Update 2014-3-3-Hello-World.md

_posts/2014-3-3-Hello-World.md

@@ -1,10 +1,82 @@
 ---
 layout: post
-title: You're up and running!
+title: NLog config in multiple environments deployment
 ---
 
-Next you can update your site name, avatar and other options using the _config.yml file in the root of your repository (shown below).
-
-![_config.yml]({{ site.baseurl }}/images/config.png)
-
-The easiest way to make your first post is to edit this one. Go into /_posts/ and update the Hello World markdown file. For more instructions head over to the [Jekyll Now repository](https://github.com/barryclark/jekyll-now) on GitHub.
+Nlog doesn't support multiple environments config files. But we can reconfig it during run time based on the current asp.net core environment setting.
+- Add settings to asp.net core environment specific congig files(appsettings.Production.json):
+```
+ "Logging": {
+    "NLog": {
+      "LogLevels": {
+        "Default": "Error",
+        "Sql": "Error"
+      }
+    }
+  }
+```
+- Read settings and reconfig in Startup.cs
+```
+       public void UpdateLogLevel()
+        {
+            try
+            {
+                string logLevelSettingPrefix = KeySettingLogPrefix;
+                LogManager.Configuration = LogManager.Configuration.Reload();
+                var logLevels = _configuration.GetSection("Logging:NLog:LogLevels").GetChildren();
+                foreach (var item in logLevels)
+                {
+                    if (!string.IsNullOrWhiteSpace(item.Value))
+                        ChangeLogLevel(item.Key, item.Value);
+                }
+                var settings = Settings;
+                var logLevelSettings = settings.AsQueryable().Where(x => x.Name.Trim().ToLower().StartsWith(KeySettingLogPrefix)).ToList();
+                LogManager.ReconfigExistingLoggers();
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, string.Empty);
+            }
+        }
+        private void ChangeLogLevel(string ruleName, string logLevel)
+        {
+            if (string.IsNullOrWhiteSpace(ruleName))
+            {
+                _logger.LogError("Rule name cannot be empty.");
+                return;
+            }
+            if (string.IsNullOrWhiteSpace(logLevel))
+            {
+                _logger.LogError("Loglevel cannot be empty.");
+                return;
+            }
+            NLog.LogLevel level = null;
+            try
+            {
+                level = NLog.LogLevel.FromString(logLevel);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, $"Invalid Loglevel {logLevel}.");
+                return;
+            }
+            var rules = LogManager.Configuration.LoggingRules;//.Where(x => x.NameMatches(loggerName));
+            foreach (var rule in rules)
+            {
+                if (rule.RuleName?.ToLower() == ruleName.ToLower())
+                {
+                    rule.SetLoggingLevels(level, NLog.LogLevel.Fatal);
+                    //// Iterate over all levels up to and including the target, (re)enabling them.
+                    //for (int i = level.Ordinal; i <= 5; i++)
+                    //{
+                    //    rule.EnableLoggingForLevel(LogLevel.FromOrdinal(i));
+                    //}
+                }
+            }
+        }
+        ...
+        public void ConfigureServices(IServiceCollection services)
+        {
+          UpdateLogLevel();
+        }
+```