Docker, Deployment & CI/CD Basics

What you will be able to do

• Explain containers and images and how they differ from virtual machines
• Write a Dockerfile that builds a small, secure image of a Spring Boot app
• Run an application with PostgreSQL using Docker Compose
• Run integration tests against a real database with Testcontainers
• Set up a GitHub Actions pipeline that builds, tests and packages your app
• Deploy a Spring Boot API with a database to a cloud platform and check it is healthy

What it will cover

1. 20.1Why Containers?

   The "works on my machine" problem and how containers solve it.

   Show 5 topics
   • Environments: development, test and production
   • Virtual machines vs containers
   • Images, containers and registries
   • Installing Docker Desktop
   • Running your first container

2. 20.2Docker Essentials

   The everyday Docker commands for running and inspecting containers.

   Show 6 topics
   • docker run, ps, stop, rm and logs
   • Port mapping
   • Environment variables
   • Volumes for data that must survive
   • Running PostgreSQL in a container
   • Shell into a container to debug

3. 20.3Dockerising a Spring Boot App

   Package your application as an image anyone can run.

   Show 6 topics
   • Writing a Dockerfile line by line
   • Choosing a base image
   • Multi-stage builds with Maven
   • Layer caching for faster builds
   • .dockerignore and image size
   • Running as a non-root user

4. 20.4Docker Compose

   Start your app and its database together with one command.

   Show 5 topics
   • docker-compose.yml: services, ports, volumes
   • Networking between containers
   • Health checks and start-up order
   • Environment files and secrets
   • A local development setup with Compose

5. 20.5Integration Tests with Testcontainers

   Test against a real PostgreSQL started for each test run.

   Show 4 topics
   • Why in-memory databases can hide bugs
   • Adding Testcontainers to a Spring Boot project
   • @ServiceConnection and a shared container
   • Running Flyway migrations in tests

6. 20.6CI/CD with GitHub Actions

   Build and test every push automatically.

   Show 6 topics
   • What CI and CD mean
   • Workflow files: triggers, jobs and steps
   • Building and testing a Maven project
   • Caching dependencies
   • Building and pushing a Docker image
   • Branch protection with required checks

7. 20.7Deploying to the Cloud

   Put your API and database online so others can use it.

   Show 6 topics
   • Hosting options for a student project
   • Managed PostgreSQL databases
   • Configuration and secrets in production
   • Deploying a container image
   • Custom domains and HTTPS
   • Automatic deploys from the main branch

8. 20.8Running in Production

   Know whether your deployed app is healthy and what to do when it is not.

   Show 5 topics
   • Health and readiness endpoints with Actuator
   • Reading production logs
   • Basic metrics: response time and error rate
   • Rolling back a bad release
   • Database backups

9. 20.9Deployment Mini Project: Ship ShopLite

   Containerise ShopLite, add a CI pipeline and deploy it with a live URL.

   Show 5 topics
   • Dockerfile and Compose setup
   • Testcontainers integration tests in CI
   • GitHub Actions pipeline from push to deploy
   • Production configuration and secrets
   • Live URL with Swagger UI in your README