Adds the ability to use NLog

.gitpod.yml

@@ -0,0 +1 @@
+image: gitpod/workspace-dotnet

Source/Dna.Framework/Dna.Framework.csproj

@@ -33,5 +33,6 @@
     <PackageReference Include="Microsoft.Extensions.Logging.Configuration" Version="2.0.0" />
     <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="2.0.0" />
     <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="2.0.0" />
+    <PackageReference Include="NLog" Version="4.7.8" />
   </ItemGroup>
 </Project>

Source/Dna.Framework/Logging/NLog/NLogConfiguration.cs

@@ -0,0 +1,29 @@
+using Microsoft.Extensions.Logging;
+
+namespace Dna
+{
+    /// <summary>
+    /// The configuration for the NLog logger
+    /// </summary>
+    public class NLogConfiguration
+    {
+         #region Public Properties
+
+        /// <summary>
+        /// The level of log that should be processed
+        /// </summary>
+        public LogLevel LogLevel { get; set; } = LogLevel.Trace;
+
+        /// <summary>
+        /// Whether to log the time as part of the message
+        /// </summary>
+        public bool LogTime { get; set; } = true;
+
+        /// <summary>
+        /// Indicates if the log level should be output as part of the log message
+        /// </summary>
+        public bool OutputLogLevel { get; set; } = true;
+
+        #endregion
+    }
+}

Source/Dna.Framework/Logging/NLog/NLogExtensions.cs

@@ -0,0 +1,19 @@
+using Microsoft.Extensions.Logging;
+
+namespace Dna
+{
+    public static class NLogExtensions
+    {
+        public static ILoggingBuilder AddNLog(this ILoggingBuilder builder, string path, NLogConfiguration configuration = null)
+        {
+            if (configuration == null)
+            {
+                configuration = new NLogConfiguration();
+            }
+
+            builder.AddProvider(new NLogProvider(path, configuration));
+
+            return builder;
+        }
+    }
+}

Source/Dna.Framework/Logging/NLog/NLogLogger.cs

@@ -0,0 +1,95 @@
+using Microsoft.Extensions.Logging;
+using System;
+using System.IO;
+
+namespace Dna
+{
+    public class NLogLogger : ILogger
+    {
+        protected NLogConfiguration mConfiguration;
+
+        private NLog.Logger mLogger;
+
+        public NLogLogger(string categoryName, string filePath, NLogConfiguration configuration)
+        {
+            mConfiguration = configuration;
+
+            var config = new NLog.Config.LoggingConfiguration();
+            var logfile = new NLog.Targets.FileTarget("logfile") { FileName = Path.GetFullPath(filePath) };
+            var logconsole = new NLog.Targets.ConsoleTarget("logconsole");
+
+            config.AddRule(NLog.LogLevel.Info, NLog.LogLevel.Fatal, logfile);
+            config.AddRule(NLog.LogLevel.Info, NLog.LogLevel.Fatal, logconsole);
+
+            // Apply config           
+            NLog.LogManager.Configuration = config;
+
+            mLogger = NLog.LogManager.GetLogger(categoryName);
+        }
+        public IDisposable BeginScope<TState>(TState state)
+        {
+            return null;
+        }
+
+        public bool IsEnabled(Microsoft.Extensions.Logging.LogLevel logLevel)
+        {
+            return logLevel >= mConfiguration.LogLevel;
+        }
+
+        public void Log<TState>(Microsoft.Extensions.Logging.LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
+        {
+            // if we should log
+            if (!IsEnabled(logLevel))
+            {
+                // Return
+                return;
+            }
+
+            // Get current time
+            var currentTime = DateTimeOffset.Now.ToString("yyyy-MM-dd hh:mm:ss");
+
+            // Prepend log level
+            var logLevelString = mConfiguration.OutputLogLevel ? $"[{logLevel.ToString().ToUpper()}] " : "";
+
+            // prepend log level
+            var timeLogString = mConfiguration.LogTime ? $"[{currentTime}] " : "";
+
+            // Get the formatted message string
+            var message = formatter(state, exception);
+
+            // Write the message
+            var output = $"{logLevelString}{timeLogString}{message}";
+
+            mLogger.Log(ConvertLogLevel(logLevel), output);
+        }
+
+
+        /// <summary>
+        /// Convert log level to NLog variant.
+        /// </summary>
+        /// <param name="logLevel">level to be converted.</param>
+        /// <returns></returns>
+        private static NLog.LogLevel ConvertLogLevel(Microsoft.Extensions.Logging.LogLevel logLevel)
+        {
+            switch (logLevel)
+            {
+                case Microsoft.Extensions.Logging.LogLevel.Trace:
+                    return NLog.LogLevel.Trace;
+                case Microsoft.Extensions.Logging.LogLevel.Debug:
+                    return NLog.LogLevel.Debug;
+                case Microsoft.Extensions.Logging.LogLevel.Information:
+                    return NLog.LogLevel.Info;
+                case Microsoft.Extensions.Logging.LogLevel.Warning:
+                    return NLog.LogLevel.Warn;
+                case Microsoft.Extensions.Logging.LogLevel.Error:
+                    return NLog.LogLevel.Error;
+                case Microsoft.Extensions.Logging.LogLevel.Critical:
+                    return NLog.LogLevel.Fatal;
+                case Microsoft.Extensions.Logging.LogLevel.None:
+                    return NLog.LogLevel.Off;
+                default:
+                    return NLog.LogLevel.Debug;
+            }
+        }
+    }
+}

Source/Dna.Framework/Logging/NLog/NLogProvider.cs

@@ -0,0 +1,33 @@
+using Microsoft.Extensions.Logging;
+using System.Collections.Concurrent;
+
+namespace Dna
+{
+    public class NLogProvider : ILoggerProvider
+    {
+        protected string mFilePath;
+
+        protected readonly NLogConfiguration mConfiguration;
+
+        protected readonly ConcurrentDictionary<string, NLogLogger> mLoggers = new ConcurrentDictionary<string, NLogLogger>();
+
+        public NLogProvider(string path, NLogConfiguration configuration)
+        {
+            // Set the configuration
+            mConfiguration = configuration;
+
+            // Set the path
+            mFilePath = path;
+        }
+
+        public ILogger CreateLogger(string categoryName)
+        {
+            return mLoggers.GetOrAdd(categoryName, name => new NLogLogger(name, mFilePath, mConfiguration));
+        }
+
+        public void Dispose()
+        {
+            mLoggers.Clear();
+        }
+    }
+}