How to Reference YAML Templates Across Projects in Azure DevOps?

Question

How to Reference YAML Templates Across Projects in Azure DevOps?

Hi all,

I'm trying to implement a shared pipeline strategy in Azure DevOps and would really appreciate some guidance on whether this setup is supported or if there's a workaround others are using.

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What I'm trying to accomplish

I want to reuse YAML pipeline templates that are stored in one Azure DevOps project (DevOps), and reference them in a pipeline defined in a different project (WebSuite) all within the same Azure DevOps organization.

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My setup

• Template location (Project A):
  Repository: DevOps/FrontendApp-Pipeline
  Templates: /templates/build.yml, /templates/test.yml
• Pipeline location (Project B):
  Repository: WebSuite/FrontendApp-Pipelines
  File: azure-pipelines.yml

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What I've tried so far

In the pipeline YAML, I added the external repository using a resources.repositories block:

resources:
  repositories:
    - repository: external
      type: git
      name: DevOps/FrontendApp-Pipeline
      endpoint: FrontendApp-Pipeline-ServiceConnection

Then referenced a template like this:

- template: templates/build.yml@external

I also created a service connection in the WebSuite project:

• Type: Other Git
• Authentication: Basic Authentication using a valid Personal Access Token (PAT) with Code (Read) access
• URL: https://dev.azure.com/[org]/DevOps/_git/FrontendApp-Pipeline

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The problem

Even with a successful service connection, the pipeline fails to start, resulting in an "informational run" with this error:

"There was a YAML error preventing Azure Pipelines from determining if the pipeline should run."

I've tried reducing the pipeline to just this for debugging:

steps:
  - checkout: external
  - script: ls -R $(Build.SourcesDirectory)

But the same error persists.

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My questions

1. Is referencing a YAML template from a repository in a different Azure DevOps project supported?
2. If yes, what is the correct way to do it?
3. If not, are there any best practices for reusing templates across projects --- like GitHub mirrors, submodules, or another pattern?

Any insight would be greatly appreciated --- I'd love to avoid duplicating templates across projects if there's a supported solution.

Thanks in advance, Arafat

Answer 1

Hello Arafat Mohammed,

Thank you for posting your question in the Microsoft Q&A forum. 

Yes, referencing YAML templates across Azure DevOps projects is fully supported. Your approach is fundamentally correct but needs these adjustments: 

Service Connection Configuration: 

• Use "Azure Repos/Team Foundation Server" type (not "Other Git") 
• The endpoint URL should be just *https://dev.azure.com/[org]* 
• PAT needs Build (Read) permission, not just Code (Read) 

Repository Resource Syntax (yaml):

 

resources:
   
      - repository: templates
          type: git
          name: DevOps/FrontendApp-Pipeline
          ref: main  # explicit branch reference

The challenge of reusing YAML pipeline templates across different Azure DevOps projects within the same organization represents a common architectural need for many development teams. While Azure DevOps does support this functionality, proper implementation requires careful attention to several configuration details that differ from standard intra-project template references. 

The fundamental architecture involves declaring the external repository as a resource in your pipeline configuration. This approach leverages Azure DevOps' built-in capabilities for cross-project collaboration, but success depends on three critical elements: the correct service connection type, appropriate permissions, and precise reference syntax. The service connection must be configured as "Azure Repos/Team Foundation Server" rather than the more generic "Other Git" option, with authentication handled through a Personal Access Token that includes Build (Read) permissions rather than just basic Code access. 

Alternative Approaches: 

• Extension Method: Package templates as a custom extension 
• GitHub Mirror: Push templates to a GitHub repo (simpler auth model) 
• Pipeline Artifacts: Publish templates as build artifacts and download them 

 

If the above answer helped, please do not forget to "Accept Answer" as this may help other community members to refer the info if facing a similar issue. Your contribution to the Microsoft Q&A community is highly appreciated. 

Answer 2

Hi @Arafat Mohammed ,

If you're trying to reuse YAML templates across different Azure DevOps projects, yes, it’s possible, but you need to set it up properly.

Instead of using a "Generic Git" (Other Git) connection, you need to create a Service Connection of type Azure Repos / Git.

Use the correct Service Connection

• Create a Service Connection of type Azure Repos / Git (not "Other Git").
• Go to Project Settings → Service Connections → New Service Connection → Azure Repos / Git.
• Use a PAT (Personal Access Token) with Code Read permissions.
• Approve the Service Connection for use in pipelines.

Refer this MS Document - GitHub service connection

Reference the external repository in your pipeline:

resources:
  repositories:
    - repository: external
      type: git
      name: DevOps/FrontendApp-Pipeline   
      endpoint: FrontendApp-Pipeline-ServiceConnection

Use the template from the external repo:

stages:
- template: templates/build.yml@external

Important checks

• Service Connection has access to the repository.
• Repository permissions allow read access.
• No need for checkout: external unless you want to work with the files directly.

Hope it helps!

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If you have any other questions or still running into more issues, let me know in the "comments" and I would be happy to help you.