Why would my Function disappear from the Portal App?

Question

After editing my function.json file, my function seems to have disappeared from the Function App in Azure Portal.

What happened to my function? Is it gone?

Answer 1

Hello @Michelle Blum ,

For your function to appear in the blade on Azure Portal pictured above, Azure needs to be able to load your function.json file.
We need to verify if the update that was made within the function.json file was properly added. If not, then the file will not be able to index and result in a runtime failure.

As an example, if you added a new setting to the function.json file but did not include all the parameters required to execute the setting, this would lead to the function vanishing from Portal.

The function is not gone. If we navigate to the Kudu for your site (<function-app-name>.scm.azurewebsites.net) -> Debug Console -> CMD -> site -> wwwroot, here we can edit the function.json file.

If the function.json file is able to be loaded again post editing then the function will again appear within the Portal as expected.

Answer 2

Some info: we noticed something like this recently.

Symptoms:

• Functions look to have disappeared
• Function App FQDN not reachable (http 502)
• Kudu working, but no files in root
• Could not redeploy from VS Code (generic "error" message)

I started looking at FA variables/config - nothing had changed.

Nothing changed on NSG/subnets/vnets.

I noticed the App file share/storage was not reachable in FA storage account in Portal or in MSFT Storage Explorer or Storage browser in VS Code.

The issue was a change in the network config in FA to change from allowing access from all networks, to disabling.

As the FA did not have private endpoints, we killed off access to our Function App file storage.

Upon re-enabling access all networks, FA became operational.