Ref: https://learn.cantrill.io/courses/docker-fundamentals/lectures/44660846 =OR= https://www.youtube.com/watch?v=L2S9cm43fVY

• Summary:
• Contents:

What is Docker Compose?

• 🔧 Docker Compose is SW used for defining & running multi-container Docker applications
• Handles multiple containers simultaneously in PROD, STAGE, DEV, TEST and CI environments
  • Manages the whole SW Development LifeCycle (SDLC)
• Docker Compose file
  • Written in YAML
    • File name either compose.yaml (new) or docker-compose.yml (old)
  • Configures application's services with rules specifying how to run them
  • Allows to start, stop, or rebuild all the services using a single command

Docker Compose - Commands

• docker compose up - dockerd starts to run/update containers, volumes and NWs
  • Creates, adjusts & deletes resources
  • Smart enough to only adjust what's required to make physical containers match the logical containers in the file
    • e.g. if volumes existed before, it won't (re)create them
• docker compose down - stops & removes all containers specified in Docker Compose file
  • ‼️ Does NOT remove volumes!
    • volumes must be manually removed (if desired)

Docker Compose Summary Diagram