Core-os

• https://coreos.com/docs/running-coreos/platforms/libvirt/

docker cluster

• user-data

#cloud-config

---
coreos:
  etcd:
    addr: $public_ipv4:4001
    peer-addr: $public_ipv4:7001
    discovery: https://discovery.etcd.io/122baeb3e193ecb09023ce27a508860b
  etcd2:
    advertise-client-urls: http://$public_ipv4:2379
    initial-advertise-peer-urls: http://$private_ipv4:2380
    listen-client-urls: http://0.0.0.0:2379,http://0.0.0.0:4001
    listen-peer-urls: http://$private_ipv4:2380,http://$private_ipv4:7001
    discovery: https://discovery.etcd.io/122baeb3e193ecb09023ce27a508860b
  fleet:
    public-ip: $public_ipv4
  flannel:
    interface: $public_ipv4
  units:
  - name: etcd.service
    command: start
  - name: fleet.service
    command: start
  - name: docker-tcp.socket
    command: start
    enable: true
    content: |
      [Unit]
      Description=Docker Socket for the API

      [Socket]
      ListenStream=2375
      Service=docker.service
      BindIPv6Only=both

      [Install]
      WantedBy=sockets.target
  - name: httpd.service
    command: start
    enable: true
    content: |
      [Unit]
      Description=httpd
      Requires=docker.service
      After=docker.service

      [Service]
      ExecStart=/usr/bin/docker run -d -p 80:80 --name  own-httpd httpd

      [Install]
      WantedBy=multi-user.target

$num_instances=3
$new_discovery_url="https://discovery.etcd.io/new?size=#{$num_instances}"
if File.exists?('user-data') && ARGV[0].eql?('up')
  require 'open-uri'
  require 'yaml'

  token = open($new_discovery_url).read

  data = YAML.load(IO.readlines('user-data')[1..-1].join)
  if data['coreos'].key? 'etcd'
    data['coreos']['etcd']['discovery'] = token
  end
  if data['coreos'].key? 'etcd2'
    data['coreos']['etcd2']['discovery'] = token
  end

  yaml = YAML.dump(data)
  File.open('user-data', 'w') { |file| file.write("#cloud-config\n\n#{yaml}") }
end
$update_channel='stable'
#$vm_gui = true
$vm_memory = 1024
$vm_cpus = 1

• core@core-01 ~ $ cat CoreGi.service

[Unit]
Description=CoreGI
After=docker.service
Requires=docker.service

[Service]
EnvironmentFile=/etc/environment
User=core

TimeoutStartSec=0
ExecStartPre=-/usr/bin/docker kill coregi
ExecStartPre=-/usr/bin/docker rm coregi
ExecStartPre=/usr/bin/docker pull yodlr/coregi:latest
ExecStart=/usr/bin/docker run --name coregi \
      -p 3000:3000 \
      -v /usr/bin/fleetctl:/usr/bin/fleetctl \
      yodlr/coregi:latest
ExecStop=/usr/bin/docker stop coregi

[X-Fleet]
Global=True

• fleetctl stop CoreGi.service
• fleetctl start CoreGi.service
• fleetctl destroy CoreGi.service
• fleetctl start CoreGi.service
• fleetctl list-units