Log non-output messages to stderr. (#367)

src/Program.cs

@@ -81,6 +81,8 @@ static async Task<int> Main(string[] args)
  _ when ex is TaskCanceledException => string.Empty,
  ODataError _e when ex is ODataError => $"Error {_e.ResponseStatusCode}({_e.Error?.Code}) from API:\n {_e.Error?.Message}",
  ApiException _e when ex is ApiException => $"Error {_e.ResponseStatusCode} from API.",
+ AuthenticationFailedException e => $"Authentication failed: {e.Message}",
+ Identity.Client.MsalException e => $"Authentication failed: {e.Message}",
  _ => ex.Message
  };
 
@@ -124,7 +126,14 @@ static CommandLineBuilder BuildCommandLine()
  builder.AddMiddleware(async (ic, next) =>
  {
  debugEnabled = ic.ParseResult.GetValueForOption<bool>(debugOption);
- listener = AzureEventSourceListener.CreateConsoleLogger(debugEnabled ? EventLevel.LogAlways : EventLevel.Critical);
+ if (debugEnabled)
+ {
+ listener = CreateStdErrLogger(EventLevel.LogAlways);
+ }
+ else
+ {
+ listener = CreateStdErrLogger(EventLevel.Error);
+ }
  await next(ic);
  });
 
@@ -198,6 +207,9 @@ static IHostBuilder CreateHostBuilder(string[] args) =>
  }).ConfigureLogging((ctx, logBuilder) =>
  {
  logBuilder.SetMinimumLevel(LogLevel.Warning);
+ logBuilder.ClearProviders();
+ // Log everything to stderr. Investigate if this breaks scripts that check for stderr instead of the exit code.
+ logBuilder.AddConsole(c => c.LogToStandardErrorThreshold = LogLevel.Trace);
  // Allow runtime selection of log level
  logBuilder.AddFilter("Microsoft.Graph.Cli", level => level >= (debugEnabled ? LogLevel.Debug : LogLevel.Warning));
  });
@@ -214,5 +226,14 @@ static void ConfigureAppConfiguration(IConfigurationBuilder builder, string[] ar
  builder.AddJsonFile(authCache.GetAuthenticationCacheFilePath(), optional: true, reloadOnChange: true);
  builder.AddEnvironmentVariables(prefix: "MGC_");
  }
+
+ static AzureEventSourceListener CreateStdErrLogger(EventLevel level = EventLevel.Informational)
+ {
+ return new AzureEventSourceListener(delegate (EventWrittenEventArgs eventData, string text)
+ {
+ // By default, AzureEventSourceListener.CreateConsoleLogger logs to stdout. Use stderr instead.
+ Console.Error.WriteLine("[{1}] {0}: {2}", eventData.EventSource.Name, eventData.Level, text);
+ }, level);
+ }
  }
 }