Chapter 24: Jenkins with GitHub, GitLab and Bitbucket

24.1 Three hosts, one Jenkins idea

By Ravindra Bagale · Last updated: 25 October 2026

Why: the problem

Think of Swiggy. One team keeps its code on GitHub. Another team, after a merger, keeps code on GitLab. A third small team uses Bitbucket because they already pay for Jira. The company has one Jenkins. Does each host need a new way of working? No. The idea is the same on all three. Jenkins clones the repo with a credential, reads the Jenkinsfile, runs the stages and reports the result back. Only three things change from host to host: the clone URL shape, the plugin that talks to the host, and the place where you create the token or webhook. Many freshers learn Jenkins with only one host. Then they join a company that uses another host, and they think they must learn Jenkins again. In this lesson you will connect the same Jenkinsfile to all three hosts and see that the stages never change.

What we will build

You will make one tiny Node.js app called menu-api with one Jenkinsfile. You will push it to three remotes: a GitHub Enterprise server inside the company, GitLab and Bitbucket. Then you will make three Pipeline jobs in one Jenkins. Each job points at a different host but uses the same Jenkinsfile. At the end you will fill a small table: host, URL shape, plugin, credential id and where the build status shows.

What: every term in plain English

• Git host — A website that stores Git repos and adds pull requests, reviews and webhooks. Examples: GitHub, GitLab, Bitbucket.
• Remote — A name in your local repo, like origin, that points to a URL on a Git host.
• Clone URL — The address Jenkins uses to download the code. It is either HTTPS or SSH.
• Jenkinsfile — A text file in the repo root. It lists the pipeline stages. Jenkins reads it after cloning.
• Pipeline script from SCM — A Jenkins job setting. It means: get the Jenkinsfile from the Git repo, not from a box on the job page.
• Branch Source plugin — A Jenkins plugin that knows one host well. There is one each for GitHub, GitLab and Bitbucket.
• Credential id — A short name, like gl-token, for a secret stored inside Jenkins. The Jenkinsfile uses only the name.
• Build status — A green tick or red cross that Jenkins sends back to the commit on the host.

How: step by step

1. Make the app folder

   mkdir -p ~/lab/menu-api && cd ~/lab/menu-api && git init -q -b main && npm init -y
   

   What it does: A new Git repo with a package.json file.

   Output

   Wrote to /home/ravi/lab/menu-api/package.json
   

2. Add one test script

   npm pkg set scripts.test="echo menu ok"
   

   What it does: A tiny test that always passes. Enough to see green.

   Output

   (no output)
   

3. Add the Jenkinsfile

   nano Jenkinsfile
   

   What it does: Paste the Jenkinsfile from Example 1 and save.

   Output

   (file saved)
   

4. Commit

   git add . && git commit -qm "menu-api first commit" && git log --oneline
   

   What it does: One commit to push to all three hosts.

   Output

   4c1a9e2 menu-api first commit
   

5. Add three remotes

   git remote add ghe https://ghe.shop.internal/food/menu-api.git && git remote add gl https://gitlab.com/shop-food/menu-api.git && git remote add bb https://bitbucket.org/shopfood/menu-api.git && git remote -v
   

   What it does: One local repo, three hosts. Each remote has its own name.

   Output

   bb   https://bitbucket.org/shopfood/menu-api.git (fetch)
   ghe  https://ghe.shop.internal/food/menu-api.git (fetch)
   gl   https://gitlab.com/shop-food/menu-api.git (fetch)
   

6. Push to each host

   git push -u ghe main && git push -u gl main && git push -u bb main
   

   What it does: The same commit now lives on three hosts.

   Output

   To https://gitlab.com/shop-food/menu-api.git
    * [new branch]      main -> main
   

7. Create one Pipeline job per host

   New Item > menu-api-gl > Pipeline > Pipeline script from SCM > Git > paste the URL > pick credential > Script Path: Jenkinsfile
   

   What it does: Repeat for ghe and bb. Only the URL and credential differ.

   Output

   Job menu-api-gl created
   

Example 1: One Jenkinsfile that runs the same on every host

Stack. Node.js 20, Jenkins LTS, Docker agent

Goal. One Jenkinsfile that runs the same on every host.

Jenkinsfile

pipeline {
  agent { docker { image 'node:20-alpine' } }
  options { timestamps() }
  stages {
    stage('Checkout info') {
      steps {
        sh 'git log -1 --oneline'
        echo "Branch: ${env.BRANCH_NAME ?: 'main'}"
      }
    }
    stage('Install') { steps { sh 'npm ci || npm install' } }
    stage('Test')    { steps { sh 'npm test' } }
  }
  post {
    success { echo 'menu-api is green' }
    failure { echo 'menu-api is red, open the console' }
  }
}

What each line does

• agent { docker { image 'node:20-alpine' } } — Every stage runs inside a Node 20 container. Same Node on every host job.
• options { timestamps() } — Adds a time to every console line. Helps you see which step is slow.
• sh 'git log -1 --oneline' — Prints the commit Jenkins cloned. Proves which code it built.
• env.BRANCH_NAME ?: 'main' — BRANCH_NAME is set only in Multibranch jobs. In a normal job we print main.
• sh 'npm ci || npm install' — npm ci needs a lock file. If there is none, npm install runs.
• post { success ... failure ... } — Runs after all stages. Good place for messages and alerts.

Green output

Started by user Ravi
Cloning repository https://gitlab.com/shop-food/menu-api.git
 > git fetch --tags --force --progress -- https://gitlab.com/shop-food/menu-api.git
Checking out Revision 4c1a9e2 (refs/remotes/origin/main)
[Pipeline] stage (Checkout info)
+ git log -1 --oneline
4c1a9e2 menu-api first commit
Branch: main
[Pipeline] stage (Test)
menu ok
menu-api is green
Finished: SUCCESS

Expected result. All three jobs print the same commit 4c1a9e2 and finish green. Only the Cloning line shows a different URL.

Example 2: See the only real difference: the URL shape for each host

Stack. Git CLI on the Jenkins agent

Goal. See the only real difference: the URL shape for each host.

hosts.txt

Host                URL (HTTPS)                                         URL (SSH)
GitHub Enterprise   https://ghe.shop.internal/food/menu-api.git          git@ghe.shop.internal:food/menu-api.git
GitLab              https://gitlab.com/shop-food/menu-api.git           git@gitlab.com:shop-food/menu-api.git
Bitbucket Cloud     https://bitbucket.org/shopfood/menu-api.git         git@bitbucket.org:shopfood/menu-api.git

check-urls.sh

#!/usr/bin/env bash
set -euo pipefail
for r in ghe gl bb; do
  url=$(git remote get-url "$r")
  echo "== $r -> $url"
  git ls-remote "$r" refs/heads/main
done

What each line does

• git remote get-url "$r" — Prints the URL saved for that remote name.
• git ls-remote "$r" refs/heads/main — Asks the host for the commit of main without cloning. Jenkins does the same first.
• set -euo pipefail — Stop the script at the first failure, so a bad login is not hidden.
• git@host:owner/repo.git — SSH shape. Note the colon after the host, not a slash.
• https://host/owner/repo.git — HTTPS shape. Needs a username and a token.

Green output

== ghe -> https://ghe.shop.internal/food/menu-api.git
4c1a9e2b7f0d1e3a5c6b8d9e0f1a2b3c4d5e6f70    refs/heads/main
== gl -> https://gitlab.com/shop-food/menu-api.git
4c1a9e2b7f0d1e3a5c6b8d9e0f1a2b3c4d5e6f70    refs/heads/main
== bb -> https://bitbucket.org/shopfood/menu-api.git
4c1a9e2b7f0d1e3a5c6b8d9e0f1a2b3c4d5e6f70    refs/heads/main

Expected result. The same commit id comes back from all three hosts. If ls-remote works on the Jenkins machine, the Jenkins clone will also work.

Example 3: Install the host plugins with the Jenkins CLI and confirm they load

Stack. Jenkins in Docker

Goal. Install the host plugins with the Jenkins CLI and confirm they load.

install.sh

#!/usr/bin/env bash
set -euo pipefail
docker exec jenkins jenkins-plugin-cli --plugins git workflow-aggregator gitlab-branch-source cloudbees-bitbucket-branch-source
docker restart jenkins
sleep 40
docker exec jenkins ls /var/jenkins_home/plugins | grep -E "branch-source.jpi$"

UI step for GitHub

Manage Jenkins > Plugins > Available plugins
Search: GitHub Branch Source
Tick it > Install > Restart Jenkins when no jobs are running

What each line does

• git — The base Git plugin. Every host needs it.
• workflow-aggregator — The Pipeline plugin set. Gives you Jenkinsfile support.
• gitlab-branch-source — Talks to GitLab: projects, merge requests, pipeline status.
• cloudbees-bitbucket-branch-source — Talks to Bitbucket Cloud and Bitbucket Data Center.
• GitHub Branch Source (UI) — Talks to GitHub and GitHub Enterprise: repos, PRs, status checks. Here we install it from the Plugins page.
• jenkins-plugin-cli — The official tool inside the Jenkins image to install plugins by name.
• docker restart jenkins — New plugins load only after a restart.

Green output

Done
jenkins
cloudbees-bitbucket-branch-source.jpi
gitlab-branch-source.jpi
(after the UI install, the GitHub one shows too)

Expected result. Manage Jenkins > Plugins > Installed shows all three. Now each host has its own source type in New Item.

Verify: did it work?

1. Check each job cloned the same commit

   for j in menu-api-ghe menu-api-gl menu-api-bb; do curl -s -u ravi:$JENKINS_TOKEN "http://localhost:8080/job/$j/lastBuild/api/json?tree=result" ; echo " $j"; done
   

   What it does: Asks Jenkins for the last result of each job.

   Output

   {"result":"SUCCESS"} menu-api-ghe
   {"result":"SUCCESS"} menu-api-gl
   {"result":"SUCCESS"} menu-api-bb
   

2. Check git works from the agent

   docker exec jenkins git ls-remote https://gitlab.com/shop-food/menu-api.git HEAD
   

   What it does: If this fails, Jenkins cannot clone either.

   Output

   4c1a9e2b7f0d1e3a5c6b8d9e0f1a2b3c4d5e6f70    HEAD
   

When it is red 1

ERROR: Error cloning remote repo 'origin'
hudson.plugins.git.GitException: Command "git fetch" returned status code 128:
remote: HTTP Basic: Access denied

Cause. The job has no credential, or the token is wrong or expired.

Fix, step by step

1. Open the job and pick a credential in the Git section.
2. Test the same token with git ls-remote from your laptop.
3. Make a new token if it has expired.

When it is red 2

ERROR: Unable to find Jenkinsfile from git https://bitbucket.org/shopfood/menu-api.git

Cause. The file is missing on that branch, or the Script Path has a typo.

Fix, step by step

1. Run git ls-tree main --name-only on your laptop.
2. Check the file name is exactly Jenkinsfile, with capital J.
3. Fix Script Path if the file lives in a sub folder.

When it is red 3

fatal: unable to access 'https://ghe.shop.internal/food/menu-api.git/': SSL certificate problem: unable to get local issuer certificate

Cause. The company GitHub Enterprise uses an inside certificate that the Jenkins Java and Git do not trust.

Fix, step by step

1. Get the company root CA file from the IT team.
2. Add it to the agent trust store and the Git config http.sslCAInfo.
3. Never turn off SSL checks as a fix.

Cleanup

1. Delete the three lab jobs

   for j in menu-api-ghe menu-api-gl menu-api-bb; do curl -s -X POST -u ravi:$JENKINS_TOKEN "http://localhost:8080/job/$j/doDelete"; done
   

   What it does: Removes the jobs. The repos stay on the hosts.

   Output

   (no output)
   

2. Remove the extra remotes

   git remote remove ghe && git remote remove bb
   

   What it does: Keeps your laptop repo simple.

   Output

   (no output)
   

Practice tasks

Homework: try at home

Recap

• The Jenkins idea is the same on GitHub, GitLab and Bitbucket.
• Only the URL, credential and host plugin change.
• git ls-remote on the agent is the fastest clone test.
• Install the Branch Source plugin for each host you use.
• Keep tokens in Jenkins credentials and use them by id.

FAQ

Do I need three Jenkins servers for three hosts?

No. One Jenkins can build from all of them.

Is GitHub Enterprise the same as GitHub?

The same product, but on the company network. URLs use the company host name.

Can I use the plain Git plugin without the Branch Source plugin?

Yes, for simple jobs. You lose PR discovery and status checks.

Which host is best for Jenkins?

All work well. Pick the one your company already uses.

Does Bitbucket Data Center differ from Bitbucket Cloud?

Yes, URLs and tokens differ, but the same plugin supports both.

Interview questions

1. How do you connect Jenkins to different Git hosts?

   Install the host Branch Source plugin, add a credential, use the clone URL in the job. The Jenkinsfile does not change.

2. What is the difference between Pipeline script and Pipeline script from SCM?

   Pipeline script keeps the code in the job page. From SCM reads the Jenkinsfile from Git, so it is versioned and reviewed.

3. How do you debug a clone failure?

   Run git ls-remote with the same URL and credential on the agent. Read the status code 128 message.

4. Why keep one Jenkinsfile for all hosts?

   So the build is the same everywhere. Only the source settings change.

5. How do you trust a company GitHub Enterprise certificate?

   Add the company root CA to the agent trust store. Never disable SSL verification.

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