How to Secure Azure Container Registry Repositories with ABAC

In modern cloud-native environments, sharing a single Azure Container Registry (ACR) across multiple software teams is a common practice to reduce costs and centralize management. However, this often presents a significant security challenge: how do you ensure that Team A cannot see or pull images belonging to Team B?

Standard Role-Based Access Control (RBAC) often leads to “all-or-nothing” permissions or an unmanageable sprawl of individual role assignments. This is where Attribute-Based Access Control (ABAC) changes the game.

The Problem with Standard RBAC

When using traditional RBAC, granting a team access to a registry typically gives them visibility into every repository within that registry. To restrict access to a specific repository, you would traditionally need to perform role assignments at the repository scope. While this works for two or three repositories, it doesn’t scale for a platform team supporting dozens of departments and hundreds of images.

Managing these individual assignments manually or via automation quickly becomes complex and prone to errors.

Enter Azure ABAC for ACR

Attribute-Based Access Control allows you to define permissions based on specific attributes—in this case, the name of the repository itself. By utilizing the “RBAC with ABAC” mode on your Azure Container Registry, you can create a single role assignment that uses logic to determine access dynamically.

Instead of assigning a role for every repository, you can create one assignment that says: “This identity can read any repository, provided the repository name starts with ‘team-a/’.”

How it Works in Practice

The implementation relies on Azure Role Assignment Conditions. These conditions act as a fine-grained filter on top of the standard “Container Registry Repository Reader” role.

The process involves a few key steps:

1. Enabling ABAC: When creating or updating the ACR, the role assignment mode must be set to support both RBAC and ABAC.
2. Defining the Condition: You write a condition that looks at the request action. If the action is a “read” operation, the condition checks if the repository name matches a specific prefix.
3. Assigning the Role: The role is assigned at the registry scope, but the condition ensures that the user only “sees” the repositories they are authorized for when they list or pull images.

Why This Matters for Platform Engineers

For those managing infrastructure for multiple teams, ABAC provides a scalable, low-maintenance way to enforce least privilege. It simplifies governance by allowing you to use a naming convention (like team-prefixed repository names) to drive security policy.

This approach significantly reduces the number of role assignments you need to track and ensures that as new repositories are created, they are automatically secured based on their name without any additional manual configuration.

Conclusion

Moving toward an attribute-based model is a major step in maturing your cloud security posture. It provides the isolation required for multi-tenant environments while keeping the administrative overhead to a minimum. If you are managing a shared registry, ABAC is the modern standard for balancing accessibility with tight security.

You can find all the code sample on GitHub.

This post was AI-generated based on the transcript of the video “How to Secure Azure Container Registry Repositories with ABAC”.

Video - How to Secure Azure Container Registry Repositories with ABAC