This projects documents the learnings from the Docker Swarm tutorial by Mark Takacs. https://takacsmark.com/docker-swarm-tutorial-for-beginners/ https://www.youtube.com/watch?v=3-7gZS4ePak&t=1950

A machine with a running docker daemon can easily be made to a docker swarm manager or member.

Making the current docker instance a docker swarm manager: docker swarm init It might be necessary to provide a network adapter to create a swarm. docker swarm init --advertise-addr eth1

Deploying a sample application (as a stack) in the swarm:

docker stack deploy -c docker-compose.yml example_app

To update simply redeploy.

To undeploy

docker stack rm example_app

List all nodes (from manager node)

docker node ls

List deployed applications (as stacks) in the swarm:

docker stack ls

List the services in a particular stack

docker stack services example_app

List all services deployed with swarm

docker service ls

List the tasks (1:1 container reservations) of a stack

docker stack ps example_app

To scale a particular serivce (use the name provided by the command docker service ls).

docker service scale example_app_my-nginx=4

docker swarm leave -f

This will remove everything deployed.

version: '3'
services:
  my-nginx:
    image: nginx:latest
    ports:
      - "8080:80"
    networks:
      - mynet
    deploy:
      # replicas: 2
      resources:
        reservations:
          memory: 100m
        limits:
          memory: 300m
      restart_policy:
        condition: any
      # update_config:
      #   parallelism: 2
      #   delay: 10s

networks:
  mynet:

https://linuxhint.com/docker_compose_memory_limits/