CI/CD for .NET framework web jobs

At the moment, there’s a weird in-between. If you want to run a background job that is continuous and/or requires vnet integration, you might have to use a web job. Even more so, if you’re having to run .NET Framework, your best best is to run a v1 web job, not v2, not v3. As the Azure team is pushing heavily adopting .NET Core, the Web Job SDK is moving along with it.

My weird issue

I wanted to move a .NET Framework 4.7 Windows Service to Azure using a Web Job. It had to trigger several little functions on a timer, fairly frequently (as often as every 5 seconds for some). This background job also had interact with IaaS services and therefore connect to a vnet.

So, I solved it by creating a .NET Framework Web Job using File -> New Project -> Web Job. This is assuming you have the Azure Developer Pack installed to Visual Studio. From here, I created a continuous web job and installed the web job extensions that I could use a TimerTrigger.

The pipeline

The hard part was creating the CI/CD pipeline. Turns out that the new, short, sweet .csproj don’t play nice with the older v1 web job tooling.

Going back in time

There’s this old blog post that has a lot of good information on how the older web jobs were configured before. I didn’t have to follow a lot of it, because well, I was using Azure DevOps with the built-in tasks to deploy the web job.

The main takeaways:

For continuous web jobs, enable ‘Always On’ the app service
Ensure you the Microsoft.Web.WebJobs.Publish NuGet package installed on your web job project
Ensure you’re publishing with the right MsBuild properties (see pipeline section below)
There’s an open issue that shed’s some light if you want to make a web job work with the new .csproj as seen by .NET Framework 4.7 and above. If you don't do this, your web deploy package will be empty.

You’re going to need a webjob-publish-settings.json file under the Properties folder of the project.

<PropertyGroup>
    <IsWebJobProject>true</IsWebJobProject>
    <WebJobName>$(AssemblyName)</WebJobName>
    <WebJobType>Continuous</WebJobType>
</PropertyGroup>

The tasks

First, build the solution with the following MSBuild arguments. They should be the same you would use to create a Web Deploy package for traditional Windows-based App Service deployments

- task: VSBuild@1
  displayName: 'Build Solution'
  inputs:
    solution: '**\*.sln'
    msbuildArgs: '/p:DeployOnBuild=true /p:WebPublishMethod=Package /p:PackageAsSingleFile=true /p:SkipInvalidConfigurations=true /p:PackageLocation="$(build.artifactStagingDirectory)/"'
    platform: 'Any CPU'
    configuration: 'Debug'

Then, when you’re wanting to deploy, use the older AzureRmWebAppDeployment@4 task. (Assuming, you published the zip as a build artifact).

- task: AzureRmWebAppDeployment@4
  displayName: 'Deploy Web Job'
  inputs:
    azureSubscription: 'my-subscription-service-connection'
    WebAppName: 'azapp-myapp-dev-001'
    package: '$(Pipeline.Workspace)/**/MyWebJob.zip'