Zero-downtime deploys with DigitalOcean, GitHub, and Docker

The guide provides a comprehensive walkthrough on setting up a zero-downtime deployment using DigitalOcean, GitHub, and Docker, specifically targeting Node.js applications but adaptable to other platforms. It begins with the creation of DigitalOcean droplets, a load balancer, and a container registry, followed by detailed steps on generating SSH keys and API tokens for secure communication. The guide outlines the configuration of a GitHub repository and actions to automate the deployment process, ensuring that the main code branch is seamlessly deployed to multiple server instances. Using a health check mechanism, the deployment process ensures continuous service availability, even during updates, by gracefully handling server instance transitions without disrupting service. The document also emphasizes security considerations and recommends additional steps to fortify the infrastructure against unauthorized access.