How to use template with references to script in another repository within Azure DevOps Pipelines?

Question

I'm trying to use a template that's stored in another Git repository in Azure DevOps where that template has a reference to a script also contained within that repository. While I can successfully use the template from the main pipeline it doesn't reference the script the template requires.

Is there some way I can do this please?

The HelloWorld template/script are stored in Azure DevOps Repo 'HelloWorld' in a sub-folder called 'Templates'.

HelloWorld.ps1 script in the same directory as the below template.

param($Name)

Write-Host "Hello, $Name!"

Template #1 with reference to local script

  parameters:
  - name: azureSubscription
    type: string
  - name: name
    type: string
  
  jobs:
  - job: HelloWorld
    displayName: Hello World
    variables:
      name: ${{ parameters.name }}
    steps:
    - task: AzurePowerShell@4
      name: HelloWorld
      displayName: Hello World
      inputs:
        azureSubscription: ${{ parameters.azureSubscription }}
        scriptType: filePath
        scriptPath: ./HelloWorld.ps1
        azurePowerShellVersion: latestVersion
        failOnStandardError: true
        scriptArguments:
          -Name "$(name)"

Template #2

resources:
  repositories:
    - repository: helloworld
      type: git
      name: HelloWorld

stages:
- stage: Variables
  jobs:
  - template: Scripts/hello-world.yml@helloworld
    parameters:
      azureSubscription: 'My Subscription'
      name: 'Billy'

Answer 1

When you have multiple repositories in your pipeline and you have them when you use template from another repo, they are fetched to their own folders instead of root one. It seems to be obvious but we need to have this in mind.

If you have multiple checkout steps in your job, your source code is checked out into directories named after the repositories as a subfolder of s in (Agent.BuildDirectory). If (Agent.BuildDirectory) is C:\agent_work\1 and your repositories are named tools and code, your code is checked out to C:\agent_work\1\s\tools and C:\agent_work\1\s\code.

Thus when you call a script inside a template which is in another repo you may be forced to provide alias name for the repo to properly locate your script.

For instance:

trigger: none
pr: none

resources:
  repositories:
    - repository: devops
      type: github
      name: kmadof/devops-templates
      endpoint: kmadof

stages:
- template: templates/start.yaml@devops
  parameters:
    repo: devops-templates
    buildSteps:
      - checkout: self
      - checkout: devops
      - bash: echo Test #Passes
        displayName: succeed
      - bash: echo "Test"
        displayName: succeed

I'm passing there repo parameter to use it in my template:

parameters:
- name: repo  # defaults for any parameters that aren't specified
  default: ''

steps:
  - task: PowerShell@2
    inputs:
      filePath: ${{ parameters.repo }}/scripts/myscript.ps1

You can check code here