What is a Container Registry? Everything You Need to Know

Tech careers are growing exponentially as more and more people take on careers in programming and related fields. In the world of software programming, there are several puzzle pieces that work together to ensure that the program is functioning as it should. If you are considering working in software development, we’re breaking down the first things you should know about container registries.


This term is associated with the Docker program, a technology that allows you to consolidate and store your code and its data into an image. This image can then be used to create an example of your application, also known as a container. 

Some popular examples of private Docker registries include:

  • Container registry by JFrog: great for strong artifact management, not just Docker images. 
  • Docker Trusted Registry: provides high availability via replication, image auditing, signing, and security scanning. 
  • Harbor 
  • GitLab Container Registry 

A container registry is a collection of repositories (a source that stores files and information) made specifically for the safekeeping of container images. This is especially important for the application construction process. 

Developers should have access to all the container images needed for an application in order for their work to run as smoothly as possible. By hosting all the images in one stored location — the container registry — allows developers to identify and pull images when needed.

In this article, we’re undergoing a complete overview of what a container registry is and how they fit into the Docker system. By the end of this blog, you’ll have a better idea of when and how you would use a container registry. Let’s get started!

What is the Difference Between Repositories and Registries?

Not sure of the difference between a repository and registry? You’re not the only one. These terms are similar and are therefore easy to confuse when discussing the subject of containers. 

A container repository is used to store related images for setup and deployment. They can be used to manage, pull or push images. 

Container registries, on the other hand, store multiple container repositories of container images. They also have to option of being hosted publicly or privately, unlike container repositories.

Public Container Registries vs. Private Container Registries

Public container registries are generally faster and easier. They are ideal for smaller teams that incorporate standard and open-sourced images from public registries. Public registries are also generally easier to use. One of the downsides of public registries is they can be less secure than private registries.

Public registries are generally less secure because individual container images may contain malicious or outdated code which, if goes unpatched, could lead to a data breach. It is also harder to know who has access to read and/or write an image.

Some examples of public Docker registries include:

  • DockerHub: provides automated builds, organization accounts, and integration with source control solutions.
  • Amazon Elastic Container Registry (ECR): supports only private repositories and does not provide automated image building.
  • Google Container Registry (GCR): supports only private repositories and provides automated image builds via integration with Google Cloud Source Repositories, GitHub, and Bitbucket.
  • Azure Container Registry (ACR): supports only private repositories and does not provide automated image building.
  • CoreOS Quay: offers both (paid) private and (free) public repositories, automatic security scanning and automated image builds 

A private registry is a container registry that is set up by the organization using it. They are hosted or on-premise and are typically used by a larger organization or enterprise that is more set on using a container registry. 

Private registries offer more control and customization to meet the specific needs of the user. Developers who have this control over the registry while they work allows an organization to have more freedom in how they choose to manage it. This is why private registries are seen to be the more secure route when it comes to implementing a container registry. An organization can implement as many security measures as they feel are necessary.

How to Ensure Your Container Registry is Secure

Security should always be your organization’s first priority when implementing a container registry, which is why we suggest taking the private registry route. 

Here are other ways you can ensure the security of your container registries:

  • Role-based access control (RBAC).
  • Scanning for vulnerabilities in images.
  • Digitally signing images to ensure each image is trusted.
  • Using authentication methods.

Overall, it is up to you and your organization to decide which type of container registry suits your needs best. Now that you have a base of information to make your decision on, you’ll be well informed to make the right choice for your business. 

About Carson Derrow

My name is Carson Derrow I'm an entrepreneur, professional blogger, and marketer from Arkansas. I've been writing for startups and small businesses since 2012. I share the latest business news, tools, resources, and marketing tips to help startups and small businesses to grow their business.

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