Commit 4: Basic GitHub Actions Pipeline

- Add CI workflow (.github/workflows/ci.yml)
  - Lint and Test job: code quality checks and test execution
  - Training job: validates training pipeline works
  - Runs on push to main and pull requests
  - Uploads model artifacts for 7 days

- Update documentation (docs/mlops-stages.md)
  - Document Stage 2: Automated CI Pipeline as implemented
  - Add workflow details and benefits

Author: ereztdev

.github/workflows/ci.yml

@@ -0,0 +1,111 @@
+name: CI Pipeline
+
+# This workflow runs on every push to main branch and on pull requests
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  # Job 1: Lint and Test
+  # This job validates code quality and runs tests
+  lint-and-test:
+    name: Lint and Test
+    runs-on: ubuntu-latest
+    
+    steps:
+    # Checkout the code from the repository
+    - name: Checkout code
+      uses: actions/checkout@v4
+    
+    # Set up Python environment
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.10'
+    
+    # Cache pip dependencies for faster builds
+    - name: Cache pip packages
+      uses: actions/cache@v4
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-
+    
+    # Install dependencies
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -r requirements.txt
+    
+    # Run code linting with flake8
+    # This checks for code style and potential errors
+    - name: Run linting (flake8)
+      run: |
+        flake8 src/ tests/ --count --select=E9,F63,F7,F82 --show-source --statistics
+        flake8 src/ tests/ --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+    
+    # Run tests with pytest
+    # This validates that all functionality works correctly
+    - name: Run tests
+      run: |
+        pytest tests/ -v --cov=src --cov-report=term-missing
+    
+    # Optional: Run type checking with mypy
+    # Uncomment if you want strict type checking
+    # - name: Run type checking (mypy)
+    #   run: |
+    #     mypy src/ --ignore-missing-imports
+
+  # Job 2: Training
+  # This job trains the model to ensure training pipeline works
+  train-model:
+    name: Train Model
+    runs-on: ubuntu-latest
+    
+    steps:
+    # Checkout the code
+    - name: Checkout code
+      uses: actions/checkout@v4
+    
+    # Set up Python environment
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.10'
+    
+    # Cache pip dependencies
+    - name: Cache pip packages
+      uses: actions/cache@v4
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-
+    
+    # Install dependencies
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -r requirements.txt
+    
+    # Run training script
+    # This ensures the training pipeline works and produces model artifacts
+    - name: Train model
+      run: |
+        python src/training/train.py
+    
+    # Upload model artifacts
+    # This saves the trained model files so they can be downloaded later
+    # Artifacts are stored for 90 days by default
+    - name: Upload model artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: trained-model
+        path: |
+          models/*.pkl
+        retention-days: 7
+        if-no-files-found: warn
+

docs/mlops-stages.md

@@ -30,13 +30,32 @@ docker run --rm -v $(pwd):/app mlops:latest python src/training/train.py
 
 ## Stage 2: Automated CI Pipeline
 
-**Status**: To be implemented
+**Status**: ✅ Implemented
 
-The CI pipeline will:
-- Run tests on code changes
-- Execute training jobs
-- Validate model performance
-- Store artifacts
+The CI pipeline automates quality checks and training on every code change:
+
+**GitHub Actions Workflow** (`.github/workflows/ci.yml`):
+- **Lint and Test Job**: 
+  - Runs on every push and pull request
+  - Code linting with flake8 (style and error checking)
+  - Runs all tests with pytest
+  - Code coverage reporting
+- **Training Job**:
+  - Trains the model to ensure pipeline works
+  - Validates training script executes successfully
+  - Uploads model artifacts for download
+
+**Benefits:**
+- Automatic validation on every code change
+- Catches errors before they reach production
+- Ensures training pipeline remains functional
+- Model artifacts stored for 7 days
+
+**Usage:**
+- Automatically runs on push to `main` branch
+- Automatically runs on pull requests
+- View results in GitHub Actions tab
+- Download artifacts from workflow runs
 
 ## Stage 3: Artifact Handling