How to Check and Manage Container Images in GitHub Container Registry (GHCR)

As containerization becomes a core part of modern DevOps workflows, managing Docker images efficiently and securely is essential. GitHub Container Registry (GHCR) provides a reliable platform for storing and distributing container images directly within your GitHub ecosystem.

In this blog post, we’ll walk through how to check your container images on GitHub, understand the size limitations, best practices, and important precautions to follow.

Step-by-Step Guide to Check Container Images on GitHub

Step 1: Understand Where Your Image Lives

GitHub provides two primary ways to manage containers:

• GitHub Container Registry (GHCR): A dedicated registry located at ghcr.io.
  
  

• Repository-based Dockerfiles: You might store your Docker build files in your GitHub repository but not push images to a registry.
  
  

To verify a pushed image, you must be using GHCR.

Step 2: Visit the GitHub Packages Interface

To view your pushed container images:

For Personal Accounts:

• Go to: https://github.com/users/<your-username>/packages
  
  

For Organization Accounts:

• Go to: https://github.com/orgs/<your-org>/packages
  
  

Here you can:

• Browse uploaded container images
  
  

• See available tags (e.g., latest, v1.0)
  
  

• View image size
  
  

• Copy the docker pull command
  
  

• Check visibility (private/public)
  
  

Note: If you don’t see the image, ensure it was successfully pushed to GHCR, not Docker Hub or another registry.

Step 3: Pull or Inspect the Image via CLI

To validate and inspect the image locally:

docker pull ghcr.io/exampleuser/example-image:latest

docker images

docker image inspect example-image:latest

Important: Use a GitHub Personal Access Token with read:packages scope to authenticate if the image is private.

echo $CR_PAT | docker login ghcr.io -u exampleuser --password-stdin

Use environment variables or secret managers to manage sensitive tokens securely. Avoid hardcoding them.

GHCR Image Size Limitations and Constraints

Although GitHub doesn’t enforce a strict hard cap on image sizes, there are critical performance and policy considerations.

1. Individual Image Size

• There’s no declared total size limit, but practical limits apply during upload/pull operations.
  
  

2. Layer Size Recommendations

• Each image layer should be kept under 10 GB.
  
  

• Large layers may fail during upload or time out in GitHub Actions.
  
  

3. Storage Limits for Private Images

• Free accounts have a soft quota:
  
  

  • 2 GB total private package storage.
    
    

  • Around 500 MB per image version.
    
    

• Public images do not count against storage limits.
  
  

These limits are subject to change based on GitHub’s pricing plans, so check your billing page for current usage.

Best Practices to Optimize and Manage GHCR Images

1. Use Multi-Stage Builds

Reduce image bloat by separating build tools and dependencies from the final runtime container.

2. Break Down COPY/RUN Steps

Avoid creating large layers by copying or installing too much in a single step.

3. Use Public Images Where Possible

Public container images are not counted against storage limits and are ideal for open-source or internal sharing within organizations.

4. Monitor and Clean Up

Regularly review and delete unused images from GHCR to avoid hitting storage limits or exceeding workflow timeouts.

Benefits and Drawbacks of Using GHCR

Merits

• Integrated with GitHub Actions CI/CD
  
  

• Fine-grained access control
  
  

• Supports public and private image hosting
  
  

• Versioning and metadata visibility
  
  

Demerits

• Size constraints for private images (especially on free plans)
  
  

• No built-in automated cleanup policies
  
  

• Requires authentication setup for private images
  
  

Caution & Final Thoughts

While GHCR offers a seamless container experience within the GitHub ecosystem, administrators should be mindful of storage limitations, image layer sizes, and security practices when managing production-ready containers.

If you're planning to deploy from GHCR in a production environment, consider using GitHub Packages with authenticated access, proper tagging strategy, and limited secrets exposure.

Do it at your own risk. Always test image size, registry access, and deployability in staging environments before moving to production.