Capturing Docker Container Logs in Jenkins

You can capture the standard output from your Docker container in your Jenkins pipeline by utilizing the `docker run` command with the appropriate flags. This can be done in a scripted pipeline using Groovy.

Here’s a basic example of how you might set this up:

pipeline {
    agent any
    stages {
        stage('Build Docker Image') {
            steps {
                script {
                    // Build the Docker image
                    sh 'docker build -t my-image .'
                }
            }
        }
        stage('Run Docker Container') {
            steps {
                script {
                    // Run the container and capture the logs
                    def output = sh(script: 'docker run my-image', returnStdout: true).trim()
                    // Print the logs to Jenkins console
                    echo "Container output: ${output}"
                }
            }
        }
    }
}
    

In the `sh` command for running your container, use `returnStdout: true` to capture the output directly into a variable. Then, you can use `echo` to display it in the Jenkins logs.

Just a couple of things to watch out for:

• Container Exit Codes: Make sure to check the exit code of your container. If it’s non-zero, it indicates an error.
• Long-running Containers: If your container runs for a long time, you might want to implement a timeout or a log rotation strategy to avoid overwhelming your Jenkins logs.
• Dependencies on Docker Daemon: Ensure Jenkins has the necessary permissions to run Docker commands. Running Jenkins as a non-root user might require additional configuration.

This should give you a clear starting point! Happy coding!