Azure Function App with Deployment Slots Storage Environment

Question

Hi,
I've tried to get an azure function app up and running with deployment slots using bicep templates. The template can create all the resources but I'm having a hard time to get the switch to work, there seem to be some issues with the environment variables.

According to documentation the variable WEBSITE_CONTENTSHARE (https://learn.microsoft.com/en-us/azure/azure-functions/functions-app-settings#website_contentshare) should be omitted when deploying through arm(bicep) templates. It is said to be generated. This is important since it cannot have the same value as the staging slot later. I want to ommitt this environment variable.

I can deploy everything without WEBSITE_CONTENTSHARE and WEBSITE_CONTENTAZUREFILECONNECTIONSTRING (https://learn.microsoft.com/en-us/azure/azure-functions/functions-app-settings#website_contentazurefileconnectionstring), but I get warnings in the portal that storage is not configured correctly.

Checking that page, I see what are required parameters, and I have AzureWebJobsStorage defined.

If I try to add WEBSITE_CONTENTAZUREFILECONNECTIONSTRING, deploy complains that I'm missing required parameter WEBSITE_CONTENTSHARE. But that one I cannot define since it would lead to errors when switching production and staging slots (I've tried). Are there any other environment variables I need to specify? Some older posts and blogs have solved the issue by making the WEBSITE_CONTENTSHARE a deployment slot setting, but that is blocked now. I'm unsure what the problem is here with the function? As a side not, the API works, so as the warning states, I'm worried about scaling.

If I add both the variables WEBSITE_CONTENTAZUREFILECONNECTIONSTRING and WEBSITE_CONTENTSHARE I don't get any warnings, but I cannot use deployment slots. What to do, anyone have any ideas?

Answer 1

Hello @Tore Paulsson - You'll want to define the WEBSITE_CONTENTAZUREFILECONNECTIONSTRING and WEBSITE_CONTENTSHARE settings ONLY at the first time when you are deploying. For all subsequent deployments, you'll want to make sure that the definitions are removed from your template.

Answer 2

Hi, thanks for your reply! I must have missed the e-mail notification!

I have not tried the solution you propose, but after changing the template to not use a separate resource for the app settings (Microsoft.Web/sites/config), everything worked. It seems to be a problem with the validation that occurs for the separate app settings resource. Really odd!

For the app to function properly (if i remember correctly) I had to also clear the existing function app that was deployed since it had a value set for WEBSITE_CONTENTSHARE by my previous deploy.

After these changes everything worked!

Answer 3

Hi @Tore Paulsson , I am facing exactly the same issue when deploying a staging slot using bicep. Do you mind sharing how did you solve this issue? Thanks