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

@@ -172,6 +172,18 @@ spec:
                 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 (developer
+                and production) for example, 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: https://github.com/etcd-io/etcd/blob/329be66e8b3f9e2e6af83c123ff89297e49ebd15/Documentation/op-guide/clustering.md#dns-discovery
@@ -183,6 +195,18 @@ spec:
                 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 operands
+                that normally run on infrastructure 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 (developer
+                and production) for example, 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 +77,34 @@ 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 (developer and production) for example,
+	// and the operators should not configure the operand for highly-available operation
+	// +kubebuilder:default=HighlyAvailable
+	ControlPlaneTopology TopologyMode `json:"controlPlaneTopology"`
+
+	// InfrastructureTopology expresses the expectations for operands that normally run on infrastructure 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 (developer and production) for example,
+	// 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