Technical Challenge - Cubos DevOps

Requirements

• Git
• Docker
• Terraform
• Terminal Bash

Configurations

• Cloning and accessing the repository:

  git clone \
  https://github.com/RenanMMaciel/technical-challenge-cubos-devops.git && \
  cd technical-challenge-cubos-devops/

• Make the setup script executable and run the setup script:

  chmod +x ./setup.sh && ./setup.sh

• After running the setup script setup.sh, the following steps will be performed:

  • The script checks if the repository already contains the .env file in the backend directory.

  • If the .env file exists, the script will verify whether the required variables are defined:

    • POSTGRES_USER
    • POSTGRES_PASSWORD
    • POSTGRES_DB
    • DATABASE_ADMIN_PASSWORD

  • If the .env file does not exist or is missing any of the required variables, the script will:

    • Prompt the user to input the missing variables.
    • Either create a new .env file in the backend directory or update the existing one with the missing variables.

• After that, the infrastructure will be set up, and the services will go up.

Services

• Frontend: A static web application served by Nginx, configured to act as a reverse proxy to the backend service.
  Access URL: http://localhost:80

• Backend: A Node.js application that interacts with the database, exposing an API for the frontend to consume.
  Access URL: http://localhost:8080/api

• Database: A PostgreSQL database instance used to store application data, including user credentials and other structured information.
  Access: Accessible internally by backend at database:5432. Use psql for direct access.

• Prometheus: A monitoring and alerting toolkit used to scrape and collect metrics from services frontend, backend and database.
  Access URL: http://localhost:9090

• Grafana: A visualization and analytics platform used to create dashboards and analyze metrics collected by Prometheus.
  Access URL: http://localhost:3000

• Postgres Exporter: A Prometheus exporter used to collect PostgreSQL database metrics, exposing them for Prometheus to scrape.
  Access URL: http://localhost:9187

Networks

• Internal:
  A private network used for communication between backend and database.
  Services: Backend and Database.

• External:
  A public-facing network that connects the frontend service to external clients and allows communication with the backend.
  Services: Frontend and Backend.

• Monitoring:
  A dedicated network for monitoring services like Prometheus and Grafana, ensuring isolation from application traffic.
  Services: Frontend, Backend, Database, Prometheus, Grafana and Postgres Exporter.

Notes

• The setup.sh script is designed to verify the operating system in use and dynamically adjust the DOCKER_HOST variable for the Docker provider in the Terraform configuration. This ensures that the correct communication path is used for Docker, depending on the environment.

  • For Linux systems, the DOCKER_HOST variable is set to unix:///var/run/docker.sock.
  • For Windows systems, the DOCKER_HOST variable is set to npipe:////./pipe/docker_engine.

  The adjusted variable is then passed to the Terraform docker provider configuration, ensuring that all Docker-related operations, such as building images and managing containers, are executed correctly on the target OS.

• All containers are configured with a restart: always policy to ensure that services automatically restart in case of failure or system reboot.

• Persistent volumes (database_data and database_logs) ensure data durability across container restarts.

Repository Tree

technical-challenge-cubos-devops/
├── README.md
├── backend
│   ├── Dockerfile
│   ├── index.js
│   └── package.json
├── database
│   └── script.sh
├── frontend
│   ├── Dockerfile
│   ├── index.html
│   └── nginx.conf
├── monitoring
│   ├── grafana
│   │   └── prometheus-datasource.yml
│   └── prometheus
│       └── prometheus.yml
├── setup.sh
└── terraform
    ├── containers.tf
    ├── images.tf
    ├── networks.tf
    ├── providers.tf
    ├── variables.tf
    └── volumes.tf