Where is the log file in log4net? - asp.net-mvc

Question

I've got the following entries in my Web.config file in an asp.net mvc application:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" />
...
</configSections>
<log4net>
<appender name="PublicAccessAppender" type="log4net.Appender.RollingFileAppender">
<datePattern value="'C:\Users\my_user_name\Documents\Temp\logs\public-access.'yyyy-MM-dd'.log'" />
<staticLogFileName value="false" />
<appendToFile value="true" />
<rollingStyle value="Date" />
<maxSizeRollBackups value="5" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger - %message%newline" />
</layout>
</appender>
<root>
<level value="DEBUG" />
<appender-ref ref="PublicAccessAppender" />
</root>
</log4net>
...
</configuration>
I hope it's pretty self-explanatory what I'm trying to achieve, but when I run the application (hosted in IIS), I get no log file. FWIW, the directory hierarchy exists up to Temp folder, and I'd like log4net to generate the rest of the directories/files in the path.
I've added the log4net nuget package to my application, and I'm logging with the INFO level.
What am I missing here?

Answer 1

I think you can't put full path into datePattern, there must be just YYYYmmdd and things like that. Put the file path into file element:
<file value="C:\Users\my_user_name\Documents\Temp\logs\public-access.log" />
<datePattern value="yyyyMMdd" />
<preserveLogFileNameExtension value="true" />
The last element forces to put datePattern before the .log extension which was probably your original goal..

Answer 2

Here's the working appender configuration:
<appender name="PublicAccessAppender" type="log4net.Appender.RollingFileAppender">
<file value="C:\temp\my_user_name\Documents\Temp\logs\app.log" />
<datePattern value=".yyyy-MM-dd" /><!-- can be omitted as it's the default datePattern value -->
<rollingStyle value="Date" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger - %message%newline" />
</layout>
</appender>
Note to readers struggling with log4net configuration: asp.net hosted in IIS pretty much has 0 write permssions, so the issue you're most likely struggling with is that your web app simply doesn't have permission to write to the log file.
That's what was happening for me, and I noticed it by inspecting the contents of log4net.LogManager.GetRepository().ConfigurationMessages in the debugger after calling .Configure().
I followed this post to give my web app the necessary persmissions to write to the log file (namely Read/Write/Modify).