Docker in Docker: 'unshare: operation not permitted' when running GitHub Actions Runner on Azure Container Apps" #513

[mamtaRaiTech]

The error message failed to register layer: unshare: operation not permitted indicates that the Docker daemon is attempting to perform an operation restricted by security policies within Azure Container Apps. This issue is commonly associated with the use of the fuse-overlayfs storage driver, which is often employed in rootless Docker configurations.
GITHUB

Recommendations to Resolve the Issue:

Use the overlay2 Storage Driver:

The overlay2 driver is generally more compatible and efficient than fuse-overlayfs. It is recommended to configure Docker to use the overlay2 storage driver instead of fuse-overlayfs.
Adjust Security Settings:

The error may be related to security profiles, such as seccomp or user namespaces, which restrict certain system calls. To test if these security profiles are causing the issue, you can run the Docker container with the --privileged flag, which grants the container additional privileges:
bash
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docker run --privileged your_image
Note: Using the --privileged flag grants the container elevated privileges, which can pose security risks. It is advisable to use this flag only for testing purposes and to identify the root cause of the issue.
STACK OVERFLOW
Review Azure Container Apps Configuration:

Ensure that the Azure Container Apps environment allows the necessary operations for Docker to function correctly. Some operations may be restricted in certain environments for security reasons.
Consult Azure Documentation and Support:

Review Azure's official documentation for any known limitations or configurations related to Docker usage within Azure Container Apps. If the issue persists, consider reaching out to Azure support for assistance.
By implementing these recommendations, you should be able to address the unshare: operation not permitted error and achieve successful image pulls within your Docker-in-Docker setup on Azure Container Apps.

[tianon]

I'm sorry, but I don't think this is a problem with / something we can resolve in the image. I think this is likely related to how you're deploying to Azure Container Apps and/or a limitation in that product itself.