1. Pipeline Utility Steps

• Concept: Provides commonly used utility functions in Jenkins Pipeline
• Key Features:
  • readJSON, writeJSON → Read/write JSON files
  • readYaml, writeYaml → Read/write YAML files
  • zip, unzip, untar and other compression-related features
• Example

def data = readJSON file: 'config.json'
echo "버전: ${data.version}"

Use Case: Read files like config.json/values.yaml in a pipeline to adjust build options depending on the environment.

---

2. Pipeline: Stage Step

• Concept: A plugin that enables the use of stage() in Declarative/Scripted Pipelines
• Role: Visually displays stages in the pipeline UI
• Example

stage('Build') {
    sh 'mvn clean package'
}

Use Case: Divide build, test, and deploy stages to gain visibility in the Jenkins UI/Blue Ocean.

---

3. Blue Ocean

• Concept: A modern UI plugin dedicated to Jenkins Pipeline

• Features:

  • Intuitive pipeline visualization
  • Per-branch view for multi-branch pipelines
  • Build logs displayed broken down by stage

• Example:

  Instead of the classic UI, it presents pipelines in a “timeline format” in a clean, visual way.

  Use Case: Get an at-a-glance overview of complex pipeline execution.

---

4. Swarm Plugin

• Concept: A plugin that automatically registers Jenkins Agents with the Controller
• Features:
  • Run the Swarm Client on an agent server → automatically connects to the Controller
  • Dynamically expand the agent pool
• Example

java -jar swarm-client.jar -master http://jenkins:8080 -username user -password pass

Use Case: Easily manage a large number of build agents (especially in VM-based environments).

---

5. Node and Label Parameter Plugin

• Concept: Allows you to choose which node or label to run a build on at execution time
• Features:
  • Specify the build node as a parameter
  • Run only on specific labels (e.g., docker, windows)
• Example

parameters {
    label(name: 'NODE_LABEL', defaultValue: 'docker', description: '빌드 실행 노드')
}
node(params.NODE_LABEL) {
    stage('Build') {
        sh 'make build'
    }
}

Use Case: Windows-only or Linux-only builds, running on specific GPU nodes.

---

6. Monitoring Plugin

• Concept: Provides system performance monitoring for the Jenkins Controller and Nodes

• Available Metrics: JVM memory, CPU, thread count, system load, GC

• Example: Access the /monitoring page in the Jenkins UI → real-time monitoring

  Use Case: Check Jenkins server health, performance tuning, and incident response.

---

7. Prometheus Metrics Plugin

• Concept: A plugin that exposes Jenkins metrics to Prometheus

• Features:

  • Build success/failure counts
  • Queue length, executor utilization
  • Node status, job execution time

• Example: http://jenkins:8080/prometheus → Register as a Prometheus scrape target

  Use Case: Visualize Jenkins build status and node resource usage on a Grafana dashboard.

---

8. Configuration as Code (JCasC)

• Concept: Manages the entire Jenkins configuration (security, nodes, plugins, credentials, etc.) as YAML files
• Features:
  • Store in Git to ensure reproducibility
  • Apply once when setting up a new server to restore an identical environment
• Example (jenkins.yaml)

jenkins:
  systemMessage: "Managed by JCasC"
  numExecutors: 0
credentials:
  system:
    domainCredentials:
      - credentials:
          - string:
              id: "slack-token"
              secret: "${SLACK_TOKEN}"

Use Case: Automatically restore configuration when reinstalling, migrating, or upgrading a Jenkins server.

---

9. Workspace Cleanup Plugin

• Concept: A plugin that automatically cleans up the workspace after a job runs
• Features:
  • Guarantees a clean state on every build
  • Saves disk space on nodes
• Example

post {
    always {
        cleanWs()
    }
}

Use Case: Prevents build artifacts or cache files from accumulating and filling up the disk.

---

10. Throttle Concurrent Builds Plugin

• Concept: Limits the number of concurrent executions for a specific job or group of jobs
• Features:
  • Can be limited per node or across all of Jenkins
  • Group jobs by category for control
• Example

pipeline {
  agent any
  options {
    throttleConcurrentBuilds(
      maxConcurrentPerNode: 1,
      maxConcurrentTotal: 2,
      categories: ['heavy-tests']
    )
  }
}

Use Case: Prevent heavy integration tests or external API load tests from running multiple instances simultaneously.

---

Summary

Plugin	Role
Pipeline Utility Steps	File read/write utilities for JSON/YAML, etc.
Pipeline: Stage Step	Provides Stage UI (pipeline step separation)
Blue Ocean	Pipeline visualization UI
Swarm Plugin	Automatic agent registration / pool management
Node and Label Parameter	Select execution on a specific node/label
Monitoring Plugin	Jenkins server/node performance monitoring
Prometheus Metrics	Expose Jenkins metrics to Prometheus/Grafana
Configuration as Code	Manage Jenkins configuration as YAML code
Workspace Cleanup	Workspace cleanup and disk space savings
Throttle Concurrent Builds	Limit the number of concurrent job executions