Google.Cloud.Logging.Log4Net

Google.Cloud.Logging.Log4Net is a .NET client library to integrate Google Cloud Logging with log4net.

Note: This documentation is for version 4.4.0 of the library. Some samples may not work with other versions.

Installation

Install the Google.Cloud.Logging.Log4Net package from NuGet. Add it to your project in the normal way (for example by right-clicking on the project in Visual Studio and choosing "Manage NuGet Packages...").

Authentication

When running on Google Cloud, no action needs to be taken to authenticate.

Otherwise, the simplest way of authenticating your API calls is to set up Application Default Credentials. The credentials will automatically be used to authenticate. See Set up Application Default Credentials for more details.

Alternatively, credentials can be provided when configuring GoogleStackdriverAppender. See the configuration guide for details, specifically the CredentialFile and CredentialJson options.

Getting started

See the configuration guide for details of all GoogleStackdriverAppender configuration options.

ASP.NET

Add the log4net section to the Web.config file:

<configuration>
  <configSections>

    <!-- Other configSection item -->

    <!-- Specify a configuration section for log4net -->
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" />
  </configSections>

  <!-- The log4net configuration -->
  <log4net>
    <appender name="CloudLogger" type="Google.Cloud.Logging.Log4Net.GoogleStackdriverAppender,Google.Cloud.Logging.Log4Net">
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%-4timestamp [%thread] %-5level %logger %ndc - %message" />
      </layout>
      <projectId value="PROJECT_ID" />
      <logId value="LOG_ID" />
    </appender>
    <root>
      <level value="ALL" />
      <appender-ref ref="CloudLogger" />
    </root>
  </log4net>

  <!-- Other configuration items -->

</configuration>

Edit the file replacing PROJECT_ID with your Google Cloud Project ID, and LOG_ID with an identifier for your application.

// Load log4net configuration from Web.config
log4net.Config.XmlConfigurator.Configure(LogManager.GetRepository(GetType().Assembly));

If executing on Google App Engine (GAE), Google Kubernetes Engine (GKE), or Google Compute Engine (GCE), then the <projectId value="PROJECT_ID" /> configuration setting can be omitted; it will be auto-detected from the platform at run-time.

Console app

Create a log4net configuration file (log4net.xml):

<?xml version="1.0" encoding="utf-8" ?>
<log4net>
  <appender name="CloudLogger" type="Google.Cloud.Logging.Log4Net.GoogleStackdriverAppender,Google.Cloud.Logging.Log4Net">
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%-4timestamp [%thread] %-5level %logger %ndc - %message" />
    </layout>
    <projectId value="PROJECT_ID" />
    <logId value="LOG_ID" />
  </appender>
  <root>
    <level value="ALL" />
    <appender-ref ref="CloudLogger" />
  </root>
</log4net>

Edit the file replacing PROJECT_ID with your Google Cloud Project ID, and LOG_ID with an identifier for your application.

Use this file to configure log4net and then log as normal:

// Configure log4net to use Google Cloud Logging from the XML configuration file.
XmlConfigurator.Configure(LogManager.GetRepository(GetType().Assembly), new FileInfo("log4net.xml"));

// Retrieve a logger for this context.
ILog log = LogManager.GetLogger(typeof(Program));
// Log some information. This log entry will be sent to Google Cloud Logging.
log.Info("An exciting log entry!");

// Flush buffered log entries before program exit.
// This is required because log entries are buffered locally before being sent to Google Cloud Logging.
// LogManager.Flush() only works in the full .NET framework (not in .NET Core):
bool flushCompleted = LogManager.Flush(10_000);
// On .NET Core, the specific repository needs to be flushed:
bool repositoryFlushCompleted = ((IFlushable)LogManager.GetRepository(GetType().Assembly)).Flush(10_000);