Chapter 22: Jenkins Language Projects — Java to Python

22.6 PHP — start to end

By Ravindra Bagale · Last updated: 25 October 2026

Why: the problem

Think of a Zomato restaurant partner portal, or the many WordPress and Laravel sites that Indian agencies build. They are written in PHP. PHP code does not compile to a jar, so learners think there is nothing to build. But there is: Composer installs the libraries into a vendor folder, PHPUnit runs the tests, and php -l checks every file for syntax errors. A broken comma in one file can take a whole site down, so CI must catch it before the copy to the server. In this lesson you build the badge rule in PHP with Composer and PHPUnit, run a lint over all files, and make Jenkins test, package a zip, and copy it to a lab live folder.

What we will build

You will create composer.json, a Badge class and a PHPUnit test, run lint and tests locally, write a Jenkinsfile using the composer Docker image, package a release zip without dev libraries, and see red for a syntax error.

What: every term in plain English

• PHP — A language for web pages and APIs, used by WordPress and Laravel.
• Composer — The PHP library manager. Reads composer.json.
• composer.lock — Exact library versions. Commit it so CI installs the same.
• vendor/ — Folder where Composer puts libraries. Do not commit it.
• PHPUnit — The PHP test tool.
• php -l — Lint: checks a file for syntax errors.
• PSR-4 autoload — A rule that maps a namespace to a folder.
• --no-dev — Skip test libraries for production.

How: step by step

1. Make the folder

   mkdir -p ~/devops-lab/ch22/badge-php/src ~/devops-lab/ch22/badge-php/tests && cd ~/devops-lab/ch22/badge-php
   

   What it does: Project root.

   Output

   (no output)
   

2. Add the files

   composer.json, src/Badge.php, tests/BadgeTest.php, phpunit.xml from Example 1
   

   What it does: Copy exactly.

   Output

   (no output)
   

3. Add the PHP open tag

   for f in src/Badge.php tests/BadgeTest.php; do printf "\x3c?php\n" | cat - "$f" > "$f.tmp" && mv "$f.tmp" "$f"; done; head -1 src/Badge.php
   

   What it does: Every PHP file must start with the open tag. printf writes it for us.

   Output

   (the PHP open tag)
   

4. Install

   composer install
   

   What it does: Creates vendor and composer.lock.

   Output

   Generating autoload files
   

5. Lint

   find src tests -name "*.php" -print0 | xargs -0 -n1 php -l
   

   What it does: Syntax check.

   Output

   No syntax errors detected in src/Badge.php
   No syntax errors detected in tests/BadgeTest.php
   

6. Test

   vendor/bin/phpunit
   

   What it does: Run tests.

   Output

   OK (3 tests, 3 assertions)
   

7. Run once

   php -r "require \"vendor/autoload.php\"; echo App\\Badge::level(120), PHP_EOL;"
   

   What it does: The rule works.

   Output

   gold
   

Example 1: The PHP project

Stack. PHP 8.3, Composer, PHPUnit 11

Goal. The PHP project. Line 1 of each .php file is the PHP open tag added in step 3.

composer.json

{
  "name": "example/badge-php",
  "require": { "php": ">=8.2" },
  "require-dev": { "phpunit/phpunit": "^11.0" },
  "autoload": { "psr-4": { "App\\": "src/" } }
}

src/Badge.php

namespace App;

final class Badge
{
    public static function level(int $points): string
    {
        if ($points >= 100) { return 'gold'; }
        if ($points >= 50)  { return 'silver'; }
        return 'bronze';
    }
}

tests/BadgeTest.php

use App\Badge;
use PHPUnit\Framework\TestCase;

final class BadgeTest extends TestCase
{
    public function testGold(): void   { $this->assertSame('gold', Badge::level(100)); }
    public function testSilver(): void { $this->assertSame('silver', Badge::level(50)); }
    public function testBronze(): void { $this->assertSame('bronze', Badge::level(0)); }
}

phpunit.xml

<phpunit bootstrap="vendor/autoload.php" colors="false">
  <testsuites>
    <testsuite name="unit"><directory>tests</directory></testsuite>
  </testsuites>
</phpunit>

What each line does

• require-dev — PHPUnit only for development and CI.
• psr-4 App to src/ — App\Badge is loaded from src/Badge.php.
• final class — Cannot be extended; simple and safe.
• assertSame — Value and type must match.
• bootstrap autoload — Tests can find App classes.

Green output

PHPUnit 11.4.0 by Sebastian Bergmann and contributors.

...                                                                 3 / 3 (100%)

OK (3 tests, 3 assertions)

Expected result. Three dots mean three passing tests.

Example 2: Jenkinsfile with lint, tests and a release zip

Stack. Jenkins, Docker, PHP

Goal. Jenkinsfile with lint, tests and a release zip.

Jenkinsfile

pipeline {
  agent { docker { image 'composer:2'; args '-e COMPOSER_HOME=/tmp/composer' } }
  options { timestamps() }
  stages {
    stage('Checkout') { steps { checkout scm } }
    stage('Install')  { steps { sh 'composer install --no-interaction --prefer-dist' } }
    stage('Lint')     { steps { sh 'find src tests -name "*.php" -print0 | xargs -0 -n1 php -l' } }
    stage('Test')     { steps { sh 'vendor/bin/phpunit --log-junit junit.xml' } }
    stage('Package') {
      steps {
        sh 'rm -rf vendor && composer install --no-dev --no-interaction --optimize-autoloader'
        sh 'mkdir -p dist && zip -qr dist/badge-php-${BUILD_NUMBER}.zip src vendor composer.json'
      }
    }
    stage('Live') { steps { sh 'mkdir -p "$HOME/lab-live/badge-php" && cp dist/*.zip "$HOME/lab-live/badge-php/"' } }
  }
  post {
    always  { junit 'junit.xml' }
    success { archiveArtifacts 'dist/*.zip' }
  }
}

What each line does

• composer:2 image — Has PHP and Composer.
• --prefer-dist — Download zips, faster than git clones.
• Lint stage — Catch syntax errors in every file.
• --log-junit — PHPUnit writes JUnit XML for Jenkins.
• --no-dev — Production zip without PHPUnit.
• --optimize-autoloader — Faster class loading in production.

Green output

[Pipeline] stage (Lint)
No syntax errors detected in src/Badge.php
[Pipeline] stage (Test)
OK (3 tests, 3 assertions)
[Pipeline] stage (Package)
Archiving artifacts
Finished: SUCCESS

Expected result. A tested zip ready to unpack on the web server.

Example 3: A syntax error caught by lint

Stack. PHP

Goal. A syntax error caught by lint.

break.sh

sed -i "s/return 'bronze';/return 'bronze'/" src/Badge.php
php -l src/Badge.php

What each line does

• Missing semicolon — A one-character mistake.
• php -l — Finds it without running the site.

Green output

PHP Parse error:  syntax error, unexpected token "}" in src/Badge.php on line 10
Errors parsing src/Badge.php
script returned exit code 255

Expected result. Lint stage red. Fix line 10, push again. Without lint, this would be a white page on the live site.

Example 4: Run the PHP app behind the built-in server for a smoke test

Stack. PHP

Goal. Run the PHP app behind the built-in server for a smoke test.

public/index.php body

require __DIR__ . '/../vendor/autoload.php';
header('Content-Type: application/json');
$p = (int)($_GET['points'] ?? 0);
echo json_encode(['points' => $p, 'level' => App\Badge::level($p)]);

smoke.sh

php -S 127.0.0.1:18090 -t public > php.log 2>&1 &
sleep 1
curl -fs "127.0.0.1:18090/?points=60"
kill %1

What each line does

• php -S — Built-in dev server, fine for CI smoke tests.
• -t public — Serve from public/.
• json_encode — Return JSON.

Green output

{"points":60,"level":"silver"}

Expected result. The page answers before you copy anything to a real server.

Verify: did it work?

1. vendor ignored

   grep vendor .gitignore
   

   What it does: Not committed.

   Output

   vendor/
   

2. Lock committed

   git ls-files composer.lock
   

   What it does: Same versions in CI.

   Output

   composer.lock
   

3. Zip content

   unzip -l dist/*.zip | tail -1
   

   What it does: Has files.

   Output

   412  37 files
   

When it is red 1

composer: command not found

Cause. No Composer on the agent.

Fix, step by step

1. Use the composer:2 Docker agent.

When it is red 2

Your lock file does not contain a compatible set of packages

Cause. composer.lock made with a different PHP version.

Fix, step by step

1. Run composer update locally with the same PHP version as CI, commit the lock.

When it is red 3

Class "App\\Badge" not found

Cause. Autoload not built or wrong namespace path.

Fix, step by step

1. Check psr-4 in composer.json.
2. Run composer dump-autoload.

When it is red 4

PHP Parse error: syntax error, unexpected token

Cause. Typo in a PHP file.

Fix, step by step

1. Open the file at the line number.
2. Fix and run php -l again.

Cleanup

1. Clean

   rm -rf vendor dist junit.xml
   

   What it does: Fresh folder.

   Output

   (no output)
   

Practice tasks

Homework: try at home

Recap

• PHP has a build too: install, lint, test, package.
• Commit composer.lock, not vendor.
• php -l catches typos.
• Use --no-dev for production.
• Publish JUnit XML.

FAQ

Why does PHP need CI if it does not compile?

Tests and lint still catch bugs before users see them.

Laravel or WordPress?

Same stages; Laravel adds php artisan test.

Can I deploy with rsync instead of zip?

Yes. The zip is easy to archive and roll back.

Which PHP version in CI?

The same as production. Pin it with the image tag.

Where do .env secrets go?

On the server or in Jenkins credentials, never in Git.

Why is the open tag added with printf?

Only for this page; in your editor just type it as line 1.

Interview questions

1. How do you build a PHP project in CI?

   composer install, lint, phpunit, then composer install --no-dev and package.

2. Why commit composer.lock?

   Reproducible installs.

3. How do you catch syntax errors early?

   php -l over all files.

4. What is PSR-4?

   Namespace to folder autoload standard.

5. How do you show PHPUnit results in Jenkins?

   --log-junit and the junit step.

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