feat: Base application for devops introduction

Author: Jens van der Wateren

.github/workflows/ci.yml

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+name: CI Pipeline
+
+on:
+  push:
+    branches: [ main, develop ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up JDK 17
+      uses: actions/setup-java@v4
+      with:
+        java-version: '17'
+        distribution: 'temurin'
+
+    - name: Cache Maven dependencies
+      uses: actions/cache@v3
+      with:
+        path: ~/.m2
+        key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
+        restore-keys: ${{ runner.os }}-m2
+
+    - name: Run tests
+      run: ./mvnw clean test
+
+    - name: Run linting (Checkstyle)
+      run: ./mvnw checkstyle:check
+
+    - name: Run static analysis (SpotBugs)
+      run: ./mvnw spotbugs:check
+
+    - name: Build application
+      run: ./mvnw clean package -DskipTests
+
+  docker:
+    runs-on: ubuntu-latest
+    needs: test
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Build Docker image
+      run: docker build -t devops-training:latest .
+
+    - name: Test Docker image
+      run: |
+        docker run -d -p 8080:8080 --name test-app devops-training:latest
+        sleep 30
+        curl -f http://localhost:8080/api/health || exit 1
+        docker stop test-app
+        docker rm test-app

.idea/github-actions.iml

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+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.5/apache-maven-3.9.5-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar

.idea/misc.xml

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+# Use Maven image with OpenJDK 17 as base image
+FROM maven:latest AS build
+
+# Set working directory
+WORKDIR /workspace/app
+
+# Copy pom.xml and checkstyle config
+COPY pom.xml .
+COPY checkstyle.xml .
+RUN mvn dependency:go-offline -B
+
+# Copy source code
+COPY src src
+
+# Build application
+RUN mvn package -DskipTests
+RUN mkdir -p target/dependency && (cd target/dependency; jar -xf ../*.jar)
+
+# Production stage
+FROM openjdk:17-jdk-slim
+
+# Create non-root user for security
+RUN groupadd -r spring && useradd -r -g spring spring
+
+# Set working directory
+WORKDIR /app
+
+# Copy built application from build stage
+ARG DEPENDENCY=/workspace/app/target/dependency
+COPY --from=build ${DEPENDENCY}/BOOT-INF/lib /app/lib
+COPY --from=build ${DEPENDENCY}/META-INF /app/META-INF
+COPY --from=build ${DEPENDENCY}/BOOT-INF/classes /app
+
+# Change ownership to spring user
+RUN chown -R spring:spring /app
+USER spring
+
+# Expose port
+EXPOSE 8080
+
+# Run application
+ENTRYPOINT ["java","-cp","app:app/lib/*","com.example.devopstraining.DevopsTrainingApplication"]

.idea/modules.xml

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+# DevOps Training Project
+
+A Spring Boot application designed for DevOps training with linting, testing, and CI/CD pipeline examples.
+
+## Project Structure
+
+- **Spring Boot 3.2.0** with Java 17
+- **REST API** with simple endpoints
+- **Unit Tests** using Spring Boot Test
+- **Linting** with Checkstyle and SpotBugs
+- **Docker** containerization
+- **GitHub Actions** CI pipeline
+
+## Quick Start
+
+### Local Development
+```bash
+./mvnw spring-boot:run
+```
+
+### Docker
+```bash
+# Build and run with Docker Compose
+docker-compose up --build
+
+# Or build and run manually
+docker build -t devops-training .
+docker run -p 8080:8080 devops-training
+```
+
+### Testing
+```bash
+./mvnw test
+```
+
+### Linting
+```bash
+./mvnw checkstyle:check
+./mvnw spotbugs:check
+```
+
+## API Endpoints
+
+- `GET /api/hello` - Returns a hello message
+- `GET /api/hello/{name}` - Returns a personalized hello message
+- `GET /api/health` - Health check endpoint
+
+## Training Goals
+
+This project serves as a starting point for DevOps training. Students should:
+
+1. **Current State**: The project builds, tests pass, and basic CI runs
+2. **Add More Pipeline Steps**: Extend the GitHub Actions workflow with:
+   - Security scanning
+   - Code coverage reporting
+   - Docker image scanning
+   - Deployment stages
+   - Integration testing
+   - Performance testing
+
+## GitHub Actions Workflow
+
+The current `.github/workflows/ci.yml` includes:
+- Running tests
+- Code linting (Checkstyle & SpotBugs)
+- Building the application
+- Docker image build and basic testing
+
+### Training Exercises
+
+Students can extend the pipeline by adding:
+- Code coverage with JaCoCo
+- OWASP dependency check
+- SonarQube analysis
+- Multi-environment deployments
+- Slack/email notifications
+- Automated releases
+
+## Known Issues
+
+The current code has intentional Checkstyle violations to demonstrate linting in action. This is perfect for training scenarios where students learn to:
+1. Identify code quality issues
+2. Fix linting violations
+3. Understand the importance of code standards

.idea/workspace.xml

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+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+        "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+        "https://checkstyle.org/dtds/configuration_1_3.dtd">
+
+<module name="Checker">
+    <property name="charset" value="UTF-8"/>
+    <property name="severity" value="warning"/>
+    <property name="fileExtensions" value="java, properties, xml"/>
+
+    <!-- Checks for whitespace -->
+    <module name="FileTabCharacter">
+        <property name="eachLine" value="true"/>
+    </module>
+
+    <!-- Checks for Size Violations -->
+    <module name="LineLength">
+        <property name="max" value="120"/>
+    </module>
+
+    <module name="TreeWalker">
+        <!-- Checks for Naming Conventions -->
+        <module name="ConstantName"/>
+        <module name="LocalFinalVariableName"/>
+        <module name="LocalVariableName"/>
+        <module name="MemberName"/>
+        <module name="MethodName"/>
+        <module name="PackageName"/>
+        <module name="ParameterName"/>
+        <module name="StaticVariableName"/>
+        <module name="TypeName"/>
+
+        <!-- Checks for imports -->
+        <module name="AvoidStarImport"/>
+        <module name="IllegalImport"/>
+        <module name="RedundantImport"/>
+        <module name="UnusedImports"/>
+
+        <!-- Checks for Size Violations -->
+        <module name="MethodLength"/>
+        <module name="ParameterNumber"/>
+
+        <!-- Checks for whitespace -->
+        <module name="EmptyForIteratorPad"/>
+        <module name="GenericWhitespace"/>
+        <module name="MethodParamPad"/>
+        <module name="NoWhitespaceAfter"/>
+        <module name="NoWhitespaceBefore"/>
+        <module name="OperatorWrap"/>
+        <module name="ParenPad"/>
+        <module name="TypecastParenPad"/>
+        <module name="WhitespaceAfter"/>
+        <module name="WhitespaceAround"/>
+
+        <!-- Modifier Checks -->
+        <module name="ModifierOrder"/>
+        <module name="RedundantModifier"/>
+
+        <!-- Checks for blocks -->
+        <module name="AvoidNestedBlocks"/>
+        <module name="EmptyBlock"/>
+        <module name="LeftCurly"/>
+        <module name="NeedBraces"/>
+        <module name="RightCurly"/>
+
+        <!-- Checks for common coding problems -->
+        <module name="EmptyStatement"/>
+        <module name="EqualsHashCode"/>
+        <module name="HiddenField">
+            <property name="ignoreSetter" value="true"/>
+            <property name="ignoreConstructorParameter" value="true"/>
+        </module>
+        <module name="IllegalInstantiation"/>
+        <module name="InnerAssignment"/>
+        <module name="MissingSwitchDefault"/>
+        <module name="SimplifyBooleanExpression"/>
+        <module name="SimplifyBooleanReturn"/>
+
+        <!-- Checks for class design -->
+        <module name="DesignForExtension"/>
+        <module name="FinalClass"/>
+        <module name="HideUtilityClassConstructor"/>
+        <module name="InterfaceIsType"/>
+        <module name="VisibilityModifier"/>
+
+        <!-- Miscellaneous other checks -->
+        <module name="ArrayTypeStyle"/>
+        <module name="FinalParameters"/>
+        <module name="TodoComment"/>
+        <module name="UpperEll"/>
+    </module>
+</module>

.mvn/wrapper/maven-wrapper.properties

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+version: '3.8'
+
+services:
+  app:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    ports:
+      - "8080:8080"
+    environment:
+      - SPRING_PROFILES_ACTIVE=docker
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:8080/api/health"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 40s
+    restart: unless-stopped