Lab03

.github/workflows/python-ci.yml

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+name: Python CI - DevOps Info Service
+
+on:
+  push:
+    branches: [ "**" ]
+    tags:
+      - "v*.*.*"
+    paths:
+      - "app_python/**"
+      - ".github/workflows/python-ci.yml"
+
+  pull_request:
+    branches: [ "main" ]
+    paths:
+      - "app_python/**"
+
+jobs:
+  test:
+    name: Lint & Test
+    runs-on: ubuntu-latest
+
+    defaults:
+      run:
+        working-directory: app_python
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Python 3.11
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+          cache: "pip"
+          cache-dependency-path: |
+            app_python/requirements.txt
+            app_python/requirements-dev.txt
+
+      - name: Install dependencies
+        run: |
+          pip install -r requirements.txt
+          pip install -r requirements-dev.txt
+
+      - name: Run linter (ruff)
+        run: |
+          pip install ruff
+          ruff check .
+
+      - name: Run tests with coverage
+        run: |
+          pytest --cov=. --cov-report=term-missing --cov-fail-under=60
+
+      - name: Install Bandit
+        run: pip install bandit
+
+      - name: Run Bandit security scan
+        run: bandit -r . -ll -s B101,B104
+
+  docker:
+    name: Build & Push Docker Image
+    needs: test
+    if: startsWith(github.ref, 'refs/tags/')
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Extract version
+        id: vars
+        run: echo "VERSION=${GITHUB_REF#refs/tags/v}" >> $GITHUB_OUTPUT
+
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build and push image
+        uses: docker/build-push-action@v5
+        with:
+          context: ./app_python
+          push: true
+          tags: |
+            ${{ secrets.DOCKERHUB_USERNAME }}/devops-info-service:${{ steps.vars.outputs.VERSION }}
+            ${{ secrets.DOCKERHUB_USERNAME }}/devops-info-service:latest

README.md

@@ -1,3 +1,6 @@
+![CI](https://github.com/essence-666/DevOps-Core-Course/actions/workflows/python-ci.yml/badge.svg)
+
+
 # DevOps Engineering: Core Practices
 
 [![Labs](https://img.shields.io/badge/Labs-18-blue)](#labs)

app_go/Dockerfile

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+# -------- Build stage --------
+FROM golang:1.25-alpine AS builder
+
+WORKDIR /app
+COPY go.mod ./
+RUN go mod download
+
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o app
+
+# -------- Runtime stage --------
+FROM alpine:latest
+
+RUN addgroup -S appgroup && adduser -S appuser -G appgroup
+
+WORKDIR /app
+COPY --from=builder /app/app .
+
+RUN chown appuser:appgroup /app/app
+
+USER appuser
+
+EXPOSE 5000
+CMD ["./app"]

app_go/README.md

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+# DevOps Info Service (Go)
+
+## Overview
+
+DevOps Info Service is a Go-based web application that provides detailed
+information about the service itself, system environment, runtime status, and
+incoming HTTP requests.
+
+The application is implemented in a single source file for simplicity.
+
+---
+
+## Prerequisites
+
+- Go 1.22+
+- Docker (optional)
+
+---
+
+## Running Locally
+
+```bash
+go run main.go
+````
+
+### Custom Configuration
+
+```bash
+PORT=8080 go run main.go
+HOST=127.0.0.1 PORT=3000 go run main.go
+```
+
+---
+
+## API Endpoints
+
+| Method | Path    | Description                    |
+| ------ | ------- | ------------------------------ |
+| GET    | /       | Service and system information |
+| GET    | /health | Health check                   |
+
+---
+
+## Configuration
+
+| Variable | Default | Description      |
+| -------- | ------- | ---------------- |
+| HOST     | 0.0.0.0 | Bind address     |
+| PORT     | 5000    | Application port |
+
+---
+
+## Docker Build (Multi-Stage)
+
+```bash
+docker build -t devops-info-go .
+docker run -p 5000:5000 devops-info-go
+```

app_go/docs/LAB01.md

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+# Lab 01 – DevOps Info Service (Go)
+
+## Framework Selection
+
+### Chosen Language and Framework: Go (net/http)
+
+The Go programming language with the standard `net/http` package was chosen
+for this laboratory work. Go is widely used in DevOps and cloud-native
+environments due to its performance, static compilation, simplicity, and
+excellent support for concurrent workloads.
+
+Using the standard library avoids unnecessary dependencies and keeps the
+service lightweight and predictable.
+
+### Comparison with Alternatives
+
+| Option | Pros | Cons | Reason Not Chosen |
+|------|------|------|-------------------|
+| Go (net/http) | Fast, static binary, no dependencies | Less abstraction | Chosen |
+| Gin | Simple routing, middleware | External dependency | Not required |
+| Echo | High performance | External dependency | Overkill |
+| Python (FastAPI) | Rapid development, async | Interpreted, slower startup | Language diversity |
+
+---
+
+## Best Practices Applied
+
+### 1. Minimal Dependency Usage
+
+Only the Go standard library is used.
+
+**Example:**
+```go
+import "net/http"
+````
+
+**Importance:**
+Reduces attack surface, simplifies builds, and improves reliability.
+
+---
+
+### 2. Single Responsibility Structure
+
+Although the application is implemented in a single file, logical separation
+is maintained through clearly defined functions.
+
+**Example:**
+
+```go
+func healthHandler(w http.ResponseWriter, r *http.Request)
+```
+
+**Importance:**
+Keeps the code readable while remaining suitable for small services.
+
+---
+
+### 3. Environment-Based Configuration
+
+Runtime configuration is handled via environment variables.
+
+**Example:**
+
+```go
+port := os.Getenv("PORT")
+```
+
+**Importance:**
+Allows flexible deployment across environments without code changes.
+
+---
+
+### 4. Structured JSON Responses
+
+All responses are returned in structured JSON format.
+
+**Example:**
+
+```go
+json.NewEncoder(w).Encode(response)
+```
+
+**Importance:**
+Ensures API consistency and ease of integration.
+
+---
+
+### 5. Health Check Endpoint
+
+A dedicated health check endpoint is implemented.
+
+**Example:**
+
+```go
+http.HandleFunc("/health", healthHandler)
+```
+
+**Importance:**
+Required for monitoring systems and container orchestration platforms.
+
+---
+
+## API Documentation
+
+### GET /
+
+**Description:**
+Returns service metadata, system information, runtime statistics, and request
+details.
+
+**Example Response:**
+
+```json
+{
+  "service": {
+    "name": "devops-info-service",
+    "language": "go"
+  }
+}
+```
+
+---
+
+### GET /health
+
+**Description:**
+Returns application health status.
+
+**Example Response:**
+
+```json
+{
+  "status": "healthy"
+}
+```
+
+---
+
+### Testing Commands
+
+```bash
+curl http://localhost:5000/
+curl http://localhost:5000/health
+```
+
+---
+
+## Testing Evidence
+
+The following screenshots are provided:
+
+* Main endpoint (`/`) showing full JSON response
+* Health check endpoint (`/health`)
+* Pretty-printed JSON output in terminal
+
+---
+
+## Challenges & Solutions
+
+### Problem 1: Balancing simplicity and structure
+
+**Issue:**
+Splitting the application into multiple files was unnecessary for the scope of
+the laboratory work.
+
+**Solution:**
+Implemented all logic in a single file while preserving logical separation via
+functions.
+
+---
+
+### Problem 2: Container image size optimization
+
+**Issue:**
+Default Go images produce relatively large containers.
+
+**Solution:**
+Implemented a multi-stage Docker build to produce a minimal runtime image.
+
+````