Azure Functions EF Core Simple Logging ILogger

Question

In an Azure Function I would like to log EF Core Events to the ILogger Injected on the constructor when the Function is invoked. That way I can see the events in the log for the invocation of the Azure Function.

I am using DbContextOptionsBuilder's LogTo (Simple Logging) for example below:

Instead of writing to the Console. I want to write to the ILogger passed to the function via Injection. A different logger is injected for each invocation of the functions. I am trying to figure out how to do that? Since the LogTo is setup once from Startup.cs in Configure method.

     builder.Services.AddDbContext<BfmGamesDbContext>(
         optionsBuilder => {
             optionsBuilder.LogTo(
                 (eventId, level) => true, //!! eventId.Id == CoreEventId.ExecutionStrategyRetrying,
                 (eventData) => {
                     Console.WriteLine($"Event EventIdCode: {eventData.EventIdCode} LogLevel: {eventData.LogLevel} EventId: {eventData.EventId}");
                     if (eventData is ExecutionStrategyEventData retryEventData) {
                         var exceptions = retryEventData.ExceptionsEncountered;
                         var exceptionsLast = exceptions[exceptions.Count - 1];
                         var sb = new StringBuilder();
                         sb.Append($"Retry #{exceptions.Count} with delay {retryEventData.Delay} due to error: HResult:{exceptionsLast.HResult} Message: {exceptionsLast.Message}");
                         if (exceptionsLast is SqlException sqlException) {
                             sb.Append($" SQL Error Number:{sqlException.Number} SQL Server State: {sqlException.State}");
                         }
                         Console.WriteLine(sb.ToString());
                     }
                 });
             optionsBuilder.UseLoggerFactory(LogUtil.ConsoleLoggerFactory);
         }

I am trying to figure out how to replace Console.WriteLine(sb.ToString()); with an ILogger method. I have copy and pasted code to try to get to example.

Basically, I want to log events to ILogger.

I tried to find a way to redirect the Console (no luck). Tried to find a way to figure out what function is calling and use its ILogger (no luck).

Answer 1

I just tried a quick sample.

Can you try the following and let me know how it goes please.

 public override void Configure(IFunctionsHostBuilder builder)
 {
     builder.Services.AddDbContext<MyDbContext>(options =>
         options
             .UseSqlServer("<ConnectionString>"));
    
 }

In your DbContext,

 public class MyDbContext : DbContext
 {
     private readonly ILogger<MyDbContext> _logger;
    
     public MyDbContext(DbContextOptions options, ILogger<MyDbContext> logger) : base(options)
     {
         _logger = logger;
     }
    
     protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
     {
         optionsBuilder
             .LogTo(action =>
             {
                 _logger.LogInformation(action);
                // TODO: Use your implementation
             });
     }
 }

And tried with a simple function.

 public class Function1
 {
     private readonly MyDbContext _myDbContext;
    
     public Function1(MyDbContext myDbContext)
     {
         _myDbContext = myDbContext;
     }
    
     [FunctionName("Function1")]
     public async Task<IActionResult> Run(
         [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
         ILogger log)
     {
         _myDbContext.Database.EnsureCreated();
            
         await _myDbContext.Employees.AddAsync(new Employee() { Name = "John Doe" });
         await _myDbContext.SaveChangesAsync();
    
         return new OkResult();
     }
 }