Azure Function Isolated Worker: Is it possible to write the host logs to the console provider?

Question

For a .net 6 isolated worker app these are the logs of an initial run and in here we can see that there are no console provider entries for the 'Executing' and 'Executed' messages, they don't have the 'info:'.

My goal is to have these messages printed like in the image below in which an azure function in-process .net6 app is writing the logs as expected, with the 'info:'.

This is the .net 6 isolated worker code used to print the logs of the first image:

Program.cs

using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

var host = new HostBuilder()
    .ConfigureFunctionsWorkerDefaults()
    .ConfigureServices(services =>
    {
        services.AddApplicationInsightsTelemetryWorkerService();
        services.ConfigureFunctionsApplicationInsights();
    })
    .ConfigureLogging((hostContext, lb) => {
        lb.AddConsole();
    })
    .Build();

host.Run();

local.settings.json

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "FUNCTIONS_WORKER_RUNTIME": "dotnet-isolated"
  }
}

host.json

{
    "version": "2.0",
    "logging": {
        "applicationInsights": {
            "samplingSettings": {
                "isEnabled": true,
                "excludedTypes": "Request"
            },
            "enableLiveMetricsFilters": true
        }
    }
}

.csproj

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
    <OutputType>Exe</OutputType>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.Azure.Functions.Worker" Version="1.20.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Timer" Version="4.1.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="1.16.2" />
    <PackageReference Include="Microsoft.ApplicationInsights.WorkerService" Version="2.21.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.ApplicationInsights" Version="1.0.0" />
    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="8.0.1" />
    <PackageReference Include="Microsoft.Extensions.Logging" Version="8.0.0" />
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
  <ItemGroup>
    <Using Include="System.Threading.ExecutionContext" Alias="ExecutionContext" />
  </ItemGroup>
</Project>

And here we have the .net 6 in-process function code used to print the logs on the second image:

Startup.cs

using Microsoft.Azure.Functions.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;

[assembly: FunctionsStartup(typeof(WorkerLogsToSerilogInProcess.Startup))]
namespace WorkerLogsToSerilogInProcess
{
    internal class Startup : FunctionsStartup
    {
        public override void Configure(IFunctionsHostBuilder builder)
        {
            builder.Services.AddLogging(lb => lb.AddConsole());
        }
    }
}

local.settings.json

{
    "IsEncrypted": false,
    "Values": {
        "AzureWebJobsStorage": "UseDevelopmentStorage=true",
        "FUNCTIONS_WORKER_RUNTIME": "dotnet"
    }
}

host.json

{
    "version": "2.0",
  "logging": {
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": true,
        "excludedTypes": "Request"
      }
    }
  }
}

.csproj

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.Azure.Functions.Extensions" Version="1.1.0" />
    <PackageReference Include="Microsoft.Extensions.Logging" Version="6.0.0" />
    <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="6.0.0" />
    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="4.3.0" />
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
</Project>

In addition to the current code of the isolated function, I've also tried to set the logging:logLevel:default to Information on both the host.json and local.settings.json without success. Reference: Azure function Isolated worker - host vs worker logging config

So, is it possible to write the function runtime logs on the console provider when using an isolated worker azure function?

Answer 1

Can you try modifying Program.cs to be like this:

using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

var host = new HostBuilder()
    .ConfigureFunctionsWorkerDefaults()
    .ConfigureServices(services =>
    {
        services
            .AddApplicationInsightsTelemetryWorkerService()
            .ConfigureFunctionsApplicationInsights()
            .AddLogging(logging =>
            {
                logging.ClearProviders(); // Removes the default console logger
                logging.AddApplicationInsights();
                logging.AddSimpleConsole(c => // Adds a new console logger
                {
                    c.SingleLine = true; // Ensures the "info" etc is at the start of the line.
                });
            });
    })
    .Build();

host.Run();

My thinking is:

• The default console logger is set up for "multi-line" output. This makes it look like it's dropping the info etc. (but in practice, it's just splitting it over multiple lines.)
• By calling .ClearProviders() we're removing that default multi-line logger.
• We then add a single line logger back in.

I don't have an Application Insights resource available at the moment, so I haven't tested whether it still remains enabled after the .ClearProviders(). So do check that still works for you.

Answer 2

I have tried to get the host level logs to the console as you shown with the below process:
Below is the .NET 6 Isolated Azure Function App Project Code:

.csproj code:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
    <OutputType>Exe</OutputType>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>
  <ItemGroup>
    <FrameworkReference Include="Microsoft.AspNetCore.App" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker" Version="1.20.1" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http" Version="3.1.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http.AspNetCore" Version="1.2.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Timer" Version="4.1.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="1.16.4" />
    <PackageReference Include="Microsoft.ApplicationInsights.WorkerService" Version="2.21.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.ApplicationInsights" Version="1.1.0" />
    <PackageReference Include="Microsoft.Extensions.Logging" Version="8.0.0" />
    <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="8.0.0" />
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
  <ItemGroup>
    <Using Include="System.Threading.ExecutionContext" Alias="ExecutionContext" />
  </ItemGroup>
</Project>

Program.cs:

using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

var host = new HostBuilder()
    .ConfigureFunctionsWebApplication()
    .ConfigureServices(services =>
    {
        services.AddLogging(logging =>
        {
            logging.ClearProviders();
            logging.AddConsole();
        });
        services.AddApplicationInsightsTelemetryWorkerService();
        services.ConfigureFunctionsApplicationInsights();
    })
    .Build();

host.Run();

Here I received the console logs including the host-information level as expected but the executing statement is not repeated twice like in your screenshot provided:

For this configuration of host.json:

{
    "version": "2.0",
    "logging": {
      "logLevel": {
        "Function.Function1": "Information",
        "default": "Information"
      },
      "applicationInsights": {
        "samplingSettings": {
          "isEnabled": true,
          "excludedTypes": "Request"
        },

        "enableLiveMetricsFilters": true
      }
    }
}

For this configuration of host.json:

{
    "version": "2.0",
    "logging": {
      "logLevel": {
        "Function.Function1": "Debug",
        "default": "Debug"
      },
      "applicationInsights": {
        "samplingSettings": {
          "isEnabled": true,
          "excludedTypes": "Request"
        },

        "enableLiveMetricsFilters": true
      }
    }
}

Make sure all of my above code files should be same to get the same host level logs to the console.

Reference: MS Doc of Azure functions Host.json