Configure LogLevel of Azure Function using environment variables

Question

As per the Azure documentation, Functions V2 uses the .NET Core logging filter hierarchy for configuration.

In the following example, an instance of ILogger is injected into the Run method of the function.

[FunctionName("MyFunction")]
public static void Run([TimerTrigger("0 */1 * * * *")]TimerInfo myTimer, ILogger logger, ExecutionContext executionContext)
{
    logger.LogInformation("I don't want to see this in production!"));
}

When inspecting the ILogger object, each LoggerInformation element has MinLevel of null which seems to log all levels.

In production, I only want to log at the Error level. I would like to be able to configure this using an environment variable but I cannot find any documentation which explains how to achieve this. I have tried adding the following environment variable to no effect:

"logging__logLevel__Default: "Error" 

Answer 1

Extending the answer given by Pramod

In the portal, navigate to the Azure Function, goto the Configuration blade and press 'New application setting' :

• Name: AzureFunctionsJobHost__logging__logLevel__Default

• Value: Error

NB. Don't forget you need to press OK, then also press Save on the Configuration blade.

Answer 2

Looking at the code (1, 2, 3) for azure functions runtime, this appears to be possible. You have to set it as

export AzureFunctionsJobHost__logging__logLevel__default=Error

This works for other host.json settings too

export AzureFunctionsJobHost__extensions__http__routePrefix=just-another-prefix