Allows Serilog to be configured in a serilog.user.config file that will not effect the main umbraco logger

Adds in support for filtering expressions - so the user logger configuration can filter by including or excluding on an expression - common use case to include only my namespace from SourceContext thjat starts with xyz

src/Umbraco.Core/Logging/Logger.cs

@@ -7,6 +7,7 @@ using Umbraco.Core.Configuration;
 using Umbraco.Core.Diagnostics;
 using Serilog;
 using Serilog.Events;
+using Serilog.Filters;
 using Serilog.Formatting.Compact;
 using Umbraco.Core.Logging.SerilogExtensions;
 
@@ -34,9 +35,9 @@ namespace Umbraco.Core.Logging
             Serilog.Debugging.SelfLog.Enable(msg => System.Diagnostics.Debug.WriteLine(msg));
             
             //Set this environment variable - so that it can be used in external config file
-            //add key="serilog:write-to:RollingFile.pathFormat" value="%BASEDIR%\logs\log-{Date}.txt" />
+            //add key="serilog:write-to:RollingFile.pathFormat" value="%BASEDIR%\logs\log.txt" />
             Environment.SetEnvironmentVariable("BASEDIR", AppDomain.CurrentDomain.BaseDirectory, EnvironmentVariableTarget.Process);
-
+            
             Log.Logger = new LoggerConfiguration()
                 .MinimumLevel.Verbose() //Set to highest level of logging (as any sinks may want to restrict it to Errors only)
                 .Enrich.WithProcessId()
@@ -61,9 +62,12 @@ namespace Umbraco.Core.Logging
                     retainedFileCountLimit: null, //Setting to null means we keep all files - default is 31 days
                     restrictedToMinimumLevel: LogEventLevel.Verbose)
 
-                //A nested logger - where any configured sinks do not effect
+                //Read from main serilog.config file
+                .ReadFrom.AppSettings(filePath: AppDomain.CurrentDomain.BaseDirectory + @"\config\serilog.config")
+
+                //A nested logger - where any user configured sinks via config can not effect the main 'umbraco' logger above
                 .WriteTo.Logger(cfg =>
-                    cfg.ReadFrom.AppSettings(filePath: AppDomain.CurrentDomain.BaseDirectory + @"\config\serilog.config"))
+                    cfg.ReadFrom.AppSettings(filePath: AppDomain.CurrentDomain.BaseDirectory + @"\config\serilog.user.config"))
                 .CreateLogger();
         }
 

src/Umbraco.Core/Umbraco.Core.csproj

@@ -83,6 +83,9 @@
     <PackageReference Include="Serilog.Enrichers.Thread">
       <Version>3.0.0</Version>
     </PackageReference>
+    <PackageReference Include="Serilog.Filters.Expressions">
+      <Version>2.0.0</Version>
+    </PackageReference>
     <PackageReference Include="Serilog.Formatting.Compact">
       <Version>1.0.0</Version>
     </PackageReference>

src/Umbraco.Web.UI/Umbraco.Web.UI.csproj

@@ -279,6 +279,9 @@
       <DependentUpon>HealthChecks.config</DependentUpon>
       <SubType>Designer</SubType>
     </None>
+    <Content Include="Config\serilog.user.config">
+      <SubType>Designer</SubType>
+    </Content>
     <Content Include="Config\serilog.config">
       <SubType>Designer</SubType>
     </Content>

src/Umbraco.Web.UI/config/serilog.config

@@ -1,22 +1,14 @@
 <?xml version="1.0" encoding="utf-8" ?>
 <configuration>
     <appSettings>
-        <!-- Controls log levels for all sinks (Set this higher than child sinks) -->
+
+        <!-- Used to toggle the loge levels for the main Umbraco log files -->
+        <!-- Found at /app_data/logs/ -->
+        <!-- NOTE: Changing this will also flow down into serilog.user.config -->
         <add key="serilog:minimum-level" value="Verbose" />
 
-        <!-- Write to a user log file -->
-        <add key="serilog:using:File" value="Serilog.Sinks.File" />
-        <add key="serilog:write-to:File.path" value="%BASEDIR%\logs\warren-log.txt" /><!-- Can we do a relative path to website ? -->
-        <add key="serilog:write-to:File.restrictedToMinimumLevel" value="Debug" /> 
-        <add key="serilog:write-to:File.retainedFileCountLimit" value="32" /> <!-- Number of log files to keep (or remove value to keep all files) -->
-        <add key="serilog:write-to:File.rollingInterval" value="Day" /> <!-- Create a new log file every Minute/Hour/Day/Month/Year/infinite -->
-
-        <!--
-            TODO
-            * Path relative to the site
-            * Filter logfile to my own namespace only
-            * Have multiple file sink configs (One for main CMS, so it can be fine tuned & another for customer needs if they want to)
-        -->
+        <!-- To write to new log locations (aka Sinks) such as your own .txt files, ELMAH.io, Elastic, SEQ -->
+        <!-- Please use the serilog.user.config file to configure your own logging needs -->
 
     </appSettings>
 </configuration>

src/Umbraco.Web.UI/config/serilog.user.config

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<configuration>
+    <appSettings>
+        
+        <!-- Controls log levels for all user-definied child sub-logger sinks configured here (Set this higher than child sinks) -->
+        <add key="serilog:minimum-level" value="Verbose" />
+
+        <!-- For Different Namespaces - Set different logging levels -->
+        <add key="serilog:minimum-level:override:Microsoft" value="Warning" />
+        <add key="serilog:minimum-level:override:Microsoft.AspNetCore.Mvc" value="Error" />
+        <add key="serilog:minimum-level:override:YourNameSpace" value="Information" />
+
+        <!-- All logs definied via user.config will contain this property (won't be in main Umbraco logs) -->
+        <add key="serilog:enrich:with-property:websiteName" value="Warrens Website" />
+
+        <!-- Write to a user log file -->
+        <add key="serilog:using:File" value="Serilog.Sinks.File" />
+        <add key="serilog:write-to:File.path" value="%BASEDIR%\logs\warren-log.txt" />
+        <add key="serilog:write-to:File.restrictedToMinimumLevel" value="Debug" /> <!-- I will be ignored as Debug as the user logging pipleine has it min set to Information, so only Info will flow through me -->
+        <add key="serilog:write-to:File.retainedFileCountLimit" value="32" /> <!-- Number of log files to keep (or remove value to keep all files) -->
+        <add key="serilog:write-to:File.rollingInterval" value="Day" /> <!-- Create a new log file every Minute/Hour/Day/Month/Year/infinite -->
+
+        <!-- Filters all above sink's to use this expression -->
+        <!-- Common use case is to include SourceType starting with your own namespace -->
+        <add key="serilog:using:FilterExpressions" value="Serilog.Filters.Expressions" />
+        <add key="serilog:filter:ByIncluding.expression" value="StartsWith(SourceContext, 'Umbraco.Core')" />
+
+    </appSettings>
+</configuration>