Microsoft.Extensions.Logging.Abstractions Microsoft.Extensions.DependencyInjection.Abstractions Microsoft.Extensions.DependencyInjection Microsoft.Extensions.Logging

Easy way of logging without configuring anything:

LogManager.Instance.WriteAsync("INFO", ELogType.INFO, true);
LogManager.Instance.WriteAsync("WARNING", ELogType.WARNING, true);
LogManager.Instance.WriteAsync("ERROR", ELogType.ERROR, true);
LogManager.Instance.WriteAsync("DEBUG", ELogType.DEBUG, true);
LogManager.Instance.WriteAsync("CRITICAL", ELogType.CRITICAL, true);
LogManager.Instance.WriteAsync("TRACE", ELogType.TRACE, true);
LogManager.Instance.WriteAsync("TRAFFIC", ELogType.TRAFFIC, true);
LogManager.Instance.WriteAsync("NONE", ELogType.NONE, true);

**Logging in .NET 4.8 or higher: **

public class Program
    {
        public static void Main(string[] args)
        {
            CreateHostBuilder(args).Build().Run();
        }

        public static IHostBuilder CreateHostBuilder(string[] args)
        {
            // Add services to the container.
            FileLoggerOptions options = new FileLoggerOptions();
            options.MaxRolloverFiles = 20;
            options.FileSizeLimit = 1 * 1024 * 1024 / 4;
            options.UseLocalTime = true;

            var builder = Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                }).ConfigureLogging(x => x.AddEonaCatFileLogger(fileLoggerOptions: options, filenamePrefix: "web"));
            return builder;
        }
    }

Example of advanced logging class:

// Import necessary namespaces.
using EonaCat.Logger;
using EonaCat.Logger.Managers;
using EonaCat.Logger.Syslog;
using EonaCat.Logger.SplunkServer;
using EonaCat.Logger.GrayLog;

namespace EonaCat.Logger.Advanced
{
    // The GrayLogSettings class represents settings for GrayLog servers.
    internal class GrayLogSettings
    {
        // Constructor for GrayLogSettings class.
        public GrayLogSettings(string facility, string source, string version = "1.1")
        {
            Facility = facility;
            Source = source;
            Version = version;
        }

        // Facility represents the facility for GrayLog logs.
        public string Facility { get; }
        // Source represents the source for GrayLog logs.
        public string Source { get; }
        // Version represents the version for GrayLog logs (default is "1.1").
        public string Version { get; }
    }

    // The Logger class provides advanced logging functionality.
    internal class Logger
    {
        private static readonly LogManager _logManager;
        private static ConsoleLogTextWriter _consoleLogTextWriter;

        // Exposes a TextWriter property to allow for logging to the console.
        public static TextWriter ConsoleLog { get; internal set; }

        // Static constructor for the Logger class.
        static Logger()
        {
            // Create and configure a LogManager for logging.
            _logManager = new LogManager(new LoggerSettings());
            _logManager.OnException += _logManager_OnException;
            _logManager.OnLogLevelDisabled += _logManager_OnLogLevelDisabled;
            _logManager.Settings.FileLoggerOptions.FileNamePrefix = "advanced";
            _logManager.Settings.UseLocalTime = true;
            _logManager.Settings.FileLoggerOptions.UseLocalTime = true;
            _logManager.Settings.SysLogServers = new List<SyslogServer>();
            _logManager.Settings.SplunkServers = new List<SplunkServer>();
            _logManager.Settings.GrayLogServers = new List<GrayLogServer>();
            _logManager.StartNewLogAsync();
        }

        // Event handler for LogManager exceptions, writes messages to the console.
        private static void _logManager_OnException(object? sender, ErrorMessage e)
        {
            Console.WriteLine(e.Message);
            if (e.Exception != null)
            {
                Console.WriteLine(e.Exception);
            }
        }

         // Event handler for LogManager loglevel disabled notifications, writes messages to the console.
        private static void _logManager_OnLogLevelDisabled(object? sender, ErrorMessage e)
        {
            Console.WriteLine(e.Message);
            if (e.Exception != null)
            {
                Console.WriteLine(e.Exception);
            }
        }

        // Redirects console output to the log.
        public static void RedirectConsoleToLog()
        {
            // Create the callback function to capture console output and log it.
            static void callback(string line) => Info(line, writeToConsole: false);

            _consoleLogTextWriter = new ConsoleLogTextWriter(callback);
            Console.SetOut(_consoleLogTextWriter);
        }

        // Adds a GrayLog server with the specified hostname and port.
        public static void AddGrayLogServer(string hostname, int port)
        {
            _logManager.Settings.GrayLogServers.Add(new GrayLogServer(hostname, port));
        }

        // Removes a GrayLog server from the configuration.
        public static bool RemoveGrayLogServer(GrayLogServer grayLogServer)
        {
            return _logManager.Settings.GrayLogServers.Remove(grayLogServer);
        }

        // Adds a Splunk server with the specified HEC URL and token.
        public static void AddSplunkServer(string splunkHecUrl, string splunkHecToken, bool disableSSL = false)
        {
            var splunkServer = new SplunkServer(splunkHecUrl, splunkHecToken);
            if (disableSSL)
            {
                splunkServer.DisableSSLValidation();
            }
            _logManager.Settings.SplunkServers.Add(splunkServer);
        }

        // Removes a Splunk server from the configuration.
        public static bool RemoveSplunkServer(SplunkServer splunkServer)
        {
            return _logManager.Settings.SplunkServers.Remove(splunkServer);
        }

        // Adds a Syslog server with the specified IP address and port.
        public static void AddSyslogServer(string ipAddress, int port)
        {
            _logManager.Settings.SysLogServers.Add(new SyslogServer(ipAddress, port));
        }

        // Removes a Syslog server from the configuration.
        public static bool RemoveSyslogServer(SyslogServer syslogServer)
        {
            return _logManager.Settings.SysLogServers.Remove(syslogServer);
        }

        // Logs an informational message.
        public static void Info(string message, bool? writeToConsole = null, string? customSplunkSourceType = null, GrayLogSettings grayLogSettings = null)
        {
            WriteAsync(message, ELogType.INFO, writeToConsole, customSplunkSourceType, grayLogSettings);
        }

        // Internal method to write logs.
        private static void WriteAsync(string message, ELogType logType, bool? writeToConsole = null, string? customSplunkSourceType = null, GrayLogSettings grayLogSettings = null)
        {
            if (grayLogSettings != null)
            {
                // Log the message with specified settings.
                _logManager.WriteAsync(message, logType, writeToConsole, customSplunkSourceType, grayLogSettings.Facility, grayLogSettings.Source, grayLogSettings.Version);
            }
            else
            {
                // Log the message with default settings.
                _logManager.WriteAsync(message, logType, writeToConsole, customSplunkSourceType);
            }
        }

        // Logs a debug message.
        public static void Debug(string message, bool? writeToConsole = null, string? customSplunkSourceType = null, GrayLogSettings grayLogSettings = null)
        {
            WriteAsync(message, ELogType.DEBUG, writeToConsole, customSplunkSourceType, grayLogSettings);
        }

        // Logs an error message along with an exception.
        public static void Error(Exception exception, string message = null, bool isCriticalException = false, bool? writeToConsole = null, string? customSplunkSourceType = null, GrayLogSettings grayLogSettings = null)
        {
            if (grayLogSettings != null)
            {
                // Log the exception and message with specified settings.
                _logManager.WriteAsync(exception, message, criticalException: isCriticalException, writeToConsole: writeToConsole, customSplunkSourceType: customSplunkSourceType, grayLogFacility: grayLogSettings.Facility, grayLogSource: grayLogSettings.Source, grayLogVersion: grayLogSettings.Version);
            }
            else
            {
                // Log the exception and message with default settings.
                _logManager.WriteAsync(exception, message, criticalException: isCriticalException, writeToConsole: writeToConsole, customSplunkSourceType: customSplunkSourceType);
            }
        }

        // Logs an error message.
        public static void Error(string message = null, bool? writeToConsole = null, string? customSplunkSourceType = null, string grayLogFacility = null, string grayLogSource = null, string grayLogVersion = "1.1", bool isCriticalException = false)
        {
            if (isCriticalException)
            {
                // Log a critical error message.
                _logManager.WriteAsync(message, ELogType.CRITICAL, writeToConsole);
            }
            else
            {
                // Log a regular error message.
                _logManager.WriteAsync(message, ELogType.ERROR, writeToConsole);
            }
        }

        // Logs a warning message.
        public static void Warning(string message, bool? writeToConsole = null, string? customSplunkSourceType = null, GrayLogSettings grayLogSettings = null)
        {
            WriteAsync(message, ELogType.WARNING, writeToConsole, customSplunkSourceType, grayLogSettings);
        }

        // Logs a critical message.
        public static void Critical(string message, bool? writeToConsole = null, bool? string? customSplunkSourceType = null, bool? GrayLogSettings grayLogSettings = null)
        {
            WriteAsync(message, ELogType.CRITICAL, writeToConsole, customSplunkSourceType, grayLogSettings);
        }

        // Logs a traffic message.
        public static void Traffic(string message, bool? writeToConsole = null, string? customSplunkSourceType = null, GrayLogSettings grayLogSettings = null)
        {
            WriteAsync(message, ELogType.TRAFFIC, writeToConsole, customSplunkSourceType, grayLogSettings);
        }

        // Logs a trace message.
        public static void Trace(string message, bool? writeToConsole = null, string? customSplunkSourceType = null, GrayLogSettings grayLogSettings = null)
        {
            WriteAsync(message, ELogType.TRACE, writeToConsole, customSplunkSourceType, grayLogSettings);
        }
    }
}

Header tokens:

{date} {time} {ts} {tz} {unix} {ticks}{newline} {sev} {category} {env}{newline} {host} {machine}{newline} {process} {pid} {procstart} {uptime}{newline} {thread} {threadname} {task}{newline} {user}{newline} {app} {appbase} {domain}{newline} {framework} {os} {arch}{newline} {mem} {gc}{newline} {cwd}

Example of custom header:

[Date: 2026-01-30] [Time: 14:22:11.384] [2026-01-30 14:22:11.384] [UTC] [Unix: 1738246931] [Ticks: 638422525313840000]
[Severity: Info] [Category: Startup] [Env: Production]
[Host: api-01] [Machine: API-SERVER-01]
[Process: MyService] [PID: 4216] [ProcStart: 2026-01-30T14:20:03.5123456Z] [Uptime: 128s]
[Thread: 9] [ThreadName: worker-1] [TaskId: 42]
[User: svc-api]
[App: MyService.exe] [AppBase: C:\apps\myservice\] [Domain: 1]
[Runtime: .NET 8.0.1] [OS: Linux 6.6.9] [Arch: X64]
[Memory: 128MB] [GC: 12/4/1]
[CWD: /app]

Add Custom tokens:

Logger.LoggerSettings.HeaderTokens.AddCustomToken("spaceShuttleId", context => $"[Shuttle: {context.SpaceShuttleId}]");

Code for enabling GrayLog in the above advanced logger class:

 // Set grayLog information
 var ipAddress = "192.168.10.50"
 var port = 9000;

Logger.AddGrayLogServer(ipAddress, port);

Code for enabling Splunk in the above advanced logger class:

// Set Splunk information
var splunkHecUrl = "https://192.168.10.51:8088/services/collector";
var splunkHecToken = "cf0c7e68-e14b-48c1-949f-efdf5d388254";

Logger.AddSplunkServer(splunkHecUrl, splunkHecToken, true);

Code for enabling SysLog in the above advanced logger class:

 // Set sysLog information
 var ipAddress = "192.168.10.53";
 var port = 514;

Logger.AddSyslogServer(ipAddress, port);

Logging Test with default LogManager:

Task.Run(() => 
{
    var loggerSettings = new LoggerSettings();
    loggerSettings.UseLocalTime = true;
    loggerSettings.FileLoggerOptions.UseLocalTime = true;
    loggerSettings.MaxLogType = ELogType.TRACE;
    loggerSettings.FileLoggerOptions.FileSizeLimit = 1024 * 1024 * 1;
    loggerSettings.FileLoggerOptions.FileNamePrefix = "AllTypes";
    loggerSettings.FileLoggerOptions.MaxRolloverFiles = 5;
	
	// Create an instance of the logManager with the specified loggerSettings
    var logger = new LogManager(loggerSettings);

    // 10.000.000 lines to go :) 
    for (int i = 0; i < 10000000; i++)
    {
        logger.WriteAsync($"test to file {i} INFO", ELogType.INFO);
        logger.WriteAsync($"test to file {i} CRITICAL", ELogType.CRITICAL);
        logger.WriteAsync($"test to file {i} DEBUG", ELogType.DEBUG);
        logger.WriteAsync($"test to file {i} ERROR", ELogType.ERROR);
        logger.WriteAsync($"test to file {i} TRACE", ELogType.TRACE);
        logger.WriteAsync($"test to file {i} TRAFFIC", ELogType.TRAFFIC);
        logger.WriteAsync($"test to file {i} WARNING", ELogType.WARNING);
        logger.WriteAsync($"test to file {i} NONE", ELogType.NONE);
        Console.WriteLine($"Logged: {i}");
        Task.Delay(1);
    }
});

How to retrieve exceptions thrown by the library (from splunk, syslog and grayLog)

LogManager logManager = new LogManager();
logManager.OnException += LogManager_OnException;

private void LogHelper_OnException(object sender, ErrorMessage e)
{
    if (e.Exception != null)
	{
       Console.WriteLine(e.Exception);
	}
	
	if (e.Message != null)
	{
	    Console.WriteLine("Error message from logger: " + e.Message)
	}
}

Example of Discord Logging:

loggingBuilder.AddEonaCatDiscordLogger(options =>
{
    options.WebhookUrl = "https://discord.com/api/webhooks/your_webhook_here";
});

Example of Slack Logging:

loggingBuilder.AddEonaCatSlackLogger(options =>
{
    options.WebhookUrl = "https://hooks.slack.com/services/your_webhook_here";
});

Example of DatabaseLogging:

Create the table:

CREATE TABLE Logs (
    Id INT IDENTITY(1,1) PRIMARY KEY, -- SERIAL for PostgreSQL, AUTO_INCREMENT for MySQL
    Timestamp DATETIME NOT NULL,
    LogLevel NVARCHAR(50),
    Category NVARCHAR(255),
    Message NVARCHAR(MAX),
    Exception NVARCHAR(MAX),
    CorrelationId NVARCHAR(255)
);

MySQL:

using MySql.Data.MySqlClient;

loggingBuilder.AddEonaCatDatabaseLogger(options =>
{
    options.DbProviderFactory = MySqlClientFactory.Instance;
    options.ConnectionString = "Server=localhost;Database=EonaCatLogs;User=root;Password=yourpassword;";
});

SQL Server:

using Microsoft.Data.SqlClient;

loggingBuilder.AddEonaCatDatabaseLogger(options =>
{
    options.DbProviderFactory = SqlClientFactory.Instance;
    options.ConnectionString = "Server=localhost;Database=EonaCatLogs;User Id=sa;Password=yourpassword;";
});

PostgreSQL:

using Npgsql;

loggingBuilder.AddEonaCatDatabaseLogger(options =>
{
    options.DbProviderFactory = NpgsqlFactory.Instance;
    options.ConnectionString = "Host=localhost;Database=EonaCatLogs;Username=postgres;Password=yourpassword;";
});

Example of batching database logging:

loggingBuilder.AddEonaCatBatchingDatabaseLogger(options =>
{
    options.DbProviderFactory = MySql.Data.MySqlClient.MySqlClientFactory.Instance;
    options.ConnectionString = "Server=localhost;Database=EonaCatLogs;User=root;Password=yourpassword;";
    options.BatchInterval = TimeSpan.FromSeconds(10); // Flush every 10 seconds
});

Example of adding custom context to the log messages:

var jsonLogger = new JsonFileLoggerProvider().CreateLogger("MyCategory") as JsonFileLogger;
jsonLogger?.SetContext("CorrelationId", "abc-123");
jsonLogger?.SetContext("UserId", "john.doe");
jsonLogger?.LogInformation("User logged in");

// Output: // [2025-04-25 17:01:00Z] [Information] MyCategory: User logged in CorrelationId=abc-123 UserId=john.doe