Add HighAvailabilityMode field to 'infrastructure' CRD

Implements enhancement openshift/enhancements#555

Signed-off-by: Ravid Brown <[email protected]>

config/v1/0000_10_config-operator_01_infrastructure.crd.yaml

@@ -173,6 +173,18 @@ spec:
                   used by components like the web console to tell users where to find
                   the Kubernetes API.
                 type: string
+              controlPlaneTopology:
+                description: controlPlaneTopology expresses the expectations for operands
+                  that normally run on control nodes. The default is 'HighlyAvailable',
+                  which represents the behavior operators have in a "normal" cluster.
+                  The 'SingleReplica' mode will be used in single-node deployments
+                  and the operators should not configure the operand for highly-available
+                  operation
+                type: string
+                default: HighlyAvailable
+                enum:
+                - HighlyAvailable
+                - SingleReplica
               etcdDiscoveryDomain:
                 description: 'etcdDiscoveryDomain is the domain used to fetch the
                   SRV records for discovering etcd servers and clients. For more info:
@@ -185,6 +197,19 @@ spec:
                   a human friendly name. Once set it should not be changed. Must be
                   of max length 27 and must have only alphanumeric or hyphen characters.
                 type: string
+              infrastructureTopology:
+                description: infrastructureTopology expresses the expectations for
+                  infrastructure services that do not run on control plane nodes,
+                  usually indicated by a node selector for a `role` value other than
+                  `master`. The default is 'HighlyAvailable', which represents the
+                  behavior operators have in a "normal" cluster. The 'SingleReplica'
+                  mode will be used in single-node deployments and the operators should
+                  not configure the operand for highly-available operation
+                type: string
+                default: HighlyAvailable
+                enum:
+                - HighlyAvailable
+                - SingleReplica
               platform:
                 description: "platform is the underlying infrastructure provider for
                   the cluster. \n Deprecated: Use platformStatus.type instead."

config/v1/types_infrastructure.go

@@ -77,8 +77,36 @@ type InfrastructureStatus struct {
 	// like kubelets, to contact the Kubernetes API server using the
 	// infrastructure provider rather than Kubernetes networking.
 	APIServerInternalURL string `json:"apiServerInternalURI"`
+
+	// controlPlaneTopology expresses the expectations for operands that normally run on control nodes.
+	// The default is 'HighlyAvailable', which represents the behavior operators have in a "normal" cluster.
+	// The 'SingleReplica' mode will be used in single-node deployments
+	// and the operators should not configure the operand for highly-available operation
+	// +kubebuilder:default=HighlyAvailable
+	ControlPlaneTopology TopologyMode `json:"controlPlaneTopology"`
+
+	// infrastructureTopology expresses the expectations for infrastructure services that do not run on control
+	// plane nodes, usually indicated by a node selector for a `role` value
+	// other than `master`.
+	// The default is 'HighlyAvailable', which represents the behavior operators have in a "normal" cluster.
+	// The 'SingleReplica' mode will be used in single-node deployments
+	// and the operators should not configure the operand for highly-available operation
+	// +kubebuilder:default=HighlyAvailable
+	InfrastructureTopology TopologyMode `json:"infrastructureTopology"`
 }
 
+// TopologyMode defines the topology mode of the control/infra nodes.
+// +kubebuilder:validation:Enum=HighlyAvailable;SingleReplica
+type TopologyMode string
+
+const (
+	// "HighlyAvailable" is for operators to configure high-availability as much as possible.
+	HighlyAvailableTopologyMode TopologyMode = "HighlyAvailable"
+
+	// "SingleReplica" is for operators to avoid spending resources for high-availability purpose.
+	SingleReplicaTopologyMode TopologyMode = "SingleReplica"
+)
+
 // PlatformType is a specific supported infrastructure provider.
 // +kubebuilder:validation:Enum="";AWS;Azure;BareMetal;GCP;Libvirt;OpenStack;None;VSphere;oVirt;IBMCloud;KubeVirt
 type PlatformType string