Gitlab runner with autoscaling

config.toml

concurrent = 20
check_interval = 0

[[runners]]
  name = "gitlab-runner-master"
  url = "https://gitlab.sourcelab.technology"
  token = "aaabbbccc123"
  executor = "docker+machine"
  limit = 20
  [runners.docker]
    tls_verify = false
    image = "ruby:2.1"
    privileged = false
    disable_cache = false
    volumes = ["/cache"]
  [runners.cache]
  [runners.machine]
    IdleCount = 1
    IdleTime = 600 # 10 min
    MachineDriver = "digitalocean"
    MachineName = "auto-scale-runners-%s.sourcelab.technology"
    OffPeakIdleCount = 0
    OffPeakIdleTime = 0

    MachineOptions = [
	    "digitalocean-image=coreos-stable",
	    "digitalocean-ssh-user=core",
	    "digitalocean-access-token=AAABBBCCC123......",
	    "digitalocean-region=lon1",
	    "digitalocean-size=2gb",
	    "digitalocean-private-networking",
	    # "engine-registry-mirror=http://MY_REGISTRY_IP:6000"
    ]