Add SchedulingConstraints to Etcd spec

api/v1alpha1/etcd_types.go

@@ -242,6 +242,20 @@ type SharedConfig struct {
 	AutoCompactionRetention *string `json:"autoCompactionRetention,omitempty"`
 }
 
+// SchedulingConstraints defines the different scheduling constraints that must be applied to the
+// pod spec in the etcd statefulset.
+// Currently supported constraints are Affinity and TopologySpreadConstraints.
+type SchedulingConstraints struct {
+	// Affinity defines the various affinity and anti-affinity rules for a pod
+	// that are honoured by the kube-scheduler.
+	// +optional
+	Affinity *corev1.Affinity `json:"affinity,omitempty"`
+	// TopologySpreadConstraints describes how a group of pods ought to spread across topology domains,
+	// that are honoured by the kube-scheduler.
+	// +optional
+	TopologySpreadConstraints []corev1.TopologySpreadConstraint `json:"topologySpreadConstraints,omitempty"`
+}
+
 // EtcdSpec defines the desired state of Etcd
 type EtcdSpec struct {
 	// selector is a label query over pods that should match the replica count.
@@ -258,6 +272,8 @@ type EtcdSpec struct {
 	Backup BackupSpec `json:"backup"`
 	// +optional
 	Common SharedConfig `json:"sharedConfig,omitempty"`
+	// +optional
+	SchedulingConstraints SchedulingConstraints `json:"schedulingConstraints,omitempty"`
 	// +required
 	Replicas int32 `json:"replicas"`
 	// PriorityClassName is the name of a priority class that shall be used for the etcd pods.

charts/etcd/templates/etcd-statefulset.yaml

@@ -46,6 +46,16 @@ spec:
       priorityClassName: {{ .Values.priorityClassName }}
 {{- end }}
       serviceAccountName: {{ .Values.serviceAccountName }}
+{{- if .Values.schedulingConstraints }}
+{{- if .Values.schedulingConstraints.affinity }}
+      affinity:
+{{ toYaml .Values.schedulingConstraints.affinity | indent 8 }}
+{{- end }}
+{{- if .Values.schedulingConstraints.topologySpreadConstraints }}
+      topologySpreadConstraints:
+{{ toYaml .Values.schedulingConstraints.topologySpreadConstraints | indent 6 }}
+{{- end }}
+{{- end }}
       containers:
       - name: etcd
         image: {{ .Values.etcd.image }}

charts/etcd/values.yaml

@@ -79,6 +79,29 @@ sharedConfig:
   autoCompactionMode: periodic
   autoCompactionRetention: "30m"
 
+schedulingConstraints: {}
+  ## affinity defines the various affinity and anti-affinity rules for a pod
+  ## that are honoured by the kube-scheduler.
+  # affinity:
+  #   podAffinity:
+  #     requiredDuringSchedulingIgnoredDuringExecution:
+  #     - labelSelector:
+  #         matchExpressions:
+  #         - key: key
+  #           operator: In
+  #           values:
+  #           - value
+  #       topologyKey: topology.kubernetes.io/zone
+  ## topologySpreadConstraints describes how a group of pods ought to spread across topology domains,
+  ## that are honoured by the kube-scheduler.
+  # topologySpreadConstraints:
+  # - maxSkew: 1
+  #   topologyKey: topology.kubernetes.io/zone
+  #   whenUnsatisfiable: DoNotSchedule
+  #   labelSelector:
+  #     matchLabels:
+  #       key: value
+
 volumeClaimTemplateName: test
 storageClass: ""
 storageCapacity: 16Gi