Azure function logging not logging in azure application insights with LoggerFactory implementations

Question

I am trying to implement logger without serilog and facing an issue with static class logging with Microsoft Ilogger. I had a similar issue for .net core but I was able to solve it with ASP.NET Core Web API Logging from a Static Class
solution I tried to implement similar in azure function but the message is logging in local console but not in azure application insights

The goal is to log in Static class with Ilogger and LoggerFactory

[assembly: FunctionsStartup(typeof(MicrosoftLoggin.Startup))]
namespace MicrosoftLoggin
{
    public class Startup : FunctionsStartup
    {
        public override void Configure(IFunctionsHostBuilder builder)
        {
            builder.Services.AddLogging(lb =>
            {
                lb.AddFilter("MicrosoftLoggin", LogLevel.Information);               
            });

            builder.Services.AddScoped<ICustomer, Customer>();
            FunctionsHostBuilderContext context = builder.GetContext();

            ApplicationLogging.LoggerFactory = LoggerFactory.Create(builder =>
            {
                builder          
                .AddFilter("MicrosoftLoggin", LogLevel.Information)
                .AddApplicationInsights()
                .AddConsole()
                .SetMinimumLevel(LogLevel.Information)
                .AddConfiguration(context.Configuration);
            });
        }
    }
}

and trying to log like this


public interface ICustomer
    {
        public void TestLogging();
    }

    public class Customer : ICustomer
    {

        private readonly ILogger _logger = ApplicationLogging.CreateLogger(nameof(Customer));

        public Customer(ILogger<Customer> logger)
        {
            Logger = logger;
        }

        private ILogger<Customer> Logger { get; }

        public void TestLogging()
        {
            _logger.LogWarning("With factory logger");
            Logger.LogInformation("With Microsoft Logger");
        }
    }

attached the console log screnshort for reference

I am able to see the "With Microsoft Logger" not the "With factory logger" message.

You need to edit the `host.json` code to log the information also! — , Oct 10 '22 at 14:14

Raffy · Answer 1 · 2022-10-11T20:48:03.003

On your Startup.cs, remove these:

ApplicationLogging.LoggerFactory = LoggerFactory.Create(builder =>
            {
                builder          
                .AddFilter("MicrosoftLoggin", LogLevel.Information)
                .AddApplicationInsights()
                .AddConsole()
                .SetMinimumLevel(LogLevel.Information)
                .AddConfiguration(context.Configuration);
            });

Also just add builder.Services.AddLogging(); without config for its LogLevel is already set to Information by default.

Update your Customer class into the following:

public class Customer : ICustomer
    {

        private readonly ILogger _logger;

        public Customer(ILogger<Customer> logger)
        {
            _logger = logger;
        }

        public void TestLogging()
        {
            _logger.LogWarning("With factory logger");
        }
    }

You don't need the LoggerFactory, the ILogger is injected by the DI container for you. If you're running your function app locally and you want to pass your logging to Application insights, make sure you have the APPINSIGHTS_INSTRUMENTATIONKEY and APPLICATIONINSIGHTS_CONNECTION_STRING values placed in your config file, probably inside your appsettings.json. You can find these values on the Configuration section of your Azure function that's running on Azure.

Logging with DI is working as expected I don't have any issue with that but logging created with LoggerFactory is not logging in APPLICATIONINSIGHTS and the reason why I am trying to use LoggerFactory is to log in static classes also @raffy — Rakesh T.R, Oct 11 '22 at 02:43
@RakeshT.R have you tried my suggested approach on your static classes? Did it work? — Raffy, Oct 11 '22 at 08:05
How can we use ILogger in static class it can be used in class with Constructor Dependency Injection only right @raffy — Rakesh T.R, Oct 11 '22 at 09:50
@RakeshT.R you can try migrating your function from in-process to isolated. The isolated function supports dependency injection for ILogger — Raffy, Dec 15 '22 at 09:26

Azure function logging not logging in azure application insights with LoggerFactory implementations

1 Answers1