Azure DevOps unable to deploy to Azure Web App

Managed to find the solution to the problem I encountered. ​ ​It was related to the access rights of the guest account on the Azure subscription.

​First of all "Managed Service Identity" was not related to this issue.

These are the steps that were followed to connect the Azure DevOps of Company A to the Azure of Company B:

  • ​Created Web App in Company B Azure
  • ​Azure DevOp's account from Company A, was added as a "Guest User" in the Azure of Company B
  • The DevOp's account is given Contributor rights on both the Azure Subscription, and the Web app.
  • ​In Company A's DevOps, add a "Azure Resource Manager". Choose the settings of Company B's Azure as "Service Principal Authentication"
  • Upon saving Azure Resource Manager, you will be prompted to login. You will need to login with the admin account of Company B's Azure.

I had this problem, and it was an MSI issue but not resolved by creating a VM as is suggested elsewhere on the internet. In my case, I had reset the MSI ID of the app service, which broke the service connection in DevOps (though DevOps didn't tell me this -_-).

It was resolved by removing and re-adding the service connection in DevOps, and re-selecting it in the release pipeline settings.