How to set environment variables in a function app

Question

How to set environment variables in a function app

Parag Kale 25

Hi,

I have a function app deployed to app service. We are not using easy auth in our environment as we use function keys in our environment to secure the http function end points.

I want to know if there is a way for me to set the environment variables like WEBSITE_AUTH_OPENID_ISSUER and WEBSITE_AUTH_CLIENT_ID ?. From what I have read so far, these are automatically set when easy auth is set up. But my requirement is that I somehow need to set it up separately as I am not using easy auth.

Parag Kale 25 Reputation points

2025-05-13T18:34:16.3433333+00:00

I tried using Environment.SetEnvironmentVariable , but I don't think its working.

Basically I am using durable functions monitor https://github.com/microsoft/DurableFunctionsMonitor/tree/main and I am using auth code flow to authenticate the user instead of easy auth.

So the below end point in this tool is looking for these environment variable values , which are not set in my case via easy auth

https://github.com/microsoft/DurableFunctionsMonitor/blob/main/durablefunctionsmonitor.dotnetisolated.core/Functions/EasyAuthConfig.cs#L23
Parag Kale 25 Reputation points

2025-05-13T18:43:23.4866667+00:00

It does not allow me to add directly these environment variables in app service in azure portal. It says "environment variable with this value is not allowed" to be added
Praveen Kumar Gudipudi 1,875 Reputation points Microsoft External Staff Moderator

2025-05-13T19:33:26.7+00:00
Hello Parag Kale,

Thanks for reaching out.
Here’s what you can try:

Azure Portal: You can usually set application settings from the Azure portal by going to your Function App, navigating to the "Configuration" under the "Settings" section, and then adding your custom settings. However, it sounds like you received an error when trying to add them, possibly due to restrictions on what can be set as environment variables.

Azure CLI: If adding through the portal isn't working, try using the Azure CLI. You can add application settings with the following command:

az functionapp config appsettings set --name <FunctionAppName> --resource-group <ResourceGroupName> --settings WEBSITE_AUTH_OPENID_ISSUER=<YourIssuer> WEBSITE_AUTH_CLIENT_ID=<YourClientID>

Be sure to replace <FunctionAppName> and <ResourceGroupName> with the appropriate names, and set your actual values for the issuer and client ID.

Azure PowerShell: If you're more comfortable with PowerShell, you can use the following command:

Set-AzFunctionAppSetting -Name <FunctionAppName> -ResourceGroupName <ResourceGroupName> -AppSetting @{WEBSITE_AUTH_OPENID_ISSUER='<YourIssuer>'; WEBSITE_AUTH_CLIENT_ID='<YourClientID>'}

After setting the environment variables using either CLI or PowerShell, don't forget that any changes to settings require your Function App to be restarted for the new settings to take effect.
Parag Kale 25 Reputation points

2025-05-13T20:22:10.0166667+00:00

I tried with az cli. I get the same message

PS C:\WINDOWS\system32> az functionapp config appsettings set --name <name> --resource-group <rs group> --settings WEBSITE_AUTH_OPENID_ISSUER='https://login.microsoftonline.com/<tenant>' WEBSITE_AUTH_CLIENT_ID='<client_id>'

AppSetting with name 'WEBSITE_AUTH_OPENID_ISSUER' is not allowed.
Praveen Kumar Gudipudi 1,875 Reputation points Microsoft External Staff Moderator

2025-05-13T21:06:49.6933333+00:00

Hello Parag Kale,

We are able to reproduce the issue from our end.

I will take the confirmation from Microsoft internal team and post you the answer accordingly.
Praveen Kumar Gudipudi 1,875 Reputation points Microsoft External Staff Moderator

2025-05-15T20:00:00.0166667+00:00

Hello Parag Kale,

Following up to see if you have chance to check my previous response and please let us know with an update to assist you further on this.
Praveen Kumar Gudipudi 1,875 Reputation points Microsoft External Staff Moderator

2025-05-19T16:57:18.8366667+00:00

Hello Parag Kale,

We haven't heard back from you yet, and I wanted to ensure everything is on track and see if there's anything more, we can assist you with.
Deleted

This comment has been deleted due to a violation of our Code of Conduct. The comment was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.
RithwikBojja 3,055 Reputation points Microsoft External Staff Moderator

2025-05-20T04:30:05.83+00:00

Hello Parag, We haven't heard back from you yet, and I wanted to ensure everything is on track and see if there's anything more, we can assist you with.

1 answer

Your answer

Parag Kale 25 Reputation points

2025-05-13T18:34:16.3433333+00:00

I tried using Environment.SetEnvironmentVariable , but I don't think its working.

Basically I am using durable functions monitor https://github.com/microsoft/DurableFunctionsMonitor/tree/main and I am using auth code flow to authenticate the user instead of easy auth.

So the below end point in this tool is looking for these environment variable values , which are not set in my case via easy auth

https://github.com/microsoft/DurableFunctionsMonitor/blob/main/durablefunctionsmonitor.dotnetisolated.core/Functions/EasyAuthConfig.cs#L23
Parag Kale 25 Reputation points

2025-05-13T18:43:23.4866667+00:00

It does not allow me to add directly these environment variables in app service in azure portal. It says "environment variable with this value is not allowed" to be added
Praveen Kumar Gudipudi 1,875 Reputation points Microsoft External Staff Moderator

2025-05-13T19:33:26.7+00:00

Hello Parag Kale,

Thanks for reaching out.
Here’s what you can try:

Azure Portal: You can usually set application settings from the Azure portal by going to your Function App, navigating to the "Configuration" under the "Settings" section, and then adding your custom settings. However, it sounds like you received an error when trying to add them, possibly due to restrictions on what can be set as environment variables.

Azure CLI: If adding through the portal isn't working, try using the Azure CLI. You can add application settings with the following command:

az functionapp config appsettings set --name <FunctionAppName> --resource-group <ResourceGroupName> --settings WEBSITE_AUTH_OPENID_ISSUER=<YourIssuer> WEBSITE_AUTH_CLIENT_ID=<YourClientID>

Be sure to replace <FunctionAppName> and <ResourceGroupName> with the appropriate names, and set your actual values for the issuer and client ID.

Azure PowerShell: If you're more comfortable with PowerShell, you can use the following command:

Set-AzFunctionAppSetting -Name <FunctionAppName> -ResourceGroupName <ResourceGroupName> -AppSetting @{WEBSITE_AUTH_OPENID_ISSUER='<YourIssuer>'; WEBSITE_AUTH_CLIENT_ID='<YourClientID>'}

After setting the environment variables using either CLI or PowerShell, don't forget that any changes to settings require your Function App to be restarted for the new settings to take effect.
Parag Kale 25 Reputation points

2025-05-13T20:22:10.0166667+00:00

I tried with az cli. I get the same message

PS C:\WINDOWS\system32> az functionapp config appsettings set --name <name> --resource-group <rs group> --settings WEBSITE_AUTH_OPENID_ISSUER='https://login.microsoftonline.com/<tenant>' WEBSITE_AUTH_CLIENT_ID='<client_id>'

AppSetting with name 'WEBSITE_AUTH_OPENID_ISSUER' is not allowed.
Praveen Kumar Gudipudi 1,875 Reputation points Microsoft External Staff Moderator

2025-05-13T21:06:49.6933333+00:00

Hello Parag Kale,

We are able to reproduce the issue from our end.

I will take the confirmation from Microsoft internal team and post you the answer accordingly.
Praveen Kumar Gudipudi 1,875 Reputation points Microsoft External Staff Moderator

2025-05-15T20:00:00.0166667+00:00

Hello Parag Kale,

Following up to see if you have chance to check my previous response and please let us know with an update to assist you further on this.
Praveen Kumar Gudipudi 1,875 Reputation points Microsoft External Staff Moderator

2025-05-19T16:57:18.8366667+00:00

Hello Parag Kale,

We haven't heard back from you yet, and I wanted to ensure everything is on track and see if there's anything more, we can assist you with.
Deleted

This comment has been deleted due to a violation of our Code of Conduct. The comment was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.
RithwikBojja 3,055 Reputation points Microsoft External Staff Moderator

2025-05-20T04:30:05.83+00:00

Hello Parag, We haven't heard back from you yet, and I wanted to ensure everything is on track and see if there's anything more, we can assist you with.

Answer 1

Hello Parag Kale,

You are only supposed to set WEBSITE_AUTH_CLIENT_ID and WEBSITE_AUTH_OPENID_ISSUER settings when deploying DfMon outside Azure (e.g. into a K8s cluster). If you deploy DfMon as an Azure Functions instance, you should not set those settings exactly because they're already set by the platform.

And the recommended authentication mode in that case is server-directed login flow. Instructions on how to configure your AAD application for that flow are here

You can also refer below similar GitHub issue:
https://github.com/microsoft/DurableFunctionsMonitor/issues/104

Please follow above suggested steps and let us know with an update.

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How to set environment variables in a function app

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