Logger Bootstrapping

For some Steeltoe components, primarily configuration providers, an ILoggerFactory must be provided to retrieve logs for debugging.

Using BootstrapLoggerFactory

BootstrapLoggerFactory logs to the console until the service container has been built. After the service container has become available, it automatically upgrades existing loggers to use the application configuration and adapt to configuration changes at runtime.

For example, the following code uses BootstrapLoggerFactory to write startup logs from the Config Server configuration provider to the console:

using Steeltoe.Common.Logging;
using Steeltoe.Configuration.ConfigServer;

var builder = WebApplication.CreateBuilder(args);
var loggerFactory = BootstrapLoggerFactory.CreateConsole();

builder.Configuration.AddConfigServer(loggerFactory);
builder.Services.UpgradeBootstrapLoggerFactory(loggerFactory);

All BootstrapLoggerFactory creation methods provide an ILoggingBuilder action parameter that enables further configuration of the startup logger.

For example, the following code adds the Debug logger and sets the minimum level to Warning:

var loggerFactory = BootstrapLoggerFactory.CreateConsole(loggingBuilder =>
{
    loggingBuilder.AddDebug();
    loggingBuilder.SetMinimumLevel(LogLevel.Warning);
});

Tip

To skip usage of the console logger, use BootstrapLoggerFactory.CreateEmpty with the ILoggingBuilder action parameter to configure from scratch.

Using LoggerFactory.Create

An ILoggerFactory can be created directly using LoggerFactory.Create. Beware that this doesn't provide the advantages of BootstrapLoggerFactory.

The following code writes all logs from the Config Server configuration provider to the console:

using Steeltoe.Configuration.ConfigServer;

var builder = WebApplication.CreateBuilder(args);
var loggerFactory = LoggerFactory.Create(loggingBuilder =>
{
    loggingBuilder.AddConsole();
    loggingBuilder.SetMinimumLevel(LogLevel.Trace);
});

builder.Configuration.AddConfigServer(loggerFactory);