GitHub - DebaratiBiswas/CICD_mvn_java: source code with java maven simple project to be integrated with cicd Jenkins for build. Github Webhook for jenkins job

source code with java maven simple project integrated with cicd Jenkins for build. Github Webhook for jenkins job trigger Steps:
Install vscode in ms store with gmail : https://apps.microsoft.com/detail/xp9khm4bk9fz7q?launch=true&mode=full&hl=en-us&gl=in&ocid=bingwebsearch
install git : https://git-scm.com/downloads/win . git is installed in C:\Program Files\Git . open git bash in the folder you need to clone.
Java code with maven build: https://github.com/jabedhasan21/java-hello-world-with-maven Install JDK 8 :
Visit the official Oracle website: JDK 8 Downloads.
You'll need to create an Oracle account to download JDK 8, as it's in the archive
Install
Installed in C:\Program Files\Java\jdk1.8.2
Set environment
Step 1: Right-click on This PC or My Computer and select Properties.
Step 2: Click Advanced system settings on the left-hand side.
Step 3: In the System Properties window, click on the Environment Variables button.
Step 4: Under System variables, scroll down and find the Path variable. Select it and click Edit.
Step 5: In the Edit Environment Variable window, click New and add the path to your JDK bin directory. This is usually: C:\Program Files\Java\jdk1.8.x_xxx\bin
Step 6: Also, add a new System variable:
Variable name: JAVA_HOME C:\Program Files\Java\jdk1.8.x_xxx
check with java -version command
Install maven :
https://www.baeldung.com/install-maven-on-windows-linux-mac#installing-maven-on-windows
install https://maven.apache.org/download.cgi zip - 3.9.9 now
Extract to C:\Program Files\Apache\Maven
right click on this pc -> advanced system settings
edit path as C:\Program Files\Apache\Maven\apache-maven-3.9.9\bin
add M2_HOME and MAVEN_HOME variable with value C:\Program Files\Apache\Maven\apache-maven-3.9.9

Add src code files in src\main\java\hello folder
Add pom.xml
Execute "mvn compile" to get target folder
"mvn package" to get war file inside target folder . Phases like validate, compile, test, and package are executed.
"mnv install" to package and install in local m2 repo. In addition to performing everything mvn package does, mvn install
also installs the packaged artifact (e.g., JAR or WAR) into the local Maven repository (usually located at ~/.m2/repository on your system).

Why is the Reduced pom.xml Generated?
When creating a shaded JAR, Maven combines the project's code with its dependencies into one executable JAR file, which can be distributed without worrying about external dependency management. However, the original pom.xml still lists all the dependencies that were packaged into the JAR. Including these dependencies in future projects would cause them to be added again, which might result in duplicate classes or conflicts.

To avoid this, Maven generates a reduced pom.xml, which:

Excludes the dependencies that were already included (shaded) in the final JAR.
Retains only the necessary dependencies that are still required by consumers of the shaded JAR.

git config --global user.email "biswas1396@gmail.com"
git config --global user.email "biswas1396@gmail.com"
git add .
git status
git commit -m "message"

Jenkins setup and pipeline execution

download jenkins: https://www.jenkins.io/download/#downloading-jenkins 2.481
https://www.jenkins.io/doc/book/installing/windows/
install in C:\Program Files\Jenkins\
am running it as local <- no admin username n pwd needed
install java 17 or 21 as it is n=only supported by jenkins
https://www.oracle.com/java/technologies/javase/jdk21-archive-downloads.html
choose .exe
install finish find password in C:\Program Files\Jenkins\jenkins.err and paste in jenkins login page in web localhost:8080

install all plugins
give jenkins username and pwd with email
jenkins dashboard appears

##Setup Jenkins
add jenkins file with jdk and maven version as named in manage jenkins <-- tools ; with its local javahome and maven home paths
in plugins check for git and pipeline
Create a New Pipeline Job:

In Jenkins, click on New Item.
Choose Pipeline and give it a name (e.g., "Maven Build"). here - githubrepo_pipeline
Under the Pipeline section, select Pipeline script from SCM.
Choose Git and enter your GitHub repository URL.
In the Script Path, set the path to the Jenkinsfile (if it's in the root directory, leave it as Jenkinsfile)
in Manage Jenkins -> tools
Add JDK - JDK
Name
JDK 8
JAVA_HOME
C:\Program Files\Java\jdk1.8.0_202
Add Maven
Maven
Name
Maven 3.9.9
MAVEN_HOME
C:\Program Files\Apache\Maven\apache-maven-3.9.9

Jenkis configure:
Pipeline
Definition
Pipeline script from SCM SCM
Git
Repositories
Repository URL
https://github.com/DebaratiBiswas/CICD_mvn_java.git
Branch Specifier (blank for 'any')
main
Script Path
Jenkinsfile

##ERROR 1 ##

C:\ProgramData\Jenkins.jenkins\workspace\CICD_mvn_java_pipeline>C:\Program Files\Apache\Maven\apache-maven-3.9.9\bin\mvn.bat package 'C:\Program' is not recognized as an internal or external command, operable program or batch file.
reason: The issue you're facing occurs because the path to Maven contains spaces (i.e., C:\Program Files). Windows treats spaces in paths as separators unless the entire path is enclosed in quotes.
solution: Install the plugin:

Go to Manage Jenkins > Manage Plugins. In the Available tab, search for "Pipeline Maven Integration Plugin".
stage('Build') { steps { withMaven(maven: 'Maven3') { bat 'mvn package' }

Add Webhook for build trigger on github push

Step 1: Install the GitHub Plugin in Jenkins
Go to Manage Jenkins > Manage Plugins.
In the Available tab, search for the GitHub Plugin and install it.
Enable GitHub Webhooks Trigger
In the Build Triggers section jenkins job config, check the GitHub hook trigger for GITScm polling option.

Step 3: Set Up a GitHub Webhook
Go to your GitHub repository:
Open your repository on GitHub.
Navigate to Settings > Webhooks.
Click Add webhook.
Set up the webhook:
Payload URL: This should be your Jenkins server's URL followed by /github-webhook/ (for example: http:///github-webhook/).
Content type: Set this to application/json.
Which events would you like to trigger this webhook?: Choose Just the push event.
Click Add webhook.

Error 2

when given local host url in github webhook settings
Payload URL *
http://localhost:8080/github-webhook/
error: is not supported because it isn't reachable over the public Internet (localhost)
reason: Jenkins instance is running on localhost, which is not publicly accessible from the internet. GitHub's webhooks require a publicly accessible URL to send notifications when a repository event occurs (e.g., a push).
solution:

Step 1: Sign Up for an ngrok Account
Go to ngrok's website: https://ngrok.com/download

Visit the ngrok signup page.
Create an Account:

After signing up, check your email and verify your account using the link provided by ngrok.
Step 2: Get Your ngrok Authtoken
Log in to ngrok:

After verifying your account, log in to the ngrok dashboard. Find Your Authtoken:

In the dashboard, go to the Getting Started section.
You will find your unique Authtoken under the "Connect your account" step.
Step 3: Set Up ngrok with Your Authtoken
Copy the Authtoken:
https://dashboard.ngrok.com/get-started/your-authtoken
Copy the authtoken from the ngrok dashboard.
Run the ngrok Authtoken Command:

Open Command Prompt or PowerShell.
Run the following command to authenticate your ngrok installation:
bash
Copy code
ngrok config add-authtoken
Replace with the token you copied from the ngrok dashboard.
Step 4: Run ngrok Again
Expose Jenkins on Port 8080:

After authenticating ngrok, run the command again to expose Jenkins:
bash
Copy code
ngrok http 8080
Get the Public URL:

ngrok will now provide a public URL (e.g., http://abcd1234.ngrok.io), which you can use to access Jenkins from the internet.
Step 5: Update the GitHub Webhook with the New URL
Go to GitHub Webhook Settings:

Navigate to your repository’s Settings > Webhooks.
Update the Payload URL:

Change the Payload URL to the new public URL provided by ngrok (e.g., http://abcd1234.ngrok.io/github-webhook/).
Save the changes.

Now, your ngrok setup should be complete and functioning with the authenticated account. Let me know if you encounter any further issues!

output:
ngrok (Ctrl+C to quit) Found a bug? Let us know: https://github.com/ngrok/ngrok Session Status online Account Debarati (Plan: Free) Version 3.18.0 Region India (in) Latency 29ms Web Interface http://127.0.0.1:4040 Forwarding https://51e2-122-172-83-194.ngrok-free.app -> http://localhost:8080 Connections ttl opn rt1 rt5 p50 p90 0 0 0.00 0.00 0.00 0.00

So here public url is https://51e2-122-172-83-194.ngrok-free.app
set in github webhooks payload url as https://51e2-122-172-83-194.ngrok-free.app/github-webhook/ save and test the push triggering jenkins build