Azure pipeline expression does not work in template - azure-devops

Question

I have some templates and i'd like to check if variables are set or not.
So i tried this:
Template that gets included:
- ${{if not(variables.assemblyVersion)}}:
- task: PowerShell#2
inputs:
targetType: 'inline'
script: |
Write-Host $(assemblyVersion)
throw "assemblyVersion was not set"
But even if set assemblyVersion to something (e.g. 1.2.3.4) that task is being ran.
What am i doing wrong?
Edit: tried the answer from Krzysztof Madej, and i got false-positives:
Output:
2020-11-19T09:36:30.7383677Z ##[section]Starting: PowerShell
2020-11-19T09:36:30.7500976Z ==============================================================================
2020-11-19T09:36:30.7501272Z Task : PowerShell
2020-11-19T09:36:30.7501523Z Description : Run a PowerShell script on Linux, macOS, or Windows
2020-11-19T09:36:30.7501778Z Version : 2.170.1
2020-11-19T09:36:30.7501984Z Author : Microsoft Corporation
2020-11-19T09:36:30.7502296Z Help : https://learn.microsoft.com/azure/devops/pipelines/tasks/utility/powershell
2020-11-19T09:36:30.7502761Z ==============================================================================
2020-11-19T09:36:31.9944831Z Generating script.
2020-11-19T09:36:32.1228113Z ========================== Starting Command Output ===========================
2020-11-19T09:36:32.1504771Z ##[command]"C:\windows\System32\WindowsPowerShell\v1.0\powershell.exe" -NoLogo -NoProfile -NonInteractive -ExecutionPolicy Unrestricted -Command ". 'D:\a\_temp\2af656c2-be5b-4a73-8812-17185fff83cc.ps1'"
2020-11-19T09:36:32.4080866Z 1.2.3.4
2020-11-19T09:36:32.7066175Z assemblyVersion was not set
2020-11-19T09:36:32.7066649Z At D:\a\_temp\2af656c2-be5b-4a73-8812-17185fff83cc.ps1:4 char:1
2020-11-19T09:36:32.7067329Z + throw "assemblyVersion was not set"
2020-11-19T09:36:32.7068304Z + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2020-11-19T09:36:32.7069103Z + CategoryInfo : OperationStopped: (assemblyVersion was not set:String) [], RuntimeException
2020-11-19T09:36:32.7069840Z + FullyQualifiedErrorId : assemblyVersion was not set
2020-11-19T09:36:32.7070536Z
2020-11-19T09:36:32.8288504Z ##[error]PowerShell exited with code '1'.
2020-11-19T09:36:32.8929792Z ##[section]Finishing: PowerShell
Main pipeline where yaml is set:
trigger:
- master
- feature/*
pool:
vmImage: 'windows-latest'
variables:
- group: HmiSulis
- name: solution
value: AllProjects.sln
- name: buildPlatform
value: x86
- name: buildConfiguration
value: Debug
- name: assemblyVersion
value: 1.2.3.4
- name: fileVersion
value: 5.6.7.8
- name: informationalVersion
value: 9.10.11.12
resources:
repositories:
- repository: BuildTemplates
type: git
name: HMI/BuildTemplates
extends:
template: netFx/Jobs/netFx.Build.yml#BuildTemplates
The job used:
jobs:
- job: Build
steps:
- template: ../../NuGet/Steps/NuGet.Restore.yml
- template: ../Steps/netFx.Build.Version.yml
- template: ../Steps/netFx.Build.yml
The steps with the checks (netFx.Build.Version.yml):
steps:
- ${{if not(variables['assemblyVersion'])}}:
- task: PowerShell#2
inputs:
targetType: 'inline'
script: |
Write-Host $(assemblyVersion)
throw "assemblyVersion was not set"
- ${{if not(variables['fileVersion'])}}:
- task: PowerShell#2
inputs:
targetType: 'inline'
script: |
throw "fileVersion was not set"
- ${{if not(variables['informationalVersion'])}}:
- task: PowerShell#2
inputs:
targetType: 'inline'
script: |
throw "informationalVersion was not set"
- task: Assembly-Info-NetFramework#2
inputs:
Path: '$(Build.SourcesDirectory)'
FileNames: |
**\AssemblyInfo.cs
**\AssemblyInfo.vb
InsertAttributes: true
FileEncoding: 'auto'
WriteBOM: false
VersionNumber: '$(assemblyVersion)'
# File version in windows explorer
FileVersionNumber: '$(fileVersion)'
# Product version in windows explorer
InformationalVersion: '$(informationalVersion)'
LogLevel: 'verbose'
FailOnWarning: false
DisableTelemetry: false

Answer 1

Please use correct syntax as it is shown here:
variables:
${{ if eq(variables['Build.SourceBranchName'], 'master') }}: # only works if you have a master branch
stageName: prod
pool:
vmImage: 'ubuntu-latest'
steps:
- script: echo ${{variables.stageName}}
so in your case it would be
- ${{if not(variables['assemblyVersion'])}}:
- task: PowerShell#2
inputs:
targetType: 'inline'
script: |
Write-Host $(assemblyVersion)
throw "assemblyVersion was not set"
You can use an if clause to conditionally assign the value or a variable or set inputs for tasks. Conditionals only work when using template syntax.
I simplified your case and it works:
variables:
- name: solution
value: AllProjects.sln
- name: buildPlatform
value: x86
- name: buildConfiguration
value: Debug
- name: assemblyVersion
value: ''
# value: 1.2.3.4
- name: fileVersion
value: 5.6.7.8
- name: informationalVersion
value: 9.10.11.12
pool:
vmImage: 'ubuntu-latest'
jobs:
- job: Build
variables:
- name: test
value: $[not(variables['assemblyVersion'])]
steps:
- ${{if not(variables['assemblyVersion'])}}:
- task: PowerShell#2
continueOnError: true
inputs:
targetType: 'inline'
script: |
Write-Host $(assemblyVersion)
throw "assemblyVersion was not set"
- task: PowerShell#2
continueOnError: true
inputs:
targetType: 'inline'
script: |
Write-Host $(assemblyVersion)
Write-Host $(test)
So when assemblyVersion is given task is skipped. And when is not given task is ran and fail. Be aware $(assemblyVersion) it means that variable have to be available even if not set.
I made further tests moving logic to template. So this is my template:
jobs:
- job: BuildFromTemplate
dependsOn: []
variables:
- name: test
value: $[not(variables['assemblyVersion'])]
steps:
- ${{if not(variables['assemblyVersion'])}}:
- task: PowerShell#2
continueOnError: true
inputs:
targetType: 'inline'
script: |
Write-Host $(assemblyVersion)
throw "assemblyVersion was not set"
- task: PowerShell#2
continueOnError: true
inputs:
targetType: 'inline'
script: |
Write-Host $(assemblyVersion)
Write-Host $(test)
and here is the pipeline:
variables:
- name: assemblyVersion
# value: ''
value: 1.2.3.4
pool:
vmImage: 'ubuntu-latest'
stages:
- stage: A
jobs:
- job: Build
variables:
- name: test
value: $[not(variables['assemblyVersion'])]
steps:
- ${{if not(variables['assemblyVersion'])}}:
- task: PowerShell#2
continueOnError: true
inputs:
targetType: 'inline'
script: |
Write-Host $(assemblyVersion)
throw "assemblyVersion was not set"
- task: PowerShell#2
continueOnError: true
inputs:
targetType: 'inline'
script: |
Write-Host $(assemblyVersion)
Write-Host $(test)
- template: template.yaml
and yes job in template failed:
What seems strange, because:
The difference between runtime and compile time expression syntaxes is primarily what context is available. In a compile-time expression (${{ }}), you have access to parameters and statically defined variables. In a runtime expression ($[ ]), you have access to more variables but no parameters.
and assemblyVersion is statically defined variable.
It looks that we can use only paramaters in template expression in templates and not variables.
I created a bug on developer community for this.
IMHO if you want to use template you need to move this condition into task and just skip logic.
- task: PowerShell#2
continueOnError: true
inputs:
targetType: 'inline'
script: |
$ver = '$(assemblyVersion)'
Write-Host "Ver: $($ver)"
if (!$ver)
{
throw "assemblyVersion was not set"
}
Or use templates variable and reuse it in main file and template file:
parameters:
- name: 'variabaleTemplate'
default: 'variables.yaml'
type: string
jobs:
- job: BuildFromTemplate
dependsOn: []
variables:
- template: ${{parameters.variabaleTemplate}}
- name: test
value: $[not(variables['assemblyVersion'])]
steps:
- ${{if not(variables['assemblyVersion'])}}:
- task: PowerShell#2
continueOnError: true
inputs:
targetType: 'inline'
script: |
Write-Host $(assemblyVersion)
throw "assemblyVersion was not set"
with variables.yaml like
variables:
- name: assemblyVersion
# value: ''
value: 1.2.3.4
and main file like:
stages:
- stage: A
variables:
- template: variables.yaml
jobs:
- template: template2.yaml
So I got reply from MS
For security reasons, we only allow you to pass information into templated code via explicit parameters.
https://learn.microsoft.com/en-us/azure/devops/pipelines/process/templates?view=azure-devops
The means the author of the pipeline using your template needs to commit changes where they explicitly pass the needed info into your template code.
There are some exceptions to this, where the variable is statically defined in the same file or at pipeline compile time, but generally speaking, it’s probably better to use parameters for everything that does not involve system-defined read-only dynamic variable and custom-defined dynamic output variables.
So solution with separate variable template yaml is the best what is possible I think. Otherwise you need to pass all values via template parameters.