When it comes to managing multiple Docker containers that are related to each other, using plain Docker commands requires remembering the relationships between containers.
However, with docker-compose, managing multiple containers becomes straightforward through easy definition of multi-container services.

Introduction

• Docker for Mac defaults to docker-compose.
• A tool written in Python.
• Defined by YAML.
• Configuration file: docker-compose.yml.
• Depends on the Docker version.

Official Documentation: docker-compose

Configuration File Structure

docker-compose.yml consists of two main parts:

• version (must be a string).
• services
  • key -> DNS name (hostname)

Example of docker-compose

Other Tools

docker-swarm

• Considered as a counterpart to Kubernetes.
• Convenient deployment (less preparation compared to Kubernetes).
• High availability HA .
• Cost-effective.

Components (Node)

• Divided into two nodes:
  • Manager:
    • Assigns tasks to worker nodes.
    • Also acts as a worker node.
    • Controls the entire Docker Swarm deployment.
    • Primary control node.
    • If it fails, the entire Docker Swarm fails.
    • Can have multiple managers, but only one &$%^^#???
  • Worker:
    • Assigned tasks but does not actively assign tasks.
    • Unaware of other worker nodes.
• Rolling updates can be performed at any time.
• Under all nodes:
  • Service:
    • Represents a container.
    • Starting a service does not mean starting a container.
    • Can perform health checks on containers.
    • Services can start multiple containers (replicas).
  • Task:
    • Primarily initiated by the Service.
    • Represents commands executed within a Docker container.
    • Tasks execute on a node until completion.