Docker List Images | Easy Guide to ‘docker images ls’ Command

In this comprehensive guide, we’ll explore one of Docker’s essential tools – the ‘docker images ls’ command. This seemingly simple command is a powerful ally in managing your Docker images. It’s your key to listing all your Docker images, offering a clear view of what’s available in your Docker environment.

But we’re not stopping at the basics. This post aims to guide you through the process of listing Docker images using the ‘docker images ls’ command and delve into the nuances of Docker image management.

By the end of this guide, you’ll master how to efficiently list and manage your Docker images, enhancing your overall Docker experience. So, let’s dive in and unravel the potential of the ‘docker images ls’ command.

TL;DR: What is the ‘docker images ls’ command?

The ‘docker images ls’ command is a fundamental tool in Docker that lists all your Docker images, providing a comprehensive view of what’s available in your Docker environment. It’s your first step towards efficient Docker image management. For more advanced methods, background, tips and tricks, continue reading the article.

Here is an example output when you execute the command docker images ls:

root:~$ docker images ls
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
my_app              latest              d4a0cbc60900        3 hours ago         132MB
ubuntu              16.04               c6a43cd4801e        2 weeks ago         131MB
nginx               latest              ea464350bb3e        3 weeks ago         121MB
mongo               4.0                 366218183055        3 months ago        381MB
redis               latest              234jkk432tae        5 months ago        95MB

Docker Images ls

The ‘docker images ls’ command is a fundamental part of Docker’s command-line interface (CLI). It’s the command that gives you a bird’s eye view of all your Docker images. When you run this command, Docker lists all the images that are currently available in your Docker environment. It’s your first stop in Docker image management.

‘docker images ls’ Output

When you run the ‘docker images ls’ command, you’ll see a table with several columns. Each column gives you a different piece of information about each Docker image. Here’s a breakdown of what each column represents:

• REPOSITORY: This column shows you the name of the image.
• TAG: This is the tag of the image. It’s like a version for your Docker image.
• IMAGE ID: This is the unique identifier for each Docker image.
• CREATED: This column tells you when the image was created.
• SIZE: This column shows you the size of the image.

Filtering Docker Images

Let’s say you have a lot of Docker images, and you want to filter them for a specific attribute. This is where filters come into play. You can use filters with the ‘docker images ls’ command to refine the list of Docker images. For example, you can filter images based on their name, tag, or even their size.

Example of using filters with ‘docker images ls’:

root:~$ docker images ls --filter=reference='*latest*'
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
my_app              latest              d4a0cbc60900        3 hours ago         132MB
nginx               latest              ea464350bb3e        3 weeks ago         121MB
redis               latest              234jkk432tae        5 months ago        95MB

In the output above, the docker images ls --filter=reference='*latest*' command lists only the Docker images that have a tag of “latest”.

Docker Registry API: A Step Beyond Docker CLI

As you gain proficiency with Docker and begin to explore its advanced features, you’ll encounter the Docker Registry API.

The Docker Registry API is a RESTful API that empowers you to manage your Docker images and registries programmatically. This means you can create, list, delete, and manage Docker images using HTTP requests, a powerful tool for automating Docker tasks and integrating Docker with other systems.

‘docker images ls’ vs. Docker Registry API: A Comparison

The ‘docker images ls’ command and the Docker Registry API both enable you to list Docker images, but they do so in distinct ways. The ‘docker images ls’ command is a CLI command that provides a quick and straightforward way to list Docker images in your Docker environment.

In contrast, the Docker Registry API is a programmable interface that offers more flexibility and control, allowing you to list Docker images (and perform other Docker tasks) programmatically.

API Endpoints: The Powerhouses of Listing and Managing Images

The Docker Registry API provides various endpoints that you can use to list and manage your Docker images. For example, you can use the ‘/v2/_catalog’ endpoint to list all the repositories in a registry, or the ‘/v2/{name}/tags/list’ endpoint to list all the tags for a specific repository.

Here’s how you can list all the repositories in a registry using the Docker Registry API:

curl -X GET https://<your-registry>/v2/_catalog

And here’s how you can list all the tags for a specific repository:

curl -X GET https://<your-registry>/v2/<repository>/tags/list

This command will list all the tags for the specified repository in your registry.

curl -X GET https://<your-registry>/v2/_catalog

The Role of APIs in the Docker Ecosystem

APIs hold a significant role in the Docker ecosystem, offering a programmable interface to Docker’s features and functionalities. They enable you to automate Docker tasks, integrate Docker with other systems, and create custom Docker tools and applications.

The Docker Registry API is just one of the many APIs that Docker provides, and understanding it can significantly enhance your Docker operations.

So, as you deepen your understanding of Docker and start exploring its advanced features, remember to consider the Docker Registry API. It’s a powerful tool that can supercharge your Docker operations as you move beyond the basics.

Conclusion

In this comprehensive guide, we’ve journeyed through the world of Docker, exploring the ‘docker images ls’ command and delving into the intricacies of advanced Docker image management. We’ve unveiled how the ‘docker images ls’ command, while seemingly simple, is an indispensable tool for listing and managing Docker images, offering a clear overview of your Docker environment.

Finally, we’ve peeked into the Docker Registry API, a powerful tool that provides a programmable interface for managing Docker images and registries. The Docker Registry API allows for automation and integration, propelling Docker operations to new heights.

Whether you’re a Docker novice or a seasoned user, understanding the ‘docker images ls’ command, the principles of Docker image management, and the Docker Registry API are vital for a seamless and efficient Docker experience. So keep exploring, keep learning, and leverage the full potential of what Docker has to offer!