After VNET implemenatation my function runtime became unreachable

Question

After VNET implemenatation my function runtime became unreachable

Neelam Mourya 60 Microsoft Employee

After enabling VNET to my function apps, some of the function apps started giving error message at their overview page and the function became unreachable. function error

navba-MSFT 27,550 Reputation points Microsoft Employee Moderator

2023-07-10T05:52:28.9966667+00:00

@Neelam Mourya Just following up to check if the below answer helped. If that answers your query, do click "Accept the answer” for the same, which might be beneficial to other community members reading this thread. And, if you have any further query do let us know. I would be happy to help.
Neelam Mourya 60 Reputation points Microsoft Employee

2023-07-17T13:14:39.1233333+00:00

Hello @navba-MSFT
Thank you so much for your help.
After adding those property, the function runtime issues is resolved, But now i am not able to do any deployments on it. I get below 403 error while code deploy.

deployment error.png

I am using command to deploy through azure CLI:
az functionapp deployment source config-zip -g $resourceGroupName -n $appName --src $publishZip

Any idea around this issue. This is coming once i have enabled the VNET for my function.
I have already enabled VNET on function's related storage account as well. Both resources are in same subscription and in same region.

1 answer

Your answer

navba-MSFT 27,550 Reputation points Microsoft Employee Moderator

2023-07-10T05:52:28.9966667+00:00

@Neelam Mourya Just following up to check if the below answer helped. If that answers your query, do click "Accept the answer” for the same, which might be beneficial to other community members reading this thread. And, if you have any further query do let us know. I would be happy to help.
Neelam Mourya 60 Reputation points Microsoft Employee

2023-07-17T13:14:39.1233333+00:00

Hello @navba-MSFT
Thank you so much for your help.
After adding those property, the function runtime issues is resolved, But now i am not able to do any deployments on it. I get below 403 error while code deploy.

deployment error.png

I am using command to deploy through azure CLI:
az functionapp deployment source config-zip -g $resourceGroupName -n $appName --src $publishZip

Any idea around this issue. This is coming once i have enabled the VNET for my function.
I have already enabled VNET on function's related storage account as well. Both resources are in same subscription and in same region.

Answer 1

navba-MSFT 27,550 Microsoft Employee Moderator

@Neelam Mourya Welcome to Microsoft Q&A Forum, Thank you for posting your query here!

I understand that you are getting the error Error: Azure Functions Runtime is unreachable after configuring VNET for your FunctionApp.

This issue occurs when the Functions runtime can't start. The most common reason for this is that the function app has lost access to its storage account.

Action Plan:

Please ensure that the Storage account requirements are met.
Also confirm if your Function App VNET is also added in the Azure Storage Account --> Networking section as shown below:
If you are using a new storage account, Secure the new storage account in one of the following ways:

Create a private endpoint. When using private endpoint connections, the storage account must have private endpoints for the file and blob subresources. For Durable Functions, you must also make queue and table subresources accessible through private endpoints.

Enable a service endpoint from the virtual network. When using service endpoints, enable the subnet dedicated to your function apps for storage accounts on the firewall.

3.Update the Application Settings under Configuration for the function app to the following:

User's image

You can set the vnetrouteallenabled property to true. This indicates whether all outbound traffic from the app is routed through the virtual network. The below CLI command helps to set this:

az resource update --resource-group <group-name> --name <app-name> --resource-type "Microsoft.Web/sites" --set properties.vnetRouteAllEnabled true

Please follow the steps mentioned here, which talks about troubleshooting the runtime unreachable issue.

Sharing a few useful articles if that helps:
https://learn.microsoft.com/en-us/azure/azure-functions/configure-networking-how-to?tabs=portal#restrict-your-storage-account-to-a-virtual-network

https://learn.microsoft.com/en-us/azure/azure-functions/run-functions-from-deployment-package#using-website_run_from_package--1

Please let me know if you are still face the issue after following this.

Neelam Mourya 60 Reputation points Microsoft Employee

2023-07-17T13:10:34.77+00:00

Hello @navba-MSFT
Thank you so much for your help.
After adding those property, the function runtime issues is resolved, But now i am not able to do any deployments on it. I get below 403 error while code deploy.

deployment error.png

I am using command to deploy through azure CLI:
az functionapp deployment source config-zip -g $resourceGroupName -n $appName --src $publishZip

Any idea around this issue. This is coming once i have enabled the VNET for my function.
I have already enabled VNET on function's related storage account as well. Both resources are in same subscription and in same region.
navba-MSFT 27,550 Reputation points Microsoft Employee Moderator

2023-07-17T13:57:21.41+00:00
@Neelam Mourya Thanks for getting back. I am glad that the Error: Azure Functions Runtime is unreachable issue is resolved. To address the 403 error follow the below action plan.

Please check if you have Enabled (ON) the access restrictions:

Ensure that the VNet integration is configured correctly for your function app. You can refer to the Azure documentation for detailed instructions on how to configure VNet integration for your function app.

3.If you are using a service endpoint to connect to resources in the VNet, ensure that the service endpoint is configured correctly and has access to the resources in the VNet. You can refer to the Azure documentation for detailed instructions on how to configure a service endpoint.

4.Follow this troubleshooting Guide for VNET Integration troubleshooting.
5. On a side note, if you want to access resources in your VNet from your client machine, you will need to configure a VPN or ExpressRoute connection between your client machine and your VNet. This will allow your client machine to access resources in your VNet as if it were connected to the VNet directly. Alternatively, you can also configure a point-to-site VPN connection between your client machine and your VNet. This will allow your client machine to access resources in your VNet over a secure VPN connection.
Citron, Yonah SITI-PTIY/FH 0 Reputation points

2024-01-24T14:30:29.44+00:00

Hi @Neelam Mourya , I hope you're well. I am facing the same 403 error when trying to re-deploy the content download function. Could you advise what specific steps helped you resolve this issue? Best, Yonah
Neelam Mourya 60 Reputation points Microsoft Employee

2024-01-25T06:19:26.78+00:00

Hi @Citron, Yonah SITI-PTIY/FH
you can enable public access in inbound section temporarily in the function, then perform the deployment activity.
Post deployment, you should revert you changes(uncheck the public access option).
If needed restart you function.

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After VNET implemenatation my function runtime became unreachable

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