Give etcd pods system-cluster-critical priority

Again unlikely to matter since master nodes aren't expected to run out of
capacity, done mostly for completeness (all pods should usually have a
priority defined if the cluster is running with PodPriority enabled).

pkg/model/components/etcdmanager/model.go

@@ -445,6 +445,7 @@ func (b *EtcdManagerBuilder) buildPod(etcdCluster *kops.EtcdClusterSpec) (*v1.Po
 	}
 
 	kubemanifest.MarkPodAsCritical(pod)
+	kubemanifest.MarkPodAsClusterCritical(pod)
 
 	return pod, nil
 }

pkg/model/components/etcdmanager/tests/minimal/tasks.yaml

@@ -108,6 +108,7 @@ Contents:
           name: varlogetcd
       hostNetwork: true
       hostPID: true
+      priorityClassName: system-cluster-critical
       tolerations:
       - key: CriticalAddonsOnly
         operator: Exists
@@ -178,6 +179,7 @@ Contents:
           name: varlogetcd
       hostNetwork: true
       hostPID: true
+      priorityClassName: system-cluster-critical
       tolerations:
       - key: CriticalAddonsOnly
         operator: Exists

protokube/pkg/protokube/etcd_manifest.go

@@ -165,6 +165,7 @@ func BuildEtcdManifest(c *EtcdCluster) *v1.Pod {
 	}
 
 	kubemanifest.MarkPodAsCritical(pod)
+	kubemanifest.MarkPodAsClusterCritical(pod)
 
 	return pod
 }

protokube/tests/integration/build_etcd_manifest/main/etcd_env_vars.yaml

@@ -93,6 +93,7 @@ spec:
       name: hosts
       readOnly: true
   hostNetwork: true
+  priorityClassName: system-cluster-critical
   tolerations:
   - key: CriticalAddonsOnly
     operator: Exists

protokube/tests/integration/build_etcd_manifest/main/non_tls.yaml

@@ -87,6 +87,7 @@ spec:
       name: hosts
       readOnly: true
   hostNetwork: true
+  priorityClassName: system-cluster-critical
   tolerations:
   - key: CriticalAddonsOnly
     operator: Exists

protokube/tests/integration/build_etcd_manifest/main/tls.yaml

@@ -106,6 +106,7 @@ spec:
       name: srvkubernetes
       readOnly: true
   hostNetwork: true
+  priorityClassName: system-cluster-critical
   tolerations:
   - key: CriticalAddonsOnly
     operator: Exists