Function App with Vnet integration and Private Endpoint -> Server Response: Service Unavailable

Question

i deployed a function app in our azure tenant. The function app is deployed in a dedicated subnet for private endpoint and in dedicated subnet with vnet integration.

We are trying to deploy from a vm with a devops agent installed(the vm have private endpoint) to test the configuration. If function is not configured with vnet integration and private endpoint, deploy works fine. If function is deployed under vnet integration and private endpoint i'm getting this message:

function is reacheble from internet also is in vnet integration and with provate endpoint(i configured access restriction also for our vpn).

The vm with devops agent is in the same vnet with nsg rule setup correctly.

In function app configuration i configured this parameter:

WEBSITE_DNS_SERVER - 168.63.129.16 WEBSITE_VNET_ROUTE_ALL - 1

as microsoft documentation(i tried without it when function was under vnet and private endpoint but i get same problem)

The command that i run is func azure functionapp publish functionname

Nsg rule are configure as follow:

INBOUND:

source vm subnet - destination function private endpoint subnet -> allow any

I forgot to setup something?

Any advice is really appreciated:)

Answer 1

I suppose you have created a private endpoint for your Azure function in the same subnet that the VM deployed inside. The command func azure functionapp publish functionname required request over the Internet, the problem happened because you have configured access restriction in your Azure function, which blocking this access. You may add the VM subnet in the access restriction.