Enable kubeadm etcd mode (#4818)

* Enable kubeadm etcd mode

Uses cert commands from kubeadm experimental control plane to
enable non-master nodes to obtain etcd certs.

Related story: PROD-29434

Change-Id: Idafa1d223e5c6ceadf819b6f9c06adf4c4f74178

* Add validation checks and exclude calico kdd mode

Change-Id: Ic234f5e71261d33191376e70d438f9f6d35f358c

* Move etcd mode test to ubuntu flannel HA job

Change-Id: I9af6fd80a1bbb1692ab10d6da095eb368f6bc732

* rename etcd_mode to etcd_kubeadm_enabled

Change-Id: Ib196d6c8a52f48cae370b026f7687ff9ca69c172

roles/kubernetes/master/defaults/main/etcd.yml

@@ -0,0 +1,32 @@
+---
+# Note: This does not set up DNS entries. It simply adds the following DNS
+# entries to the certificate
+etcd_cert_alt_names:
+  - "etcd.kube-system.svc.{{ dns_domain }}"
+  - "etcd.kube-system.svc"
+  - "etcd.kube-system"
+  - "etcd"
+etcd_cert_alt_ips: []
+
+etcd_heartbeat_interval: "250"
+etcd_election_timeout: "5000"
+
+# etcd_snapshot_count: "10000"
+
+# Parameters for ionice
+# -c takes an integer between 0 and 3 or one of the strings none, realtime, best-effort or idle.
+# -n takes an integer between 0 (highest priority) and 7 (lowest priority)
+# etcd_ionice: "-c2 -n0"
+
+etcd_metrics: "basic"
+
+## A dictionary of extra environment variables to add to etcd.env, formatted like:
+##  etcd_extra_vars:
+##    var1: "value1"
+##    var2: "value2"
+## Note this is different from the etcd role with ETCD_ prfexi, caps, and underscores
+etcd_extra_vars: {}
+
+# etcd_quota_backend_bytes: "2G"
+
+etcd_compaction_retention: "8"

roles/kubernetes/master/defaults/main/main.yml

@@ -2,6 +2,12 @@
 # disable upgrade cluster
 upgrade_cluster_setup: false
 
+# Enable kubeadm experimental control plane
+kubeadm_control_plane: false
+
+# Experimental kubeadm etcd deployment mode. Available only for new deployment
+etcd_kubeadm_enabled: false
+
 # An experimental dev/test only dynamic volumes provisioner,
 # for PetSets. Works for kube>=v1.3 only.
 kube_hostpath_dynamic_provisioner: "false"