Lab 1 Report

Lab 1 Report

Successful Run

Link: Successful CI/CD job run

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.gitlab-ci.yml Structure

Image:
Uses a JDK 25 Docker image for Maven builds.

Variables:
Defines Maven flags and a local .m2 cache for faster builds.

Cache:
Reuses dependencies between stages using maven-deps key.

Stages:
build → package → run

Jobs:

maven-build:
  stage: build
  script:
    - ./mvnw clean package
  artifacts:
    paths:
      - target/
  cache:
    key: maven-deps
    paths:
      - .m2/repository

maven-container-image-generation:
  stage: package
  script:
    - echo "Building container image..."

run-game:
  stage: run
  script:
    - java -jar target/game.jar

Problems & Solutions:

• Problem: WARNING: .m2/repository: no matching files.
• Cause: Artifact path was not relative to the working directory.
• Fix: In maven-build, added mkdir -p .m2/repository to create the missing directory.

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Questions

1. What is ./mvnw and its advantage over mvn?

./mvnw is the Maven Wrapper, a script that ensures a specific Maven version is downloaded and used automatically.
Advantage: it guarantees build consistency across environments without requiring Maven to be preinstalled.

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2. GitLab Cache vs Artifacts

Feature	Purpose	Example	Lifetime
Cache	Reusable data between jobs (e.g., dependencies)	.m2/repository	Reused across pipelines
Artifacts	Job outputs passed between stages	target/	Available until expiration

Choice:

• Maven dependencies → Cache (speeds up builds, reused across stages)
• Build files (target/) → Artifacts (passed to packaging stage, short-lived)

Trade-offs:

• Cache improves speed but risks stale data if dependencies change.
• Artifacts ensure correct, isolated results but increase storage use and job time.

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3. 25-jre vs 25-jdk Images

Image	Includes	Use Case	Pros	Cons
JDK (25-jdk)	Compilers & build tools	Building code	Versatile	Larger size
JRE (25-jre)	Runtime only	Running apps	Lightweight	Cannot build

Reasoning:

• Using 25-jdk for both:
  • Simpler setup (single image)
  • Heavier runtime, slower startup, larger attack surface
• Using 25-jre for both:
  • Build jobs would fail (no compiler or Maven tools)
  • Slightly smaller image size, but not functional for building