Can an Azure DevOps Pipeline Access Repositories in a Different Project Collection?

When you try to reference a repository from a different project collection in a YAML pipeline, you run into a limitation of Azure DevOps. While YAML pipelines do support multiple repository resources, they are designed to work with repositories that exist in the same project (or project collection, for that matter). Cross-project references within the same collection can work (with the proper permissions and Git service connections) but extending that to a completely different project collection isn’t supported.

Why Does This Happen?

• Isolation by Design: Azure DevOps isolates project collections. This means that pipelines within one collection don’t have the context or the permission scope to directly reference repositories in another.
• Repository Resources: Even though you can define multiple repository resources in YAML (for example, using the resources.repositories block), these resource definitions expect that the repositories are in the same project or collection.
• Service Connections: Although you might consider setting up a service connection to try and bridge the gap, the YAML pipeline’s native checkout mechanism won’t seamlessly work with repositories from a different collection.

Workarounds

1. Mirror the Repository:
   One approach is to have a mirror of the tools project repository in the target collection. This way, the pipeline can access the mirrored repository without needing to cross the project collection boundary.

2. Build Artifacts:
   Instead of pulling the source code directly from another project collection, consider publishing the tools project as a build artifact in its own pipeline and then consuming that artifact in your pipelines across other collections.

3. Centralize Projects:
   If your organization’s structure permits, consider consolidating related projects into the same project collection. This will enable seamless cross-referencing of repositories.

Example of a Multiple Repository Setup in YAML (Same Collection)

Although the example below is for repositories within the same project collection, it shows how repositories are typically referenced in YAML pipelines:

YAMLCopied
resources:
  repositories:
    - repository: toolsRepo
      type: git
      name: ToolsProject/tools-repository  # This needs to be in the same project/collection
      ref: refs/heads/main

steps:
- checkout: self
- checkout: toolsRepo

Unfortunately, if your tools repository is in a different project collection, the above configuration will not work due to the enforced boundaries.

Conclusion

Currently, YAML pipelines in Azure DevOps do not allow you to directly reference repositories from different project collections. The suggested workarounds involve either consolidating your projects or restructuring your pipeline strategy (using artifacts or mirroring) to work within the supported boundaries.

If further details or updates occur regarding this limitation, reviewing the official Azure DevOps documentation or reaching out to Microsoft support would be the best course of action.