📝 Task Manager CRUD API

A simple full-stack task management application built with Go, PostgreSQL, and Docker. Users can securely manage personal to-do lists with authentication and a clean web interface.

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🚀 Features

• 🔐 User authentication (login/logout)
• ✅ Create, read, update, delete (CRUD) tasks
• 📌 Mark tasks as complete/incomplete
• ⚡ Fast backend using Go
• 🐘 PostgreSQL database with indexing
• 🐳 Dockerized setup for easy deployment
• 🌐 Simple frontend with HTML + Tailwind CSS
• 🛠 Infrastructure automation using Terraform & Ansible
• 💻 Monitoring Logs, System and Uptime

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🏗️ Project Structure

task-manager/
.
├── ansible
│   ├── deploy.yml
│   ├── inventory.yml
│   ├── node_expoter.yml
│   └── update-install.yml
├── cmd
│   └── server
├── docker-compose.yml
├── Dockerfile
├── docs
│   ├── ansible-task.log
│   ├── images
│   ├── nginx-with-ha.log
│   └── terraform-task.log
├── go.mod
├── go.sum
├── internal
│   ├── config
│   ├── handlers
│   ├── middleware
│   ├── models
│   ├── repository
│   └── services
├── LICENSE
├── migrations
│   └── init.sql
├── monitoring
│   ├── alertmanager
│   ├── alloy
│   ├── blackbox-exporter
│   ├── docker-compose.yml
│   ├── grafana-storage
│   ├── loki
│   ├── prometheus
│   └── webhook_receiver
├── nginx.conf
├── README.md
├── terraform
│   ├── main.tf
│   ├── terraform.tf
│   ├── terraform.tfstate
│   ├── terraform.tfstate.backup
│   ├── vagrant
│   └── variable.tf
└── web
    └── templates

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⚙️ Technologies Used

• Backend: Go 1.25
• Database: PostgreSQL 17
• Frontend: HTML + Tailwind CSS
• Authentication: bcrypt password hashing
• Containerization: Docker & Docker Compose
• Infrastructure: Terraform + Ansible
• Monitoring: Prometheus, Grafana, Loki, Alloy, Alertmanager, blackbox-exporter

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🔌 API Endpoints

Method	Endpoint	Description
GET	/	Login page
POST	/login	Authenticate user
GET	/logout	Logout user
GET	/dashboard	View tasks
POST	/task/create	Create task
POST	/task/update	Update task
GET	/task/toggle	Toggle completion
GET	/task/delete	Delete task

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🚀 Quick Start

Prerequisites

• Docker & Docker Compose
• Go 1.25 (for local development)
• PostgreSQL 17 (or use Docker)

Using Docker (Recommended)

# Clone and navigate
cd crud-api

# Start the application
docker-compose up -d

# Application runs on http://localhost:8080

Local Development

# Install dependencies
go mod download

# Set environment variables
export DB_USER=postgres
export DB_PASS=password
export DB_HOST=localhost
export DB_PORT=5432
export DB_NAME=task_manager

# Run migrations
psql -U postgres -d task_manager -f migrations/init.sql

# Start server
go run cmd/server/main.go

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📋 Environment Variables

DB_USER=postgres
DB_PASS=your_password
DB_HOST=localhost
DB_PORT=5432
DB_NAME=task_manager
SERVER_PORT=8080

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📊 Monitoring

Monitoring stack includes:

• Prometheus - Metrics collection
• Grafana - Visualization & dashboards
• Loki - Log aggregation
• Alloy - Flexible telemetry collector

Access Grafana at http://localhost:3000 (default: admin/admin)

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📜 License

This project is licensed under the MIT License. See LICENSE file for details.

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🗄️ Database Schema

Users Table

• id
• username
• password_hash
• created_at

Tasks Table

• id
• user_id
• title
• description
• is_completed
• created_at
• updated_at

Indexed on user_id for performance.

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🐳 Getting Started (Docker)

1. Clone the Repository

git clone https://github.com/your-username/task-manager.git
cd task-manager

2. Set Environment Variables

Edit docker/docker-compose.yml or create a .env file:

DEFAULT_USER=admin
DEFAULT_PASS=admin123
DB_USER=postgres
DB_PASSWORD=postgres
DB_NAME=taskdb

3. Run the Application

cd docker && docker-compose up --build -d

4. Access the App

Open your browser:

http://localhost:8080

Login with:

Username: admin
Password: admin123

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💻 Development (Dev Container)

This project includes a .devcontainer setup for seamless development in VS Code.

Steps:

1. Install Dev Containers extension in VS Code
2. Press:

Ctrl + Shift + P → Reopen in Container

Benefits:

• Preconfigured Go environment
• PostgreSQL runs alongside app
• No local setup required
• Consistent dev environment

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🚀 Deployment

1. Provision Infrastructure (Terraform)

Ref: https://registry.terraform.io/providers/bmatcuk/vagrant/latest/docs

cd terraform
terraform init
terraform apply

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2. Configure Server & Deploy (Ansible)

Ref: Debian and AlmaLinux

cd ansible

# Step 1 — install curl, ca-certificates on target hosts
ansible-playbook -i inventory.yml update-install.yml

# Step 2 — install Docker, copy compose files, start the app
ansible-playbook -i inventory.yml deploy.yml

Both playbooks handle Debian (apt) and RedHat / AlmaLinux (dnf) automatically via ansible_os_family.

The deploy strategy pulls the pre-built image from DockerHub — only docker-compose.yml and migrations/ are transferred to each server, making it reproducible on any new host without rebuilding.

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🔄 Deployment Flow

Terraform → Provision VMs
        ↓
Ansible (update-install.yml)
        ↓
Ansible (deploy.yml)
        ↓        
Application running on :8080

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🔧 Cross-Platform Support

Playbook	Debian / Ubuntu	RedHat / AlmaLinux
update-install.yml	apt	dnf
deploy.yml	apt + Docker GPG key	dnf + Docker CE repo

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For detailed more detail logs visit: ./docs/

Monitoring

— Grafana, Prometheus, alertmanager, Loki, and Alloy (Promtail Alternative), blackbox-exporter

Note: Promtail reached end of life (EOL) on March 2, 2026.
https://grafana.com/docs/loki/latest/send-data/promtail/
So, I used Alloy to collect logs and forward them to Loki.

Blackbox Exporter

👨‍💻 Lokendra Bhat

Built with Go for learning and practical DevOps integration.

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