Jenkinsfile per branch - Step-by-Step Execution

Process Flow - Jenkinsfile per branch

Start Jenkins Pipeline

↓

Detect current branch

↓

Load Jenkinsfile for branch

↓

Execute branch-specific pipeline

↓

Pipeline completes or fails

Jenkins detects the current branch, loads the matching Jenkinsfile, then runs the pipeline defined for that branch.

Execution Sample

Jenkins

pipeline {
  agent any
  stages {
    stage('Build') {
      steps {
        echo "Building branch ${env.BRANCH_NAME}"
      }
    }
  }
}

A simple Jenkins pipeline that prints the current branch name during the build stage.

Process Table

Step	Action	Branch Detected	Jenkinsfile Loaded	Pipeline Output
1	Start pipeline	feature/login	Jenkinsfile-feature	N/A
2	Load Jenkinsfile	feature/login	Jenkinsfile-feature	N/A
3	Execute Build stage	feature/login	Jenkinsfile-feature	Building branch feature/login
4	Pipeline completes	feature/login	Jenkinsfile-feature	Success

💡 Pipeline ends after executing branch-specific Jenkinsfile for feature/login branch.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
env.BRANCH_NAME	undefined	feature/login	feature/login	feature/login	feature/login
Jenkinsfile Loaded	none	none	Jenkinsfile-feature	Jenkinsfile-feature	Jenkinsfile-feature
Pipeline Output	none	none	none	Building branch feature/login	Success

Key Moments - 2 Insights

How does Jenkins know which Jenkinsfile to use for each branch?

Jenkins detects the current branch name (see Step 1 in execution_table) and loads the Jenkinsfile matching that branch (Step 2). This allows branch-specific pipelines.

What happens if the Jenkinsfile for a branch is missing?

The pipeline will fail to load the Jenkinsfile at Step 2, causing the build to fail early. This is why each branch should have its own Jenkinsfile or fallback.

Visual Quiz - 3 Questions

Look at the execution_table, what is the branch detected at Step 1?

A feature/login

B main

C develop

D release

💡 Hint

Check the 'Branch Detected' column at Step 1 in the execution_table.

At which step does Jenkins load the branch-specific Jenkinsfile?

A Step 1

B Step 3

C Step 2

D Step 4

💡 Hint

Look at the 'Jenkinsfile Loaded' column in the execution_table.

If the branch was 'main', how would the Jenkinsfile Loaded value change in the execution_table?

A Jenkinsfile-feature

B Jenkinsfile-main

C Jenkinsfile-develop

D No Jenkinsfile loaded

💡 Hint

The Jenkinsfile loaded matches the branch name as shown in the 'Jenkinsfile Loaded' column.

Concept Snapshot

Jenkinsfile per branch:
- Jenkins detects current branch via env.BRANCH_NAME
- Loads Jenkinsfile matching branch name
- Runs branch-specific pipeline steps
- Enables different workflows per branch
- Fails if Jenkinsfile missing for branch

Full Transcript

This visual execution shows how Jenkins runs a pipeline using a Jenkinsfile specific to the current branch. First, Jenkins detects the branch name, for example 'feature/login'. Then it loads the Jenkinsfile named for that branch, such as 'Jenkinsfile-feature'. Next, it executes the pipeline steps defined in that Jenkinsfile, here printing the branch name during the build stage. Finally, the pipeline completes successfully. If the Jenkinsfile for the branch is missing, the pipeline will fail early. This approach allows teams to customize CI/CD workflows per branch easily.