• Create Dockerfile which lets us define things the image needs
  • Can run commands to init the container
  • Can define command to run once container set uo
• Building the image
  • docker build -t test_docker_app .
• Running the container
  • Map real port 4000 to virtual port 80
  • docker run -p 4000:80 friendlyhello
• Tag the docker image
  • docker tag image stefanolupo/<image_name>:<version(e.g. latest)>
  • docker image ls
• Push to docker hub
  • docker push stefanolupo/<image_name>:tag
• Run anywhere (auto pulls the container)
  • docker run -p 4000:80 stefanolupo/<image_name>:tag

Used for deploying multiple instances of image on a single machine

Creates 5 instances of the containers and limits their resources. Also hooks up the port forwards. Create a default network webnet which handles load balancing across the instances

version: "3"
services:
  web:
    # replace username/repo:tag with your name and image details
    image: username/repo:tag
    deploy:
      replicas: 5
      resources:
        limits:
          cpus: "0.1"
          memory: 50M
      restart_policy:
        condition: on-failure
    ports:
      - "4000:80"
    networks:
      - webnet
networks:
  webnet:

docker swarm init

docker stack deploy -c docker-compose.yml <service_name>

• List services docker service ls
• List processes (tasks) in service: docker service ps <service_name>

• Just adjust # replicas and rerun deploy

• Take down app: docker stack rm <service_name>
• Take down swarm: docker swarm leave --force

• Uses docker-machine to manage machines in cluster
• Swarms are group of focker machines joined into a cluster
• Docker commands are now executed cluster wide by a swarm manager
• Swarm managers can use strategies for assigning containers to nodes
  • Global: all get one
  • Emptiest node: prioritize those with least work currently
• Swarm managers are the only nodes who can orchestrate cluster
• Note: Docker swarm management port is 2377 - always use this (just leave default)
• Note: Docker daemon runs on port 2376 - awlays use this (just leave default)

Can use docker itself to provision nodes for a bunch of aaS providers.

• Note: Probably need to set application default credentials
  • gcloud auth application-default login
• This handles installing docker, creating SSH keys and opening firewall ports automatically

# Add docker machine of an existing instance
docker-machine create \
--driver google \
--google-project ndn-thesis
--google-address <ip_add> \
--google-zone europe-west4-a
--google-use-existing
<google_machine_name>

# Add docker machine from new instance
docker-machine create \
--driver google \
--google-project ndn-thesis \
--google-machine-type f1-micro \ # Chepaest 
--google-zone europe-west4-a
<machine_name>

• Now see the machines we have docker-machine ls
  • Might need to extend timeout docker-machine ls -t 20

• IPs come from docker-machine ls

# Make <mach_name> the swarm leader (not sure about auto choosing IP)
docker-machine ssh <mach_name> "docker swarm init --advertise-addr <ip_to_use>"

# Get other machines to join the swarm
docker-machine ssh <other_mach_name> "docker swarm join --token <token> <ip>