How can I calculate a "build revision" if I don't know the build number until the middle of a job? - azure-devops

Question

I have a build pipeline who's only purpose is to take binaries generated by a legacy build process and package them up into a NuGet package. The version number of the NuGet package needs to match the version number of the binaries, and I'd really like if the run number (YAML "name") also matched, but I also need to tack on a revision number to the end of each build due to the uniqueness rules for NuGet feeds.
I know how to achieve the revision number if I'm using a version number that's known in advance:
versionNumber: 4.0.0
revision: $[counter(variables['versionNumber'], 0)]
buildVersion: $[ format('{0}.{1}', variables.versionNumber, variables.revision) ]
name: $(BuildDefinitionName)_$(versionNumber)-rc$(revision)
but in this case I don't know versionNumber until runtime, because I'm pulling it from the version information on another DLL. So, I have adjusted this to do the following:
- powershell: |
$version = gci -Path $env:BUILD_SOURCESDIRECTORY -Recurse -Filter my.dll | % { $_.versioninfo.ProductVersion }
Write-Host "##vso[task.setvariable variable=version]$version"
- powershell: ${{ format('Write-Host "##vso[task.setvariable variable=revision]{0}"', counter(variables['version'], 0) }}
- powershell: |
$version = "${env:VERSION}-rc${env:REVISION}"
Write-Host "##vso[build.updatebuildnumber]${env:BUILDDEFINITIONNAME}_${version}"
This doesn't work, I assume, because you can't use counter in this context, you can only use it when defining a variable. But if I try to do this earlier in the variables section, the value of the version variable isn't set properly, so I get the wrong counter. Is there any way to get this revision number generated dynamically after I have run the first few tasks to get the version number?

Answer 1

How can I calculate a “build revision” if I don't know the build number until the middle of a job?
It seems you are using the YAML, if yes, I am afraid there is no such way to get the revision number generated dynamically after few tasks to get the version number at this moment.
Just as you test, regardless of whether we put the version number of the task that gets the binary in front of or behind the variable section, we could not seem to get this revision number dynamically generated correctly. It should be the limitation for the YAML at this moment.
As workaround, we could use the classic editor to resolve this issue. Please check following steps:
Create a classic editor pipeline and set the versionNumber with default value in variables tab.
Add powershell scripts to the version number of the binaries.
Invoke REST API (Definitions - Update) to update the default value versionNumber in the variables tab with the new version get from previous powershell task.
Details steps for the latest point:
Go to the Agent Phase and select Allow Scripts to Access OAuth Token. See Use the OAuth token to access the REST API
Grant Project Collection Build Service (xxx) account the edit build pipeline permission. (Select the build pipeline --> ... --> Security --> Edit release definition set to Allow)
Add a PowerShell task in your build pipeline
The poswershell scripts looks like:
$url = "https://dev.azure.com/{organization}/{project}/_apis/build/definitions/{definitionId}?api-version=5.0"
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 TestVar to its new value 2.0.0
$pipeline.variables.versionNumber.value = "<The value you get from previous powershell task>"
####****************** 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 'versionNumber' is updated to" $updatedef.variables.versionNumber.value
Then, we could to see the versionNumber updated to 2.0.0:
Hope this helps.