Github Actions: Rerun Maven with Log4j on Debug – A Step-by-Step Guide

Introduction

Are you tired of dealing with Maven build failures in your Github Actions pipeline? Do you struggle to troubleshoot issues due to lack of visibility into the build process? Look no further! In this article, we’ll show you how to rerun Maven with Log4j on debug mode, giving you the visibility you need to identify and fix build issues quickly and efficiently.

Why Rerun Maven with Log4j on Debug?

Rerunning Maven with Log4j on debug mode can be a game-changer for your CI/CD pipeline. Here are just a few reasons why:

• Debugging made easy: With Log4j on debug mode, you’ll get detailed logs of the build process, making it easier to identify and fix issues.
• Faster issue resolution: By rerunning Maven with Log4j on debug, you can quickly reproduce and debug issues, reducing the time spent on troubleshooting.
• Improved pipeline reliability: By identifying and fixing build issues quickly, you can improve the reliability of your pipeline and reduce the risk of failed builds.

Prerequisites

Before we dive into the tutorial, make sure you have the following:

• A Github repository with a Maven-based project
• A Github Actions pipeline set up for your repository
• Basic knowledge of Maven and Log4j

Step 1: Update your pom.xml

The first step is to update your `pom.xml` file to include the Log4j dependency. Add the following code to your `pom.xml` file:

<dependency>
  <groupId>org.apache.logging.log4j</groupId>
  <artifactId>log4j-core</artifactId>
  <version>2.14.1</version>
</dependency>
<dependency>
  <groupId>org.apache.logging.log4j</groupId>
  <artifactId>log4j-api</artifactId>
  <version>2.14.1</version>
</dependency>

Make sure to update the version number to the latest available version.

Step 2: Configure Log4j

Next, you need to configure Log4j to output debug logs. Create a new file called `log4j2.xml` in the `src/main/resources` directory of your project. Add the following code to the file:

<Configuration>
  <appenders>
    <ConsoleAppender name="Console" target="SYSTEM_OUT">
      <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
    </ConsoleAppender>
  </appenders>
  <loggers>
    <root level="DEBUG">
      <appender-ref ref="Console"/>
    </root>
  </loggers>
</Configuration>

This configuration sets up Log4j to output debug logs to the console.

Step 3: Update your Github Actions workflow

Now, you need to update your Github Actions workflow to rerun Maven with Log4j on debug mode. Add the following code to your `yaml` file:

name: Maven Build

on:
  push:
    branches:
      - main

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v2
      - name: Run Maven build
        run: |
          mvn clean package -X
          echo "##vso[task.setvariable variable=MAVEN_LOG;]$(cat target/surefire-reports/TEST-com.example.MyTest.log)"

This code runs the Maven build with the `-X` flag, which enables debug logging. The `echo` command outputs the debug log to the console.

Step 4: Rerun the Build with Debug Logs

Now, let’s rerun the build with debug logs. Go to your Github Actions pipeline and click on the “Re-run” button.

Once the build is complete, you’ll see the debug logs in the console output.

Step 5: Analyze the Debug Logs

The final step is to analyze the debug logs to identify the issue. Look for error messages or exceptions that may indicate the cause of the build failure.

For example, if you see an error message like this:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.22.2:test (default-test) on project my-project: There are test failures.
[ERROR] 
[ERROR] Please refer to /home/runner/work/my-project/my-project/target/surefire-reports for the individual test results.
[ERROR] -> [Help 1]

You can investigate the test failures by looking at the individual test results in the `target/surefire-reports` directory.

Troubleshooting Tips

Here are some troubleshooting tips to help you get the most out of rerunning Maven with Log4j on debug:

• Check the debug logs carefully: Make sure to carefully read through the debug logs to identify the root cause of the issue.
• Use a log analyzer tool: Consider using a log analyzer tool like Loggly or Sumo Logic to help you parse and analyze the debug logs.
• Test individual components: If the issue is related to a specific component, try testing it individually to isolate the issue.
• Check the Maven version: Make sure you’re using the latest version of Maven and Log4j to avoid compatibility issues.

Conclusion

Rerunning Maven with Log4j on debug mode can be a powerful tool in your Github Actions pipeline. By following the steps outlined in this article, you can quickly identify and fix build issues, improving the reliability and efficiency of your pipeline.

Remember to carefully analyze the debug logs, test individual components, and troubleshoot issues methodically to get the most out of this approach.

Tip	Description
Use a consistent logging format	Use a consistent logging format across your application to make it easier to analyze logs.
Log at the right level	Log at the right level (DEBUG, INFO, ERROR, etc.) to avoid overwhelming logs and make it easier to identify issues.
Use a log aggregator	Use a log aggregator like ELK or Splunk to collect and analyze logs from multiple sources.

We hope you found this article helpful! If you have any questions or need further assistance, please don’t hesitate to ask.

Frequently Asked Question

Here are some frequently asked questions about Github Actions, Rerun Maven with Log4j on Debug. Read on to find out the answers!