Core-os

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

docker cluster

• user-data

...
...
...
- 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

---

temp

cat user-data

#cloud-config

---
coreos:
  etcd:
    discovery: https://discovery.etcd.io/d90bc0dcab88d7b5e5e7504ed1df1890
    addr: $public_ipv4:4001
    peer-addr: $public_ipv4:7001
  etcd2:
    advertise-client-urls: http://$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/d90bc0dcab88d7b5e5e7504ed1df1890
  fleet:
    public-ip: $public_ipv4
  flannel:
    interface: $public_ipv4
  units:
  - name: etcd.service
    command: start
  - name: fleet.service
    command: start

cat confg.rb

$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='beta'
$expose_docker_tcp=2375
# Customize VMs
$vm_gui = true
#$vm_memory = 1024
#$vm_cpus = 1