OCPEDGE-1749: [TNF] Updated bare-metal init sequence to detach control-plane nodes in Two Node OpenShift.

Two Node OpenShift (TNF) is DevPreview in 4.19. In order to ensure that ironic doesn't try to manage
the power state of the nodes, we add a check for the DualReplica topology after the control-plane nodes
are provisioned during bootstrapping and detach them from ironic.

In a future release, when fencing is enabled, it will be important to enforce that this remains an invariant
for the DualReplica control-plane topology. There is currently nothing preventing the annotation that detaches
these nodes from being removed.

Author: jaypoulz

data/data/bootstrap/baremetal/files/usr/local/bin/master-bmh-update.sh

@@ -17,6 +17,24 @@ while [ "$(oc get bmh -n openshift-machine-api -l installer.openshift.io/role=co
     sleep 20
 done
 
+# Pause control-plane management via ironic for Two-Node OpenShift with Fencing (TNF), since this conflicts with how TNF achieves HA
+TNF_TOPOLOGY="DualReplica"
+
+echo "Looking up control-plane topology"
+CONTROL_PLANE_TOPOLOGY=$(oc get infrastructures.config.openshift.io cluster -o json | jq -r '.status.controlPlaneTopology')
+if [ -z "${CONTROL_PLANE_TOPOLOGY}" ]; then
+    echo "Error: couldn't lookup control-plane topology" >&2
+    exit 1
+elif [ "${CONTROL_PLANE_TOPOLOGY}" = "${TNF_TOPOLOGY}" ]; then
+    echo "Control-plane topology set to '${TNF_TOPOLOGY}'; setting the control-plane hosts to detached"
+    while ! oc annotate --overwrite bmh -n openshift-machine-api -l installer.openshift.io/role=control-plane baremetalhost.metal3.io/detached="" ; do
+        sleep 5
+        echo "Setting control-plane nodes to detached failed, retrying"
+    done
+else
+    echo "Control-plane topology set to '${CONTROL_PLANE_TOPOLOGY}'; no further actions required"
+fi
+
 # Shut down ironic containers so that the API VIP can fail over to the control
 # plane.
 echo "Stopping provisioning services..."

pkg/types/validation/installconfig.go

@@ -1600,11 +1600,8 @@ func validateFencingCredentials(installConfig *types.InstallConfig) (errors fiel
 func validateFencingForPlatform(config *types.InstallConfig, fldPath *field.Path) field.ErrorList {
 	errs := field.ErrorList{}
 	switch {
-	case config.None != nil, config.External != nil:
-	case config.BareMetal != nil:
-		if len(config.Platform.BareMetal.Hosts) > 0 {
-			errs = append(errs, field.Forbidden(fldPath, "fencing is mutually exclusive with hosts, please remove either of them"))
-		}
+	case config.None != nil, config.External != nil, config.BareMetal != nil:
+		// Allowed platforms
 	default:
 		errs = append(errs, field.Forbidden(fldPath, fmt.Sprintf("fencing is only supported on baremetal, external or none platforms, instead %s platform was found", config.Platform.Name())))
 	}

pkg/types/validation/installconfig_test.go

@@ -2814,6 +2814,7 @@ func TestValidateTNF(t *testing.T) {
 		},
 		{
 			config: installConfig().
+				PlatformBMWithHosts().
 				MachinePoolCP(machinePool().
 					Credential(c1(), c2())).
 				CpReplicas(2).
@@ -2831,6 +2832,7 @@ func TestValidateTNF(t *testing.T) {
 		},
 		{
 			config: installConfig().
+				PlatformBMWithHosts().
 				MachinePoolArbiter(machinePool()).
 				MachinePoolCP(machinePool().Credential(c1(), c2())).
 				ArbiterReplicas(1).
@@ -2840,6 +2842,7 @@ func TestValidateTNF(t *testing.T) {
 		},
 		{
 			config: installConfig().
+				PlatformBMWithHosts().
 				MachinePoolArbiter(machinePool()).
 				MachinePoolCP(machinePool().Credential(c1(), c2(), c3())).
 				ArbiterReplicas(1).
@@ -2920,8 +2923,8 @@ func TestValidateTNF(t *testing.T) {
 					Credential(c1(), c2())).
 				CpReplicas(2).
 				build(),
-			name:     "fencing_hosts_mutually_exclusive",
-			expected: "controlPlane.fencing: Forbidden: fencing is mutually exclusive with hosts, please remove either of them",
+			name:     "tnf_supported_platforms",
+			expected: "",
 		},
 		{
 			config: installConfig().
@@ -2930,7 +2933,7 @@ func TestValidateTNF(t *testing.T) {
 					Credential(c1(), c2())).
 				CpReplicas(2).
 				build(),
-			name:     "supported_platforms",
+			name:     "tnf_unsupported_platform",
 			expected: "controlPlane.fencing: Forbidden: fencing is only supported on baremetal, external or none platforms, instead aws platform was found",
 		},
 	}
@@ -3060,10 +3063,8 @@ type installConfigBuilder struct {
 }
 
 func installConfig() *installConfigBuilder {
-	bmPlatform := validBareMetalPlatform()
-	bmPlatform.Hosts = nil
 	return &installConfigBuilder{
-		InstallConfig: types.InstallConfig{Platform: types.Platform{BareMetal: bmPlatform}},
+		InstallConfig: types.InstallConfig{},
 	}
 }