This Azure function app is down for maintenance
Issue:
· Host is offline?
Solution:
Sometime when you browse your Azure functions you see this message,
This Azure function app is down for maintenance
Mostly this issue happened after deployment.
The reason for this issue is, app_offline.htm file.
You can find this file inside WWWROOT folder of your KUDU site.
When you deploy your function app or app service, Azure create a temporary app_offline.htm file before starting the deployment. This happens to avoid file lock issue.
Once deployment is successful then KUDU automatically delete this file.
Your app appears offline during the deployment.
Sometimes due to some exception or issue app_offile.htm file is not deleted after deployment which ended up with this issue.
To resolve this issue, you can go to KUDU site-> WWWROOT folder and delete this file.
If you'd like to turn this behavior off, please add an SCM_CREATE_APP_OFFLINE App Setting to your app and set the value to 0.