Logging Configuration

Elliott API uses aspnetcore + nlog for logging. The configuration can be configured with the nlog.config. There are two main sections targets and rules. 

Targets 

Targets specify the destination log entries will be written to.

Exampe - the following entry is the default target for database trace.

    <target name="databaestracefile" xsi:type="AsyncWrapper" queueLimit="5000" overflowAction="Discard">
      <target
        xsi:type="File"
        layout="${longdate} ${message}"
        fileName="logs/database/database.txt"
        archiveFileName="logs/database/database.{#####}.txt"
        archiveAboveSize="10240000"
        archiveNumbering="Sequence"
        maxArchiveFiles="10"
        concurrentWrites="true"
        keepFileOpen="false" />
    </target>

• type - specify the type of the target, in this example, log entries will be written to a file. You can also specify other targets such as email or to network. For more information, you can look up nlog documentation.
• fileName -  specify the file to write log entries to. You can use absolute path, or relative path. Relative path is relative to the path of the Elliott API root folder
• archiveFileName - specify the fileName to use when the log file is archived
• archiveAboveSize - specify the size the log file will be archived
• archiveNumbering - specify how archive file will be named.
• maxArchiveFiles - specify the number of archive files to keep. 

Rules

Rules specify the what will be logged, and where it will be logged.

Example:- following entry will log all log entries output by any classes in "ElliottApi.Infrastructure.Owin.ApiLoggingMiddleware" to the apitracetarget. 

 <logger enabled="true" name="ElliottApi.Infrastructure.Owin.ApiLoggingMiddleware.*" level="Trace" writeTo="apitracefile" final="true" />  

• enabled - specify whether this rule is enabled
• name - specify the logger name. The logger names are usually the fully qualified namespace + class name in the Elliott API. You can append the "*" wildcard character at the end of a namespace to include all logger in a related namespace.
• level - specify the level of logging that will be included
• writeTo - the target to write to
• final - if true, it will stop matching on further rule

Elliott API is distributed with a set of common rules that provide extensive logging that's intended to provide detail logging when it's first setup. Prior to going to production, you may choose to adjust the loggers to only log errors and re-enable detail logging when you need to troubleshoot problems. The following are the default loggers, at the minimum, you will want to enable the logger than writes to "errorfile" (bolded in the example below).

    <logger enabled="true" name="ElliottApi.Infrastructure.Data.*" level="Trace" writeTo="databaestracefile" final="true" />
    <logger enabled="true" name="ElliottApi.Infrastructure.Owin.ApiLoggingMiddleware.*" level="Trace" writeTo="apitracefile" final="true" />
    <logger enabled="true" name="ElliottApi.Infrastructure.Providers.Nmi.*" level="Trace" writeTo="nmitracefile" final="true" />
    <logger enabled="true" name="*" minlevel="Error" writeTo="errorfile" />
    <logger enabled="true" name="*" minlevel="Trace" writeTo="logfile" />  

API Logging Configuration

The default rule logs all API raw requests responses to the apitracefile target. 

<logger enabled="true" name="ElliottApi.Infrastructure.Owin.ApiLoggingMiddleware.*" level="Trace" writeTo="apitracefile" final="true" />  

The "name" follows this pattern " ElliottApi.Infrastructure.Owin.ApiLoggingMiddleware.{route-where-slash-is-replaced-by-dash}". You can use it to target a specific API. For example, if you are only interested in the log messages for "order/search" route. You can have the following rule entry:

  <logger enabled="true" name="ElliottApi.Infrastructure.Owin.ApiLoggingMiddleware.order-search*" level="Trace" writeTo="apitracefile" final="true" />    

You can also target multiple routes by having multiple entries that target different routes. For example, to target "order/search" and "vendor/search" routes:

  <logger enabled="true" name="ElliottApi.Infrastructure.Owin.ApiLoggingMiddleware.order-search*" level="Trace" writeTo="apitracefile" final="true" />     

  <logger enabled="true" name="ElliottApi.Infrastructure.Owin.ApiLoggingMiddleware.vendor-search*" level="Trace" writeTo="apitracefile" final="true" />