Enable Single Node Cluster deployment via tanzu CLI (vmware-tanzu#3674)

Co-authored-by: Jamie Monserrate <monserratej@vmware.com>

Co-authored-by: Jamie Monserrate <monserratej@vmware.com>

packages/tkg-clusterclass-vsphere/bundle/config/upstream/base.yaml

@@ -400,7 +400,7 @@ spec:
                   type: string
                 default: []
   - name: worker
-    required: true
+    required: false
     schema:
       openAPIV3Schema:
         type: object
@@ -457,6 +457,12 @@ spec:
       openAPIV3Schema:
         type: object
         properties: {}
+  - name: controlPlaneTaint
+    required: false
+    schema:
+      openAPIV3Schema:
+        type: boolean
+        default: true
   patches:
   - name: vsphereClusterTemplate
     definitions:
@@ -1402,6 +1408,21 @@ spec:
               - level: Metadata
                 omitStages:
                   - "RequestReceived"
+  - name: controlPlaneTaint
+    enabledIf: '{{ not .controlPlaneTaint }}'
+    definitions:
+    - selector:
+        apiVersion: controlplane.cluster.x-k8s.io/v1beta1
+        kind: KubeadmControlPlaneTemplate
+        matchResources:
+          controlPlane: true
+      jsonPatches:
+      - op: add
+        path: /spec/template/spec/kubeadmConfigSpec/initConfiguration/nodeRegistration/taints
+        value: []
+      - op: add
+        path: /spec/template/spec/kubeadmConfigSpec/joinConfiguration/nodeRegistration/taints
+        value: []
   - name: windows
     definitions:
     - selector:

providers/infrastructure-vsphere/v1.4.1/cconly/base.yaml

@@ -400,7 +400,7 @@ spec:
                   type: string
                 default: []
   - name: worker
-    required: true
+    required: false
     schema:
       openAPIV3Schema:
         type: object
@@ -457,6 +457,12 @@ spec:
       openAPIV3Schema:
         type: object
         properties: {}
+  - name: controlPlaneTaint
+    required: false
+    schema:
+      openAPIV3Schema:
+        type: boolean
+        default: true
   patches:
   - name: vsphereClusterTemplate
     definitions:
@@ -1402,6 +1408,21 @@ spec:
               - level: Metadata
                 omitStages:
                   - "RequestReceived"
+  - name: controlPlaneTaint
+    enabledIf: '{{ not .controlPlaneTaint }}'
+    definitions:
+    - selector:
+        apiVersion: controlplane.cluster.x-k8s.io/v1beta1
+        kind: KubeadmControlPlaneTemplate
+        matchResources:
+          controlPlane: true
+      jsonPatches:
+      - op: add
+        path: /spec/template/spec/kubeadmConfigSpec/initConfiguration/nodeRegistration/taints
+        value: []
+      - op: add
+        path: /spec/template/spec/kubeadmConfigSpec/joinConfiguration/nodeRegistration/taints
+        value: []
   - name: windows
     definitions:
     - selector:

tkg/client/client.go

@@ -236,6 +236,7 @@ type TkgClient struct {
 	tkgConfigPathsClient     tkgconfigpaths.Client
 	clusterKubeConfig        *types.ClusterKubeConfig
 	clusterClientFactory     clusterclient.ClusterClientFactory
+	vcClientFactory          vc.VcClientFactory
 	featureFlagClient        FeatureFlagClient
 }
 
@@ -253,6 +254,7 @@ type Options struct {
 	TKGPathsClient           tkgconfigpaths.Client
 	ClusterKubeConfig        *types.ClusterKubeConfig
 	ClusterClientFactory     clusterclient.ClusterClientFactory
+	VcClientFactory          vc.VcClientFactory
 	FeatureFlagClient        FeatureFlagClient
 }
 
@@ -283,6 +285,7 @@ func New(options Options) (*TkgClient, error) { // nolint:gocritic
 		tkgConfigPathsClient:     options.TKGPathsClient,
 		clusterKubeConfig:        options.ClusterKubeConfig,
 		clusterClientFactory:     options.ClusterClientFactory,
+		vcClientFactory:          options.VcClientFactory,
 		featureFlagClient:        options.FeatureFlagClient,
 	}, nil
 }

tkg/client/cluster.go

@@ -4,15 +4,21 @@
 package client
 
 import (
+	"bytes"
 	"fmt"
+	"io"
 	"os"
 	"path/filepath"
 	"strconv"
 	"strings"
 	"time"
 
+	"gopkg.in/yaml.v3"
+
 	"github.com/pkg/errors"
+	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/util/version"
+	capi "sigs.k8s.io/cluster-api/api/v1beta1"
 	clusterctlv1 "sigs.k8s.io/cluster-api/cmd/clusterctl/api/v1alpha3"
 	clusterctlclient "sigs.k8s.io/cluster-api/cmd/clusterctl/client"
 	"sigs.k8s.io/cluster-api/cmd/clusterctl/client/cluster"
@@ -25,6 +31,7 @@ import (
 	"github.com/vmware-tanzu/tanzu-framework/tkg/log"
 	"github.com/vmware-tanzu/tanzu-framework/tkg/tkgconfighelper"
 	"github.com/vmware-tanzu/tanzu-framework/tkg/utils"
+	"github.com/vmware-tanzu/tanzu-framework/util/topology"
 )
 
 const (
@@ -95,7 +102,7 @@ func (c *TkgClient) CreateCluster(options *CreateClusterOptions, waitForCluster
 		GetClientTimeout:  3 * time.Second,
 		OperationTimeout:  c.timeout,
 	}
-	regionalClusterClient, err := clusterclient.NewClient(options.Kubeconfig.Path, options.Kubeconfig.Context, clusterclientOptions)
+	regionalClusterClient, err := c.clusterClientFactory.NewClient(options.Kubeconfig.Path, options.Kubeconfig.Context, clusterclientOptions)
 	if err != nil {
 		return false, errors.Wrap(err, "unable to get cluster client while creating cluster")
 	}
@@ -141,6 +148,11 @@ func (c *TkgClient) CreateCluster(options *CreateClusterOptions, waitForCluster
 		if err != nil {
 			return false, errors.Wrap(err, "unable to get cluster configuration")
 		}
+
+		err = validateConfigForSingleNodeCluster(bytes, options, c)
+		if err != nil {
+			return false, err
+		}
 	} else {
 		bytes, err = c.getClusterConfigurationBytes(&options.ClusterConfigOptions, infraProviderName, isManagementCluster, options.IsWindowsWorkloadCluster)
 		if err != nil {
@@ -862,3 +874,63 @@ func (c *TkgClient) ValidateManagementClusterVersionWithCLI(regionalClusterClien
 
 	return nil
 }
+
+// validateConfigForSingleNodeCluster validates that the controlPlaneTaint CC variable is not set for the single node workload cluster, otherwise returns error
+func validateConfigForSingleNodeCluster(stream []byte, options *CreateClusterOptions, tkgClient *TkgClient) error {
+	cluster, err := getClusterObjectFromYaml(stream)
+	if err != nil {
+		return err
+	}
+
+	if !topology.IsSingleNodeCluster(cluster) {
+		return nil
+	}
+
+	controlPlaneTaint := true
+	err = topology.GetVariable(cluster, "controlPlaneTaint", &controlPlaneTaint)
+	if err != nil {
+		return errors.Wrap(err, "failed to get CC variable controlPlaneTaint")
+	}
+
+	// Do not allow the creation of single node clusters without the feature gate.
+	if !tkgClient.IsFeatureActivated(constants.FeatureFlagSingleNodeClusters) {
+		return errors.New("Worker count cannot be 0, minimum worker count required is 1")
+	}
+
+	if controlPlaneTaint {
+		return errors.New(fmt.Sprintf("unable to create single node cluster %s as control plane node has taint", options.ClusterName))
+	}
+
+	return nil
+}
+
+func getClusterObjectFromYaml(stream []byte) (*capi.Cluster, error) {
+	clusterYaml, err := findClusterDefinitionIn(stream)
+	if err != nil {
+		return nil, err
+	}
+
+	cluster := &capi.Cluster{}
+	err = runtime.DefaultUnstructuredConverter.FromUnstructured(clusterYaml, cluster)
+	if err != nil {
+		return nil, errors.Wrap(err, "unable to convert yaml to structured format")
+	}
+	return cluster, nil
+}
+
+func findClusterDefinitionIn(stream []byte) (map[string]interface{}, error) {
+	clusterYaml := make(map[string]interface{})
+	decoder := yaml.NewDecoder(bytes.NewBufferString(string(stream)))
+	for {
+		if err := decoder.Decode(&clusterYaml); err != nil {
+			if err == io.EOF {
+				break
+			}
+			return clusterYaml, errors.Wrap(err, "unable to read cluster yaml")
+		}
+		if clusterYaml["kind"] == constants.KindCluster {
+			break
+		}
+	}
+	return clusterYaml, nil
+}