Overview

Availability: .NET 5

Documentation: https://learn.microsoft.com/en-us/dotnet/core/extensions/console-log-formatter

The Console log provider supports three formatting options: Simple, Systemd, and Json.

Registering

To register any one of the formatters, use the Add{TYPE}Console extension method:

using Microsoft.Extensions.Logging;

using ILoggerFactory loggerFactory =
    LoggerFactory.Create(builder =>
        builder.AddSimpleConsole(options =>
        {
            options.IncludeScopes = true;
            options.SingleLine = true;
            options.TimestampFormat = "HH:mm:ss ";
        }));

Registering via Configuration File

{
    "Logging": {
        "LogLevel": {
            "Default": "Information",
            "Microsoft": "Warning",
            "Microsoft.Hosting.Lifetime": "Information"
        },
        "Console": {
            "LogLevel": {
                "Default": "Information",
                "Microsoft": "Warning",
                "Microsoft.Hosting.Lifetime": "Information"
            },
            "FormatterName": "json",
            "FormatterOptions": {
                "SingleLine": true,
                "IncludeScopes": true,
                "TimestampFormat": "HH:mm:ss ",
                "UseUtcTimestamp": true,
                "JsonWriterOptions": {
                    "Indented": true
                }
            }
        }
    },
    "AllowedHosts": "*"
}

Simple

Can wrap information such as time and log level in each log message
Supports ANSI color embedding
Supports indentation fo messages

Systemd

Uses the syslog standard
Always logs messages on a single line
No color support

Json

Writes logs in JSON format
By default, logs messages on a single line
- Use JsonWriterOptions.Indented = true to improve readability
Do not pass in log messages that have already been serialized to JSON

Custom Formatters

To create a custom formatter, inherit from ConsoleFormatter and register the custom formatter.

Documentation: https://learn.microsoft.com/en-us/dotnet/core/extensions/console-log-formatter#implement-a-custom-formatter