Configuring NLog programmatically

Question

I have a working configure of NLog. I use NLog.config

<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" autoReload="true" internalLogFile="e:\InternalLog.txt" throwExceptions="true">
  <targets>
    <target name="database" xsi:type="Database">
      <connectionStringName>DB.Log</connectionStringName>
      <commandText>
        insert into dbo.Log (
          Logged, Level, Message, Username, Url, Logger, CallSite, Exception, Stacktrace, remoteAddress
        ) values (
          @Logged, @Level, @Message, @Username, @Url, @Logger, @CallSite, @Exception, @Stacktrace, @RemoteAddress
        );
      </commandText>
      <parameter name="@logged" layout="${date}" />
      <parameter name="@level" layout="${level}" />
      <parameter name="@message" layout="${message}" />
      <parameter name="@username" layout="${identity}" />
      <parameter name="@url" layout="${aspnet-request:serverVariable=HTTP_URL}${aspnet-request:queryString}" />
      <parameter name="@remoteAddress" layout="${aspnet-request:serverVariable=REMOTE_ADDR}:${aspnet-request:serverVariable=REMOTE_PORT}" />
      <parameter name="@logger" layout="${logger}" />
      <parameter name="@callSite" layout="${callsite}" />
      <parameter name="@exception" layout="${exception:format=tostring}" />
      <parameter name="@stacktrace" layout="${stacktrace:format=DetailedFlat}" />
    </target>
  </targets>
  <rules>
    <logger name="*" writeTo="database" />
  </rules>
</nlog>

and it works fine. But now i need to configure NLog programmatically. So I try

var config = new LoggingConfiguration();
var dbTarget = new DatabaseTarget {
    ConnectionString = connectionString,
    DBProvider = "sqlserver",
    Name = "database",
    CommandText = 
        @"insert into dbo.Log (
            Logged, Level, Message, Username, Url, Logger, CallSite, Exception, Stacktrace, remoteAddress
        ) values(
            @Logged, @Level, @Message, @Username, @Url, @Logger, @CallSite, @Exception, @Stacktrace, @RemoteAddress
        );"
};
dbTarget.Parameters.Add(new DatabaseParameterInfo("@logged", "${date}"));
dbTarget.Parameters.Add(new DatabaseParameterInfo("@level", "${level}"));
dbTarget.Parameters.Add(new DatabaseParameterInfo("@message", "${message}"));
dbTarget.Parameters.Add(new DatabaseParameterInfo("@username", "${identity}"));
dbTarget.Parameters.Add(new DatabaseParameterInfo("@url", "${aspnet-request:serverVariable=HTTP_URL}${aspnet-request:queryString}"));
dbTarget.Parameters.Add(new DatabaseParameterInfo("@remoteAddress", "${aspnet-request:serverVariable=REMOTE_ADDR}:${aspnet-request:serverVariable=REMOTE_PORT}"));
dbTarget.Parameters.Add(new DatabaseParameterInfo("@logger", "${logger}"));
dbTarget.Parameters.Add(new DatabaseParameterInfo("@callSite", "${callsite}"));
dbTarget.Parameters.Add(new DatabaseParameterInfo("@exception", "${exception:format=tostring}"));
dbTarget.Parameters.Add(new DatabaseParameterInfo("@stacktrace", "${stacktrace:format=DetailedFlat}"));
config.AddTarget("database", dbTarget);
var rule = new LoggingRule("*", dbTarget);
config.LoggingRules.Add(rule);
LogManager.Configuration = config;
InternalLogger.LogFile = internalLogFile;

Internal logger works fine, but common logger does not. What I missed in configuring?

score 2 · Accepted Answer · answered Sep 22 '16 at 07:20

As for as I understood NLog's source code, if you don't provide Minimum log level in LoggingRule's constructure, LogLevel.Trace will not be used as minimum log level. But I expected that it will. Actually, seems like it's a bug in source: there is no EnableLoggingForLevels call (all LoggingRule have EnableLoggingForLevels call but this). So, the fix of my problem is just one parameter in constructor:

var rule = new LoggingRule("*", LogLevel.Trace, dbTarget);

instead of

var rule = new LoggingRule("*", dbTarget);

Now all exception will be logged and code works fine.

score 0 · Answer 2 · answered Aug 15 '16 at 17:08

You need to register NLog.Web also in C#, this is needed for ${aspnet-request} etc.

var extensionAssembly = Assembly.LoadFrom("nlog.web");
ConfigurationItemFactory.Default.RegisterItemsFromAssembly(extensionAssembly);

When using the XML config file, then auto loading is used (not yet in .NET Core).

This issue should be also visible in the internal log.

Configuring NLog programmatically

2 Answers2