip: Use docker save/docker load for images and docker export/docker import for containers.

In this section, we covered the essential commands and practices for managing Docker images. You learned how to list, remove, prune, inspect, save, load, export, and import Docker images. These skills are fundamental for maintaining a clean and efficient Docker environment. In the next section, we will dive into Docker containers and explore how to run and manage them effectively.