TaskFlow App

A cloud-native task management application built with Flask and designed for Kubernetes/OpenShift deployment.

Overview

TaskFlow is a RESTful API service for managing tasks. It supports both in-memory storage (development) and PostgreSQL database (production), making it suitable for learning container orchestration and cloud deployment patterns.

Architecture

• Backend: Flask (Python) REST API
• Container Runtime: Docker
• Orchestration: Kubernetes/OpenShift
• Database: PostgreSQL (optional, enabled with USE_DATABASE=true)
• Storage: In-memory (default) or PostgreSQL

Project Structure

taskflow-app/
├── app/
│   ├── backend/
│   │   ├── app.py              # Flask application
│   │   ├── Dockerfile          # Container image definition
│   │   └── requirements.txt    # Python dependencies
│   └── database/
│       └── init.sql            # Database schema initialization
├── k8s/
│   ├── week1-kubernetes/       # Basic Kubernetes deployment
│   ├── week2-s2i/              # Source-to-Image build configs
│   └── week3-database/         # PostgreSQL StatefulSet & integration
│       ├── postgres-statefulset.yaml
│       ├── database-secret.yaml
│       ├── configmap-with-db.yaml
│       └── deployment-with-db.yaml
├── ansible/                    # Week 4: Ansible automation
│   ├── ansible.cfg
│   ├── env.sh                  # Environment configuration
│   ├── inventory/
│   │   └── openshift.yml
│   ├── roles/
│   │   ├── taskflow-backend/
│   │   └── taskflow-database/
│   └── playbooks/
│       ├── 01-simple-namespace.yml
│       ├── deploy-full-stack.yml
│       └── day2-operations.yml
├── docs/
│   ├── week3-precheck.sh       # Week 3 prerequisites check
│   ├── verify-week3.sh         # Week 3 verification script
│   └── week4-precheck.sh       # Week 4 prerequisites check
├── get-db-pod.sh               # Database pod helper script
└── README.md

API Endpoints

• GET / - Application info
• GET /api - API information with database status
• GET /health - Health check endpoint
• GET /api/tasks - List all tasks
• POST /api/tasks - Create a new task
• PUT /api/tasks/<id> - Update a task
• DELETE /api/tasks/<id> - Delete a task

Local Development

Prerequisites

• Python 3.13+
• Docker (for containerization)
• Kubernetes/OpenShift cluster (for deployment)

Run Locally

cd app/backend
python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate
pip install -r requirements.txt
python app.py

The API will be available at http://localhost:8080

Test the API

# Get all tasks
curl http://localhost:8080/api/tasks

# Create a task
curl -X POST http://localhost:8080/api/tasks \
  -H "Content-Type: application/json" \
  -d '{"title":"New Task"}'

# Update a task
curl -X PUT http://localhost:8080/api/tasks/1 \
  -H "Content-Type: application/json" \
  -d '{"completed":true}'

# Delete a task
curl -X DELETE http://localhost:8080/api/tasks/1

Container Build

cd app/backend
docker build -t taskflow-backend:v1.0 .
docker run -p 8080:8080 taskflow-backend:v1.0

Deployment

Ansible Deployment (Current - Week 4)

# Prerequisites check
./docs/week4-precheck.sh

# Setup Ansible environment
cd ansible
source env.sh

# Deploy full stack (database + backend)
ansible-playbook playbooks/deploy-full-stack.yml

# Check health and status
ansible-playbook playbooks/day2-operations.yml

# Verify deployment
BACKEND=$(oc get route taskflow-backend -n happyotter-dev -o jsonpath='{.spec.host}')
curl https://$BACKEND/health

OpenShift Deployment (Week 3 - Manual)

# Prerequisites check
./docs/week3-precheck.sh

# Deploy PostgreSQL StatefulSet
oc apply -f k8s/week3-database/postgres-statefulset.yaml

# Create database secret
oc apply -f k8s/week3-database/database-secret.yaml

# Update ConfigMap and Deployment with database integration
oc apply -f k8s/week3-database/configmap-with-db.yaml
oc apply -f k8s/week3-database/deployment-with-db.yaml

# Initialize database
DB_POD=$(./get-db-pod.sh happyotter-dev)
oc cp app/database/init.sql $DB_POD:/tmp/init.sql -n happyotter-dev
oc exec -it $DB_POD -n happyotter-dev -- psql -U taskflowuser -d taskflowdb -f /tmp/init.sql

# Verify deployment
./docs/verify-week3.sh

Kubernetes Deployment (Week 1)

# Apply all manifests
kubectl apply -f k8s/week1-kubernetes/

# Check deployment status
kubectl get all -n happyotter-dev

# View logs
kubectl logs -n happyotter-dev deployment/taskflow-backend

Access the Application

# OpenShift Route (automatic)
ROUTE=$(oc get route taskflow-backend -n happyotter-dev -o jsonpath='{.spec.host}')
curl https://$ROUTE/health

# Kubernetes Port Forward
kubectl port-forward -n happyotter-dev service/taskflow-backend 8080:8080

Configuration

The application uses environment variables configured via ConfigMap:

• APP_VERSION - Application version (default: "1.0")
• ENVIRONMENT - Environment name (default: "development")
• USE_DATABASE - Enable PostgreSQL (default: "false")
• DB_HOST - Database host (when USE_DATABASE=true)
• DB_NAME - Database name
• DB_USER - Database user
• DB_PASSWORD - Database password (use Secrets in production)
• DB_PORT - Database port (default: "5432")

Features

Week 1: Kubernetes Basics ✓

• Containerized Flask application
• Kubernetes manifests (Namespace, ConfigMap, Deployment, Service)
• RESTful API with CRUD operations
• Health check endpoint
• Resource limits and requests
• Liveness and readiness probes
• Security context configuration

Week 2: OpenShift & CI/CD ✓

• OpenShift deployment
• Source-to-Image (S2I) builds
• BuildConfig and ImageStream
• OpenShift Routes for external access
• GitHub webhook integration
• Automated CI/CD pipeline

Week 3: Database Integration ✓

• PostgreSQL StatefulSet deployment
• Persistent Volume Claims (PVC)
• Database secrets management
• Application-database connectivity
• Database initialization scripts
• Connection pooling
• Health checks with database status

Week 4: Ansible Automation ✓

• Ansible environment setup
• Ansible roles (backend, database)
• Full stack deployment playbook
• Day 2 operations (health checks)
• Idempotent resource management
• OpenShift security context compliance
• Automated route creation with TLS

Upcoming Features

• Frontend application
• Monitoring and logging
• Advanced security features
• GitOps with ArgoCD

Deployment Details

Application

• Namespace: happyotter-dev
• Backend Replicas: 2
• Image: quay.io/happyotter/taskflow-backend (built via S2I)
• Port: 8080
• Resource Requests: 100m CPU, 128Mi memory
• Resource Limits: 500m CPU, 512Mi memory

Database

• Type: PostgreSQL 15 (Alpine)
• Deployment: StatefulSet (1 replica)
• Storage: 1Gi Persistent Volume (gp3 storage class)
• Service: Headless service (ClusterIP: None)
• Port: 5432
• Resource Requests: 100m CPU, 256Mi memory
• Resource Limits: 500m CPU, 512Mi memory

URLs

• API: https://taskflow-backend-happyotter-dev.apps.rm3.7wse.p1.openshiftapps.com
• Health: https://taskflow-backend-happyotter-dev.apps.rm3.7wse.p1.openshiftapps.com/health
• Tasks API: https://taskflow-backend-happyotter-dev.apps.rm3.7wse.p1.openshiftapps.com/api/tasks

License

This project is for educational purposes.