Requirements file not installed during Python Function App YAML deployment

Question

I've followed this document here but still running into issues.

I have deployed the function app infrastructure using an ARM template using a YAML IaC pipeline.

I am now trying to deploy the Python code itself. It has a simple utc to current timezone converter function.

The requirements.txt file is as follows:

# DO NOT include azure-functions-worker in this file  
# The Python Worker is managed by Azure Functions platform  
# Manually managing azure-functions-worker may cause unexpected issues  
  
azure-functions  
azure-servicebus  
azure-storage-file-datalake  
python-dateutil  
pytest  

My YAML pipeline is as follows:

trigger:  
  branches:  
    include:  
    - releases/*  
    - refs/tags/func-sbtools*  
  paths:  
    include:  
    - function-app/func-sbtools/*  
  
  
 pool:  
   vmImage: 'ubuntu-latest'  
      
 variables:  
   buildPlatform: 'Any CPU'  
   buildConfiguration: 'Release'  
   pythonVersion: '3.9'  
      
 stages:  
    - stage: publish_artifacts  
      displayName: Publish deployment artifacts  
      jobs:  
      - job: sbtools_drop  
        displayName: Create build artifacts for sbTools deployment  
        steps:  
        - checkout: self   
  
        - task: UsePythonVersion@0  
          inputs:  
            versionSpec: '$(pythonVersion)'  
          displayName: 'Use Python $(pythonVersion)'  
  
        - task: CopyFiles@2  
          displayName: Copy function app files to staging directory  
          inputs:  
            SourceFolder: '$(System.DefaultWorkingDirectory)/function-app/func-sbtools/'  
            Contents: '**'  
            TargetFolder: '$(Build.ArtifactStagingDirectory)'  
        
        - script: |  
              python -m venv antenv  
              source antenv/bin/activate  
              python -m pip install --upgrade pip  
              pip install setup  
              pip install -r requirements.txt  
          workingDirectory: '$(Build.ArtifactStagingDirectory)'  
          displayName: "Install requirements"  
          
  
        - task: ArchiveFiles@2  
          displayName: 'Create sbTools function app drop zip'  
          inputs:  
            rootFolderOrFile: '$(Build.ArtifactStagingDirectory)'  
            includeRootFolder: false  
            archiveType: 'zip'  
            archiveFile: '$(Build.ArtifactStagingDirectory)/sbtools_$(Build.BuildId).zip'  
            replaceExistingArchive: true  
      
        - task: PublishBuildArtifacts@1  
          displayName: Publish sbTools function app drop  
          inputs:  
            PathtoPublish: '$(Build.ArtifactStagingDirectory)/sbtools_$(Build.BuildId).zip'  
            ArtifactName: 'sbtools-drop'  
            publishLocation: 'Container'  
              
    - stage: sit_deploy  
      displayName: SIT deployment  
      dependsOn: [publish_artifacts]  
      jobs:  
      - job: sbtools_sit  
        displayName: Create build artifacts  
        steps:  
        - checkout: self  
        - download: current  
          displayName: Download func-sbtools drop  
          artifact: sbtools-drop  
          
        - task: UsePythonVersion@0  
          inputs:  
            versionSpec: '$(pythonVersion)'  
          displayName: 'Use Python version $(pythonVersion)'  
              
        - task: AzureFunctionApp@1  
          displayName: 'Deploy sbTools code'  
          inputs:  
            azureSubscription: 'Azure DevOps (Dev/Test)'  
            appType: 'functionAppLinux'  
            appName: 'func-sbtools-sit'  
            package: '$(Pipeline.Workspace)/sbtools-drop/sbtools_$(Build.BuildId).zip'  

The pipeline when run completes successfully.

When I test the function in Postman, I get a 500 Internal Server Error response. I've logged the call through App Insights and it says it can't find the 'dateutil' module, which I think is due to the requirements.txt file not being correctly deployed. Here is the exception message from App Insights:

Exception while executing function: Functions.calcUtcToLocaltime <--- Result: Failure Exception: ModuleNotFoundError: No module named 'dateutil'. Troubleshooting Guide: https://aka.ms/functions-modulenotfound Stack: File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/dispatcher.py", line 315, in _handle__function_load_request func = loader.load_function( File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/utils/wrappers.py", line 42, in call raise extend_exception_message(e, message) File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/utils/wrappers.py", line 40, in call return func(*args, **kwargs) File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/loader.py", line 85, in load_function mod = importlib.import_module(fullmodname) File "/usr/local/lib/python3.9/importlib/init.py", line 127, in import_module return _bootstrap._gcd_import(name[level:], package, level) File "/home/site/wwwroot/calcUtcToLocaltime/init.py", line 3, in <module> from dateutil import parser, tz

I noticed in the docs that I might have needed to add the app setting SCM_DO_BUILD_DURING_DEPLOYMENT=true to the function app settings config due to how I deployed the infrastructure. I have done so and this has made no difference.

I've checked the pipeline logs for the build and I can see dateutil being downloaded:

At this point I am stuck and would appreciate where I am not executing the requirements correctly.

Answer 1

Hello,

After a few days looking into all the issues open on this, I've located the fix, the build for v3.7+ should refer to:

pip install --target="./.python_packages/lib/site-packages" -r ./requirements.txt

in the build rather than:

pip install -r requirements.txt

Please update your documentation to include this.

I've also specified deploymentMethod: zipDeploy in the final deployment task.

Thanks