Starter packages (dependency sets)

• For Spring apps use Spring Boot starters (starter packages) from Spring Initializer (e.g., spring-boot-starter-web, spring-boot-starter-data-jpa). These bundle common dependencies so you don’t add each library manually.
• Example: if using JPA + REST, include spring-boot-starter-data-jpa and spring-boot-starter-data-rest in pom.xml/build.gradle.

Spring Data REST quick note

• @RepositoryRestResource(path = "customers") automatically exposes repository endpoints (no manual controller needed). Good for quick API prototypes.

Registries

• Docker images are stored in registries. Popular ones: Docker Hub (docker.io) is the main public registry, but private registries (self-hosted or cloud) are common in enterprises.

Docker architecture

• Docker follows a client–server model: the Docker CLI (client) talks to the Docker Engine (daemon).
• Communication uses a socket (Unix socket or TCP/named pipe). Each service exposed over the network uses a port number (e.g., :8080).

Docker daemon (engine)

Daemon ports

• 2376 → Docker daemon over TLS/HTTPS (secure).