Allow configuration of log level severity (#158 closes #149)

src/NLog.Targets.Syslog.Schema/NLog.Targets.Syslog.xsd

@@ -47,6 +47,24 @@
                         <xs:complexType>
                             <xs:choice minOccurs="0" maxOccurs="unbounded">
                                 <xs:element name="facility" type="xs:string" minOccurs="0" maxOccurs="1" />
+                                <xs:element name="perLogLevelSeverity" minOccurs="0" maxOccurs="1">
+                                    <xs:complexType>
+                                        <xs:choice minOccurs="0" maxOccurs="unbounded">
+                                            <xs:element name="fatal" type="xs:string" minOccurs="0" maxOccurs="1" />
+                                            <xs:element name="error" type="xs:string" minOccurs="0" maxOccurs="1" />
+                                            <xs:element name="warn"  type="xs:string" minOccurs="0" maxOccurs="1" />
+                                            <xs:element name="info"  type="xs:string" minOccurs="0" maxOccurs="1" />
+                                            <xs:element name="debug" type="xs:string" minOccurs="0" maxOccurs="1" />
+                                            <xs:element name="trace" type="xs:string" minOccurs="0" maxOccurs="1" />
+                                        </xs:choice>
+                                        <xs:attribute name="fatal" type="xs:string" />
+                                        <xs:attribute name="error" type="xs:string" />
+                                        <xs:attribute name="warn"  type="xs:string" />
+                                        <xs:attribute name="info"  type="xs:string" />
+                                        <xs:attribute name="debug" type="xs:string" />
+                                        <xs:attribute name="trace" type="xs:string" />
+                                    </xs:complexType>
+                                </xs:element>
                                 <xs:element name="rfc" type="xs:string" minOccurs="0" maxOccurs="1" />
                                 <xs:element name="rfc3164" minOccurs="0" maxOccurs="1">
                                     <xs:complexType>

src/NLog.Targets.Syslog/MessageCreation/LogLevelSeverityMapping.cs

@@ -0,0 +1,28 @@
+// Licensed under the BSD license
+// See the LICENSE file in the project root for more information
+
+using System.Collections.Generic;
+using NLog.Targets.Syslog.Settings;
+
+namespace NLog.Targets.Syslog.MessageCreation
+{
+    internal class LogLevelSeverityMapping
+    {
+        private readonly IDictionary<LogLevel, Severity> logLevelSeverityMapping;
+
+        public LogLevelSeverityMapping(LogLevelSeverityConfig logLevelSeverityConfig)
+        {
+            logLevelSeverityMapping = new Dictionary<LogLevel, Severity>
+            {
+                { LogLevel.Fatal, logLevelSeverityConfig.Fatal },
+                { LogLevel.Error, logLevelSeverityConfig.Error },
+                { LogLevel.Warn, logLevelSeverityConfig.Warn },
+                { LogLevel.Info, logLevelSeverityConfig.Info },
+                { LogLevel.Debug, logLevelSeverityConfig.Debug },
+                { LogLevel.Trace, logLevelSeverityConfig.Trace }
+            };
+        }
+
+        public Severity this[LogLevel logLevel] =>  logLevelSeverityMapping[logLevel];
+    }
+}

src/NLog.Targets.Syslog/MessageCreation/MessageBuilder.cs

@@ -16,13 +16,16 @@ internal abstract class MessageBuilder
 
         private readonly SplitOnNewLinePolicy splitOnNewLinePolicy;
         private readonly Facility facility;
+        private readonly LogLevelSeverityMapping logLevelSeverityMapping;
 
         static MessageBuilder()
         {
             BuilderFactory = new Dictionary<RfcNumber, Func<MessageBuilderConfig, EnforcementConfig, MessageBuilder>>
             {
-                { RfcNumber.Rfc3164, (msgBuilderCfg, enforcementCfg) => new Rfc3164(msgBuilderCfg.Facility, msgBuilderCfg.Rfc3164, enforcementCfg) },
-                { RfcNumber.Rfc5424, (msgBuilderCfg, enforcementCfg) => new Rfc5424(msgBuilderCfg.Facility, msgBuilderCfg.Rfc5424, enforcementCfg) }
+                { RfcNumber.Rfc3164, (msgBuilderCfg, enforcementCfg) =>
+                    new Rfc3164(msgBuilderCfg.Facility, msgBuilderCfg.PerLogLevelSeverity, msgBuilderCfg.Rfc3164, enforcementCfg) },
+                { RfcNumber.Rfc5424, (msgBuilderCfg, enforcementCfg) =>
+                    new Rfc5424(msgBuilderCfg.Facility, msgBuilderCfg.PerLogLevelSeverity, msgBuilderCfg.Rfc5424, enforcementCfg) }
             };
         }
 
@@ -31,9 +34,10 @@ public static MessageBuilder FromConfig(MessageBuilderConfig messageBuilderConfi
             return BuilderFactory[messageBuilderConfig.Rfc](messageBuilderConfig, enforcementConfig);
         }
 
-        protected MessageBuilder(Facility facility, EnforcementConfig enforcementConfig)
+        protected MessageBuilder(Facility facility, LogLevelSeverityConfig logLevelSeverityConfig, EnforcementConfig enforcementConfig)
         {
             this.facility = facility;
+            logLevelSeverityMapping = new LogLevelSeverityMapping(logLevelSeverityConfig);
             splitOnNewLinePolicy = new SplitOnNewLinePolicy(enforcementConfig);
         }
 
@@ -46,7 +50,7 @@ public string[] BuildLogEntries(LogEventInfo logEvent, Layout layout)
         public void PrepareMessage(ByteArray buffer, LogEventInfo logEvent, string logEntry)
         {
             buffer.Reset();
-            var pri = Pri(facility, (Severity)logEvent.Level);
+            var pri = Pri(facility, logLevelSeverityMapping[logEvent.Level]);
             PrepareMessage(buffer, logEvent, pri, logEntry);
         }
 

src/NLog.Targets.Syslog/MessageCreation/Rfc3164.cs

@@ -21,7 +21,7 @@ internal class Rfc3164 : MessageBuilder
         private readonly PlainContentPolicySet plainContentPolicySet;
         private readonly AsciiMessagePolicy asciiMessagePolicy;
 
-        public Rfc3164(Facility facility, Rfc3164Config rfc3164Config, EnforcementConfig enforcementConfig) : base(facility, enforcementConfig)
+        public Rfc3164(Facility facility, LogLevelSeverityConfig logLevelSeverityConfig, Rfc3164Config rfc3164Config, EnforcementConfig enforcementConfig) : base(facility, logLevelSeverityConfig, enforcementConfig)
         {
             hostnamePolicySet = new PlainHostnamePolicySet(enforcementConfig);
             tagPolicySet = new TagPolicySet(enforcementConfig);

src/NLog.Targets.Syslog/MessageCreation/Rfc5424.cs

@@ -26,7 +26,7 @@ internal class Rfc5424 : MessageBuilder
         private readonly MsgIdPolicySet msgIdPolicySet;
         private readonly Utf8MessagePolicy utf8MessagePolicy;
 
-        public Rfc5424(Facility facility, Rfc5424Config rfc5424Config, EnforcementConfig enforcementConfig) : base(facility, enforcementConfig)
+        public Rfc5424(Facility facility, LogLevelSeverityConfig logLevelSeverityConfig, Rfc5424Config rfc5424Config, EnforcementConfig enforcementConfig) : base(facility, logLevelSeverityConfig, enforcementConfig)
         {
             version = rfc5424Config.Version;
             hostnameLayout = rfc5424Config.Hostname;

src/NLog.Targets.Syslog/Settings/LogLevelSeverityConfig.cs

@@ -0,0 +1,73 @@
+// Licensed under the BSD license
+// See the LICENSE file in the project root for more information
+
+using System;
+using System.ComponentModel;
+
+namespace NLog.Targets.Syslog.Settings
+{
+    /// <inheritdoc cref="NotifyPropertyChanged" />
+    /// <summary>Log level to severity configuration</summary>
+    public class LogLevelSeverityConfig : NotifyPropertyChanged
+    {
+        private Severity fatal;
+        private Severity error;
+        private Severity warn;
+        private Severity info;
+        private Severity debug;
+        private Severity trace;
+
+        /// <summary>The Syslog severity for log level fatal</summary>
+        public Severity Fatal
+        {
+            get => fatal;
+            set => SetProperty(ref fatal, value);
+        }
+
+        /// <summary>The Syslog severity for log level error</summary>
+        public Severity Error
+        {
+            get => error;
+            set => SetProperty(ref error, value);
+        }
+
+        /// <summary>The Syslog severity for log level warn</summary>
+        public Severity Warn
+        {
+            get => warn;
+            set => SetProperty(ref warn, value);
+        }
+
+        /// <summary>The Syslog severity for log level info</summary>
+        public Severity Info
+        {
+            get => info;
+            set => SetProperty(ref info, value);
+        }
+
+        /// <summary>The Syslog severity for log level debug</summary>
+        public Severity Debug
+        {
+            get => debug;
+            set => SetProperty(ref debug, value);
+        }
+
+        /// <summary>The Syslog severity for log level trace</summary>
+        public Severity Trace
+        {
+            get => trace;
+            set => SetProperty(ref trace, value);
+        }
+
+        /// <summary>Builds a new instance of the LogLevelSeverityConfig class</summary>
+        public LogLevelSeverityConfig()
+        {
+            fatal = Severity.Emergency;
+            error = Severity.Error;
+            warn = Severity.Warning;
+            info = Severity.Informational;
+            debug = Severity.Debug;
+            trace = Severity.Notice;
+        }
+    }
+}

src/NLog.Targets.Syslog/Settings/MessageBuilderConfig.cs

@@ -12,6 +12,8 @@ namespace NLog.Targets.Syslog.Settings
     public class MessageBuilderConfig : NotifyPropertyChanged, IDisposable
     {
         private Facility facility;
+        private LogLevelSeverityConfig perLogLevelSeverity;
+        private readonly PropertyChangedEventHandler perLogLevelSeverityPropsChanged;
         private RfcNumber rfc;
         private Rfc3164Config rfc3164;
         private readonly PropertyChangedEventHandler rfc3164PropsChanged;
@@ -25,6 +27,13 @@ public Facility Facility
             set => SetProperty(ref facility, value);
         }
 
+        /// <summary>Log level Syslog severity related fields</summary>
+        public LogLevelSeverityConfig PerLogLevelSeverity
+        {
+            get => perLogLevelSeverity;
+            set => SetProperty(ref perLogLevelSeverity, value);
+        }
+
         /// <summary>The Syslog protocol RFC to be followed</summary>
         public RfcNumber Rfc
         {
@@ -49,7 +58,11 @@ public Rfc5424Config Rfc5424
         /// <summary>Builds a new instance of the MessageBuilderConfig class</summary>
         public MessageBuilderConfig()
         {
+            perLogLevelSeverity = new LogLevelSeverityConfig();
+            perLogLevelSeverityPropsChanged = (sender, args) => OnPropertyChanged(nameof(PerLogLevelSeverity));
+
             rfc = RfcNumber.Rfc5424;
+
             rfc3164 = new Rfc3164Config();
             rfc3164PropsChanged = (sender, args) => OnPropertyChanged(nameof(Rfc3164));
             rfc3164.PropertyChanged += rfc3164PropsChanged;
@@ -63,6 +76,7 @@ public MessageBuilderConfig()
         /// <summary>Disposes the instance</summary>
         public void Dispose()
         {
+            perLogLevelSeverity.PropertyChanged -= perLogLevelSeverityPropsChanged;
             rfc3164.PropertyChanged -= rfc3164PropsChanged;
             rfc5424.PropertyChanged -= rfc5424PropsChanged;
             rfc5424.Dispose();

src/NLog.Targets.Syslog/Settings/Severity.cs

@@ -0,0 +1,33 @@
+// Licensed under the BSD license
+// See the LICENSE file in the project root for more information
+
+namespace NLog.Targets.Syslog.Settings
+{
+    /// <summary>Syslog severities</summary>
+    public enum Severity
+    {
+        /// <summary>Emergency severity</summary>
+        Emergency = 0,
+
+        /// <summary>Alert severity</summary>
+        Alert = 1,
+
+        /// <summary>Critical severity</summary>
+        Critical = 2,
+
+        /// <summary>Error severity</summary>
+        Error = 3,
+
+        /// <summary>Warning severity</summary>
+        Warning = 4,
+
+        /// <summary>Notice severity</summary>
+        Notice = 5,
+
+        /// <summary>Informational severity</summary>
+        Informational = 6,
+
+        /// <summary>Debug severity</summary>
+        Debug = 7
+    }
+}

src/TestAppWithGUI/NLog.config

@@ -126,6 +126,14 @@
             </sl:enforcement>
             <sl:messageCreation>
                 <sl:facility>Local4</sl:facility>
+                <sl:perLogLevelSeverity>
+                    <sl:fatal>Alert</sl:fatal>
+                    <sl:error>Error</sl:error>
+                    <sl:warn>Warning</sl:warn>
+                    <sl:info>Informational</sl:info>
+                    <sl:debug>Debug</sl:debug>
+                    <sl:trace>Alert</sl:trace>
+                </sl:perLogLevelSeverity>
                 <sl:rfc>Rfc5424</sl:rfc>
                 <sl:rfc3164 hostname="notUsedHostname" tag="notUsedTag" />
                 <sl:rfc5424>

src/TestAppWithTUI/NLog.config

@@ -125,6 +125,14 @@
             </sl:enforcement>
             <sl:messageCreation>
                 <sl:facility>Local4</sl:facility>
+                <sl:perLogLevelSeverity>
+                    <sl:fatal>Critical</sl:fatal>
+                    <sl:error>Error</sl:error>
+                    <sl:warn>Warning</sl:warn>
+                    <sl:info>Informational</sl:info>
+                    <sl:debug>Debug</sl:debug>
+                    <sl:trace>Alert</sl:trace>
+                </sl:perLogLevelSeverity>
                 <sl:rfc>Rfc5424</sl:rfc>
                 <sl:rfc3164 hostname="notUsedHostname" tag="notUsedTag" />
                 <sl:rfc5424>