fix(*): Use cgroupfs driver in both host and builder docker.

The (CorOS) default of systemd might have some problems.
See also coreos/bugs#1435
moby/moby#21444 and
moby/moby#21678

builder/docker/docker.go

@@ -72,6 +72,8 @@ func Start(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
 		"192.168.0.0/16",
 		"--insecure-registry",
 		"100.64.0.0/10",
+		"--exec-opt",
+		"native.cgroupdriver=cgroupfs",
 	}
 
 	// For overlay-ish filesystems, force the overlay to kick in if it exists.

contrib/coreos/user-data.example

@@ -43,6 +43,10 @@ coreos:
       enable: false
     - name: docker.service
       drop-ins:
+      - name: 00-reset-environment.conf
+        content: |
+          [Service]
+          Environment=
       - name: 10-require-flannel.conf
         content: |
           [Unit]
@@ -52,6 +56,10 @@ coreos:
         content: |
           [Service]
           Environment="DOCKER_OPTS=--insecure-registry 10.0.0.0/8 --insecure-registry 172.16.0.0/12 --insecure-registry 192.168.0.0/16 --insecure-registry 100.64.0.0/10"
+      - name: 60-cgroup-driver.conf
+        content: |
+          [Service]
+          Environment="DOCKER_CGROUPS=--exec-opt native.cgroupdriver=cgroupfs"
     - name: flanneld.service
       command: start
       drop-ins: