NLog.Contrib.Targets.LogEntries

Simple LogEntries NLog target that works properly on Linux.

• Uses SSL.
• Multiplexes all targets (even with different tokens) into the same connection.
• It is asynchronous.
• The token can be set in an environment variable.
• The UTF8 conversion is done using a static array and not creating arrays dynamically.
• It does not do additional string concatenations to format the data in the expected protocol format.
• On socket error, it does not lose the buffered serialized entry.
• The official NLog target from Rapid7 uses an API that is not supported in Linux (IOControl). Since the KeepAlive is not configured to a shorter interval, in some cloud environments the connections gets half-open after some minutes of inactivity. This component assumes that if the connection has been idle for more than 30 seconds, the connection is dead and a new one is created. Since all the targets in the application are multiplexed through the same connection, this situation may never happen in production.

Installation

It is available in Nuget: NLog.Contrib.Targets.LogEntries

dotnet add package NLog.Contrib.Targets.LogEntries

Usage

There is two ways of providing the token. The traditional one, providing the token hardcoded in the .config file using the token parameter in the target configuration; and also it is possible to provide the name of an enviroment variable in which the token is stored with the tokenEnvVar parameter, which is handy for using it in Docker containers.

Providing the token directly in the configuration

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xsi:schemaLocation="NLog NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <extensions>
    <add assembly="NLog.Contrib.Targets.LogEntries"/>
  </extensions>
  <targets>
    <target name="logentries" type="LogEntries" token="[your LogEntries token]"
            layout="${date:format=ddd MMM dd} ${time:format=HH:mm:ss} ${date:format=zzz yyyy} ${logger} : ${LEVEL}, ${message}"/>
  </targets>
  <rules>
    <logger name="*" minlevel="Trace" writeTo="logentries" />
  </rules>
</nlog>

Providing the token in an environment variable

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xsi:schemaLocation="NLog NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <extensions>
    <add assembly="NLog.Contrib.Targets.LogEntries"/>
  </extensions>
  <targets>
    <target name="logentries" type="LogEntries" tokenEnvVar="[ENV VAR NAME]"
            layout="${date:format=ddd MMM dd} ${time:format=HH:mm:ss} ${date:format=zzz yyyy} ${logger} : ${LEVEL}, ${message}"/>
  </targets>
  <rules>
    <logger name="*" minlevel="Trace" writeTo="logentries" />
  </rules>
</nlog>