HTTPS-PORTAL is a Docker image that automates HTTPS setup using Nginx and Let's Encrypt. It provides a fully automated reverse proxy that obtains SSL certificates, configures Nginx, and handles renewal. The container runs multiple supervised processes via s6-overlay: Nginx, docker-gen (for automatic container discovery), cron (for certificate renewal), and a dynamic environment watcher. Configuration is driven by environment variables, primarily the `DOMAINS` variable which supports a rich syntax for specifying upstreams, redirects, basic auth, access restrictions, custom ports, and per-domain stages. The codebase is primarily Ruby scripts that parse domain descriptors, generate Nginx configuration from ERB templates, and orchestrate certificate signing via acme-tiny. The architecture is clean and modular, with clear separation between domain parsing, certificate management, and Nginx configuration generation. The repository includes comprehensive integration tests using Docker Compose and RSpec.