How can I read the PR tag inside a pipeline triggered by another pipeline? - azure-devops

Question

I had my first question answered here Is it possible to read the PR tag on a pipeline task? but my scenario is a little bit different. I need to read the PR tag from a pipeline that was triggered by another pipeline.
PR triggers the CI which checks if everything's ok for merge. If it is, the CI triggers the CD which will in turn read the PR tag.
PR -> CI -> CD (access the tag here)
I have a PowerShell task named Get PR tag with the following script (courtesy of Lance):
$url = "$($env:SYSTEM_TEAMFOUNDATIONSERVERURI)$env:SYSTEM_TEAMPROJECTID/_apis/git/repositories/$($env:BUILD_REPOSITORY_NAME)/pullRequests/$($env:SYSTEM_PULLREQUEST_PULLREQUESTID)/labels?api-version=5.1-preview.1"
$response = Invoke-RestMethod -Uri $url -Method Get -Headers #{
Authorization = "Bearer $env:SYSTEM_ACCESSTOKEN"
}
Write-Host "##vso[task.setvariable variable=PullRequestTag;isOutput=true]$($response.value.name)"
But I keep getting "The request is invalid.":
========================== Starting Command Output ===========================
/usr/bin/pwsh -NoLogo -NoProfile -NonInteractive -Command . '/home/vsts/work/_temp/74b14931-e33a-4389-b19f-3db7faa53e8d.ps1'
Invoke-RestMethod: /home/vsts/work/_temp/74b14931-e33a-4389-b19f-3db7faa53e8d.ps1:3
Line |
3 | $response = Invoke-RestMethod -Uri $url -Method Get -Headers #{
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| {"count":1,"value":{"Message":"The request is invalid."}}
##[error]PowerShell exited with code '1'.
Finishing: Get PR tag
My agent job is set to use the OAuth token:

Answer 1

Update
In release pipeline, the variable name is not the same as the variable name in build, we need update the url info in the script, we can also check the release pipeline variable in the Initialize job log.
Steps:
a. Configure branch policy and add the policy Build Validation-> add build pipeline A
b. Create release->select the build A as the Source type->Enable the feature Pull request trigger->open Pre-deployment conditions and enable the option Pull request deployment
c. Open the release->enable the feature Allow scripts to access the OAuth token (Click Agent Job Name=>Additional options) add task powershell and enter the script below
$url = "$($env:SYSTEM_TASKDEFINITIONSURI)$env:BUILD_PROJECTID/_apis/git/repositories/$($env:BUILD_REPOSITORY_NAME)/pullRequests/$($env:BUILD_PULLREQUEST_ID)/labels?api-version=5.1-preview.1"
$response = Invoke-RestMethod -Uri $url -Method Get -Headers #{
Authorization = "Bearer $env:SYSTEM_ACCESSTOKEN"
}
Write-Host "##vso[task.setvariable variable=PullRequestTag;isOutput=true]$($response.value.name)"
d. Configure the Reference name as PS and add task cmd to output the tags.
CMD script:
echo $(PS.PullRequestTag)
e. Create pull request and add tags
Result:
Update2
The pull request triggers the CI build pipeline(power shell), after the build pipeline is completed, another build pipeline(power shell test) will be triggered.
b. Open the build pipeline power shell test and add a new variable PullRequestID and grant test Build Service (xxx) account the Edit build pipeline permission. (open the build pipeline(power shell test)--> ... --> Security --> Edit build pipeline set to Allow)
c. enable the feature Allow scripts to access the OAuth token (Click Agent Job Name=>Additional options) add task powershell(Get the tag value) and enter the script below. click the powershell task->Output Variables->enter PS->add a task cmd and use the code echo $(PS.PullRequestTag) to output the tag value
$url = "$($env:SYSTEM_TEAMFOUNDATIONSERVERURI)$env:SYSTEM_TEAMPROJECTID/_apis/git/repositories/$($env:BUILD_REPOSITORY_NAME)/pullRequests/$(PullRequestID)/labels?api-version=5.1-preview.1"
$response = Invoke-RestMethod -Uri $url -Method Get -Headers #{
Authorization = "Bearer $env:SYSTEM_ACCESSTOKEN"
}
Write-Host "##vso[task.setvariable variable=PullRequestTag;isOutput=true]$($response.value.name)"
d. Open build pipeline power shell, enable the feature Allow scripts to access the OAuth token (Click Agent Job Name=>Additional options) add task powershell and enter the script below to update the pipeline(power shell test) variable PullRequestID value.
$url = "$($env:SYSTEM_TEAMFOUNDATIONSERVERURI)$env:SYSTEM_TEAMPROJECTID/_apis/build/definitions/55?api-version=5.1"
Write-Host "URL: $url"
$pipeline = Invoke-RestMethod -Uri $url -Headers #{
Authorization = "Bearer $env:SYSTEM_ACCESSTOKEN"
}
Write-Host "Pipeline = $($pipeline | ConvertTo-Json -Depth 100)"
# Update an existing variable named PullRequestID to its new value pull request ID
$pipeline.variables.PullRequestID.value= $($env:SYSTEM_PULLREQUEST_PULLREQUESTID)
####****************** update the modified object **************************
$json = #($pipeline) | ConvertTo-Json -Depth 99
$updatedef = Invoke-RestMethod -Uri $url -Method Put -Body $json -ContentType "application/json" -Headers #{Authorization = "Bearer $env:SYSTEM_ACCESSTOKEN"}
write-host "=========================================================="
Write-host "The value of Varialbe 'PullRequestID ' is updated to" $updatedef.variables.PullRequestID.value
write-host "=========================================================="