Trigger an Azure Webjob from Power Automate

On this post let us see how to trigger or run a WebJob from Power Automate. WebJob is a powerful service in Azure keeping in mind the supported file types or programs it can run. Before proceeding with the instructions to call a WebJob in Power Automate, let us see some basics of an Azure WebJob. WebJobs is a feature of Azure App Service that enables you to run a program or script in the same instance of the Azure web app with no additional cost. As of now it is not supported in App service plan for Linux. There are two types of WebJobs

  1. Continuous WebJob
    • Starts immediately when the WebJob is created. To keep the job from ending, the program or script typically does its work inside an endless loop.
    • Runs on all instances that the web app runs on. You can optionally restrict the WebJob to a single instance.
  2. Triggered WebJob
    • Starts only when triggered manually or on a schedule based on CRON expression.
    • Runs on a single instance that Azure selects for load balancing.

Supported file types for scripts or programs:

The following file types are supported:

  • .cmd, .bat, .exe (using Windows cmd)
  • .ps1 (using PowerShell)
  • .sh (using Bash)
  • .php (using PHP)
  • .py (using Python)
  • .js (using Node.js)
  • .jar (using Java)

Check here the documentation from Microsoft to choose between Flow, Logic Apps, Functions & Webjobs for your automation services with comparisons against each other. If you are using a Function app with a Consumption plan your function can run only to a max of 10 mins. If you can have a long running task on a webjob, set this property in the App service Application setting from the Configuration blade as shown below

The above setting is to avoid idling out if there is no CPU activity. The IDLE timeout setting is set to 1 hour in the above screenshot.

Azure WebJobs SDK:

There is a Powerful Azure WebJobs SDK which simplifies the task of writing background processing code that runs in WebJobs. It makes it easier to write code that reads or writes from Azure Storage account and it also facilitates to trigger the WebJob if there is any new data on the queue, blob, table, service bus for an event driven architecture. Azure functions is built on the WebJobs SDK. If you set your web app to run continuous or scheduled (timer-trigger) WebJobs, enable the Always on setting on your web app’s Azure Configuration page to ensure that the WebJobs run reliably. This feature is available only in the Basic, Standard, and Premium tiers of the App service plan.

Create and Deploy a WebJob:

To call a WebJob from Power Automate, let us create a Triggered WebJob (.Net Framework) from Visual Studio. There is a also support for .NET Core console apps as WebJobs. Refer this documentation from Microsoft to create a WebJob from Visual Studio. In Visual studio there is a template to create a WebJob project as shown below

This is how the VS project looks like

The Program.cs has the code to ensure that the Job will be running continuously, for this case it is not required comment or remove the code which is highlighted. The Functions.cs has the code to pick up the message from the Storage Queue (Event-Driven) through the WebJobs SDK runtime, the WebApp must set to Always on to make it work. For this example, it is not required since it is going to be a triggered Job so the file Functions.cs can be deleted.

If you have any arguments to be passed from Power Automate, you can access it on your code as shown below

To deploy the WebJob, right click the project and select Publish. If there is no publish profile yet, create one or export it from Azure WebApp and then Publish. To know more about the Publish settings In the Publish tab, choose Edit as shown below

The WebJob will be now in Azure. Go to your Azure WebApp or App Service and click WebJobs under the settings blade to find the WebJob deployed from Visual Studio. Find the WebJob in the Azure portal

WebJobs API endpoint for the WebJob:

There are API endpoints available for the Azure WebJob which will be used for triggering the WebJob from Power Automate. Go through the following documentation for more details on the list of available endpoints:

https://github.com/projectkudu/kudu/wiki/WebJobs-API

To Trigger or Start a WebJob, you should have the Webhook URL from the Azure Portal. To get the URL, click Properties after selecting the WebJob as shown below

Copy the Web hook URL, User Name and Password to be later used in Power Automate. Let us trigger the WebJob from Postman client using the above information

Method: Post

URL: https://yourappname.scm.azurewebsites.net/api/triggeredwebjobs/webjobname/run

Authorization Type: Basic Auth

User Name and Password copied from the Portal

This will trigger the Job.

If there are parameters to be passed, the API would be like

https://youwebappname.scm.azurewebsites.net/api/triggeredwebjobs/youwebjobname/run?arguments={arg1} {arg2}

Trigger from Power Automate:

Till now we have the WebJob published in Azure, can we call an API in Power Automate. Yes, it is possible with the help of the Premium action HTTP as shown below

Voila! The WebJob has been triggered from Power Automate.

Summary: On this post we have seen how to call a WebJob using PowerAutomate. There is also a trigger to calla  Flow from a PowerApp, which could be used to start the WebJob. Hope you have found this informational & helpful. Let me know any feedback or comments on the comment section below