Logging doesn't work if mail target added to NLog configuration for web application

[dimrun]

Type: Bug

NLog version: 4.3.2

Platform: .Net 3.5 / .Net 4.0 / .Net 4.5 / Mono 4 / Silverlight 4 / Silverlight 5

Current NLog config (xml or C#, if relevant):
nothing special, just mail target added to web.config

In case of a BUG:

• What is the current result?
  Exception occurs:

---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.ArgumentException: exePath must be specified when not running inside a stand alone exe.
  at System.Configuration.ConfigurationManager.OpenExeConfigurationImpl(ConfigurationFileMap fileMap, Boolean isMachine, ConfigurationUserLevel userLevel, String exePath, Boolean preLoad)
  at System.Configuration.ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel userLevel)
  at NLog.Targets.MailTarget.get_MailSettings()

• What is the expected result?
  No errors
• Stack trace:

---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.ArgumentException: exePath must be specified when not running inside a stand alone exe.
  at System.Configuration.ConfigurationManager.OpenExeConfigurationImpl(ConfigurationFileMap fileMap, Boolean isMachine, ConfigurationUserLevel userLevel, String exePath, Boolean preLoad)
  at System.Configuration.ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel userLevel)
  at NLog.Targets.MailTarget.get_MailSettings()
  --- End of inner exception stack trace ---
  at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
  at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
  at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
  at System.Reflection.RuntimePropertyInfo.GetValue(Object obj, Object[] index)
  at NLog.Internal.ObjectGraphScanner.ScanProperties[T](List`1 result, Object o, Int32 level, HashSet`1 visitedObjects)
  at NLog.Internal.ObjectGraphScanner.ScanProperties[T](List`1 result, Object o, Int32 level, HashSet`1 visitedObjects)
  at NLog.Internal.ObjectGraphScanner.ScanPropertiesList[T](List`1 result, IEnumerable`1 elements, Int32 level, HashSet`1 visitedObjects)
  at NLog.Internal.ObjectGraphScanner.ScanProperties[T](List`1 result, Object o, Int32 level, HashSet`1 visitedObjects)
  at NLog.Internal.ObjectGraphScanner.FindReachableObjects[T](Object[] rootObjects)
  at NLog.Config.LoggingConfiguration.ValidateConfig()
  at NLog.Config.LoggingConfiguration.InitializeAll()
  at NLog.LogFactory.get_Configuration()
  at NLog.LogFactory.GetLogger(LoggerCacheKey cacheKey)
  at NLog.LogFactory.GetLogger(String name)
  at NLog.LogManager.GetLogger(String name)

Possible reason / fix:

When we read SMTP configuration (MailTarget.MailSettings property) we don't take into account that it can be executed in scope of web application

Current code:

 _currentailSettings = System.Configuration.ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None).GetSection("system.net/mailSettings/smtp") as SmtpSection;

A special switch for this case should be added. Something like this:
http://stackoverflow.com/questions/5629209/how-to-replace-openexeconfiguration-in-a-web-context-asp-net-mvc-1

[ivanpointer]

I don't believe this problem existed in 4.3.1, and appears to have been introduced with 4.3.2. Our organization is sticking with 4.3.1 until this is straightened out.

[ivanpointer]

This also includes WCF applications (I know, they're technically "web" applications).

[304NotModified]

This bug is indeed introduced in 4.3.2. Will fix this in 4.3.3. Any idea how to unit test this?

bug introduced in #1402

[304NotModified]

I think the code in http://stackoverflow.com/questions/5629209/how-to-replace-openexeconfiguration-in-a-web-context-asp-net-mvc-1 is problematic as it uses system.web, and we don't want a dependency to system.web from NLog. Any thoughts @ivanpointer ?

[krazyest]

note that if smtpDeliveryMethod="network" is used, it mitigates the issue and the exePath exception is not shown, but Nlog does not log anymore

[304NotModified]

ATM I'm working on a fix

[304NotModified]

This is fixed in NLog 4.3.3. Also the code is more robust - no crash or disabled logging when there are troubles reading the "from" from the SMTP config.

https://www.nuget.org/packages/NLog/4.3.3

[ivanpointer]

Thank you! I just now saw the notes and will pull down 4.3.3 to verify.

Thanks again!

[304NotModified]

👍