Introduction
Jenkins is one of the most widely used CI/CD tools, but beyond its common capabilities, it hides a treasure trove of powerful features that many users overlook. These rarely known features can enhance automation, debugging, and performance, especially for large-scale deployments like IoT applications. Let’s explore some of these hidden gems!
1. Jenkins Fingerprints for Artifact Tracking
Jenkins automatically tracks artifacts and dependencies across jobs using fingerprints. This allows you to trace builds and artifacts across different pipelines, which is particularly useful for IoT firmware updates and software version tracking.
- Check fingerprints in Manage Jenkins → Fingerprints
- Retrieve fingerprint details via API:
http://your-jenkins-url/job/my-job/lastSuccessfulBuild/fingerprint/ 2. Throttling Concurrent Builds
Too many simultaneous builds can slow down your system. These features lets you:
- Limit how many builds run at once
- Group jobs to share resource limits
- Prevent overload on IoT devices during firmware testing
Enable it via Manage Jenkins → Plugins → Throttle Concurrent Builds Plugin.
3. Load Balancing with Multiple Nodes
Jenkins can distribute workloads across multiple agents, preventing the master node from being overloaded. This is useful when:
- Assigning jobs to specific labels (e.g., iot-test, firmware-build)
- Using Kubernetes or Docker agents for dynamic scaling
- Reducing bottlenecks in resource-intensive builds
Set this up under Manage Jenkins → Manage Nodes and Clouds.
4. Debugging Environment Variables
Need to check available environment variables in a Jenkins build? Just add this to a script step:
env
It prints all Jenkins environment variables, such as:
- $BUILD_NUMBER → Current build number
- $WORKSPACE → Path to the job’s workspace
- $NODE_NAME → Node running the job
Alternatively, in a Groovy script:
println(env.BUILD_NUMBER)
5. Defining Jobs as Code with Jenkins Job DSL
Instead of manually creating jobs via UI, define them using Job DSL Plugin. Example:
pipelineJob('My IoT Build') {
definition {
cps {
script('''
pipeline {
agent any
stages {
stage('Build') {
steps {
echo 'Building IoT firmware...'
}
}
}
}
''')
}
}
}
This makes jobs easier to maintain and version-control.
6. Pausing New Builds Using Quiet Mode
For maintenance or debugging, pause new builds without stopping existing ones:
http://your-jenkins-url/quietDown Resume normal operations with:
http://your-jenkins-url/cancelQuietDown 7. Secure Credential Storage with Secret Text & Files
Jenkins stores credentials securely, preventing exposure in logs.
- Add Secret Text, Username & Password, or Secret File in Manage Jenkins → Manage Credentials
- Use in pipelines:
withCredentials([string(credentialsId: 'my-secret-id', variable: 'SECRET')]) {
sh 'echo $SECRET' # Secret is used but never exposed
}8. JUnit & Test Trend Reports
Jenkins can visualize test trends over time, which is useful for debugging firmware or regression tests.
Example in Jenkinsfile:
post {
always {
junit 'test-results/*.xml'
}
}Find reports in Test Result Trend in Jenkins.
9. Pipeline Replay: Edit & Rerun Pipelines Without Committing
If a pipeline fails, quickly test a fix without making a commit:
- Open a failed pipeline run
- Click Replay
- Modify the script inline and rerun it
Great for debugging without cluttering your Git history.
10. Faster Logs with WebSocket Console
Jenkins normally polls for logs, but WebSocket console improves real-time log performance.
Enable it in Manage Jenkins → Configure System → Console Output Transport → WebSocket.
Bonus: Jenkins Easter Egg - ASCII Art Butler
Run this in Manage Jenkins → Script Console:
println(Jenkins.instance.getVersion()) Older versions of Jenkins display an ASCII Jenkins butler as a fun hidden feature!
Security can be reinforced with role-based access control, secrets management, and audit trails. Additionally, built-in monitoring tools, integrations with Prometheus, and real-time logging help fine-tune performance. Leveraging these lesser-known capabilities can transform Jenkins into a robust DevOps automation engine, optimizing workflows for even the most complex deployments.
Final Thoughts
Jenkins is more than just a CI/CD tool—it’s a powerhouse of automation, debugging, and performance optimization. Beyond standard pipeline execution, it offers hidden features that can significantly enhance build efficiency, security, and monitoring. For IoT CI/CD pipelines, Jenkins provides advanced caching mechanisms, parallel execution, and resource management to speed up builds.
For more insights on Jenkins, check out the official website of Jenkins. Checkout more of our DevOps blogs here.
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