feat: add Multus CNI integration with socket-based readiness

charts/cluster-api-runtime-extensions-nutanix/README.md

@@ -78,6 +78,8 @@ A Helm chart for cluster-api-runtime-extensions-nutanix
 | hooks.cni.cilium.crsStrategy.defaultCiliumConfigMap.name | string | `"cilium"` |  |
 | hooks.cni.cilium.helmAddonStrategy.defaultValueTemplateConfigMap.create | bool | `true` |  |
 | hooks.cni.cilium.helmAddonStrategy.defaultValueTemplateConfigMap.name | string | `"default-cilium-cni-helm-values-template"` |  |
+| hooks.cni.multus.helmAddonStrategy.defaultValueTemplateConfigMap.create | bool | `true` |  |
+| hooks.cni.multus.helmAddonStrategy.defaultValueTemplateConfigMap.name | string | `"default-multus-values-template"` |  |
 | hooks.cosi.controller.helmAddonStrategy.defaultValueTemplateConfigMap.create | bool | `true` |  |
 | hooks.cosi.controller.helmAddonStrategy.defaultValueTemplateConfigMap.name | string | `"default-cosi-controller-helm-values-template"` |  |
 | hooks.csi.aws-ebs.helmAddonStrategy.defaultValueTemplateConfigMap.create | bool | `true` |  |

charts/cluster-api-runtime-extensions-nutanix/addons/cni/multus/values-template.yaml

@@ -0,0 +1,18 @@
+# Multus daemon configuration overrides
+daemonConfig:
+  readinessIndicatorFile: "{{ .SocketPath }}"
+
+{{- if .SocketPath }}
+# Volumes for CNI readiness socket
+volumes:
+  - name: cni-readiness-sock
+    hostPath:
+      path: "{{ .SocketPath }}"
+      type: Socket
+
+# Volume mounts for CNI readiness socket
+volumeMounts:
+  - name: cni-readiness-sock
+    mountPath: "{{ .SocketPath }}"
+    readOnly: true
+{{- end }}

charts/cluster-api-runtime-extensions-nutanix/templates/cni/multus/manifests/helm-addon-installation.yaml

@@ -0,0 +1,12 @@
+# Copyright 2024 Nutanix. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+{{- if .Values.hooks.cni.multus.helmAddonStrategy.defaultValueTemplateConfigMap.create }}
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: '{{ .Values.hooks.cni.multus.helmAddonStrategy.defaultValueTemplateConfigMap.name }}'
+data:
+  values.yaml: |-
+    {{- .Files.Get "addons/cni/multus/values-template.yaml" | nindent 4 }}
+{{- end -}}

charts/cluster-api-runtime-extensions-nutanix/templates/helm-config.yaml

@@ -43,6 +43,10 @@ data:
     ChartName: metallb
     ChartVersion: 0.15.2
     RepositoryURL: '{{ if .Values.helmRepository.enabled }}oci://helm-repository.{{ .Release.Namespace }}.svc/charts{{ else }}https://metallb.github.io/metallb{{ end }}'
+  multus: |
+    ChartName: multus
+    ChartVersion: 0.1.0
+    RepositoryURL: '{{ if .Values.helmRepository.enabled }}oci://helm-repository.{{ .Release.Namespace }}.svc/charts{{ else }}https://mesosphere.github.io/charts/stable/{{ end }}'
   nfd: |
     ChartName: node-feature-discovery
     ChartVersion: 0.18.1

charts/cluster-api-runtime-extensions-nutanix/values.schema.json

@@ -381,6 +381,27 @@
                                     }
                                 }
                             }
+                        },
+                        "multus": {
+                            "type": "object",
+                            "properties": {
+                                "helmAddonStrategy": {
+                                    "type": "object",
+                                    "properties": {
+                                        "defaultValueTemplateConfigMap": {
+                                            "type": "object",
+                                            "properties": {
+                                                "create": {
+                                                    "type": "boolean"
+                                                },
+                                                "name": {
+                                                    "type": "string"
+                                                }
+                                            }
+                                        }
+                                    }
+                                }
+                            }
                         }
                     }
                 },

charts/cluster-api-runtime-extensions-nutanix/values.yaml

@@ -43,6 +43,11 @@ hooks:
         defaultValueTemplateConfigMap:
           create: true
           name: default-cilium-cni-helm-values-template
+    multus:
+      helmAddonStrategy:
+        defaultValueTemplateConfigMap:
+          create: true
+          name: default-multus-values-template
   csi:
     nutanix:
       helmAddonStrategy:

hack/addons/helm-chart-bundler/repos.yaml

@@ -51,6 +51,11 @@ repositories:
     charts:
       metallb:
       - 0.15.2
+  multus:
+    repoURL: https://mesosphere.github.io/charts/stable/
+    charts:
+      multus:
+      - 0.1.0
   node-feature-discovery:
     repoURL: https://kubernetes-sigs.github.io/node-feature-discovery/charts
     charts:

hack/addons/kustomize/multus/kustomization.yaml.tmpl

@@ -0,0 +1,20 @@
+# Copyright 2024 Nutanix. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+metadata:
+  name: multus
+
+sortOptions:
+  order: fifo
+
+helmCharts:
+- name: multus
+  namespace: kube-system
+  repo: https://mesosphere.github.io/charts/stable/
+  releaseName: multus
+  version: 0.1.0
+  includeCRDs: true
+  skipTests: true

pkg/handlers/lifecycle/cni/multus/doc.go

@@ -0,0 +1,24 @@
+// Copyright 2024 Nutanix. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+// Package multus provides a standalone lifecycle handler for Multus CNI that automatically
+// deploys Multus when:
+// - The cluster is on a supported cloud provider (EKS or Nutanix)
+// - A supported CNI provider is configured (Cilium or Calico)
+//
+// MultusHandler implements the cluster lifecycle hooks and:
+// - Detects the cloud provider from the cluster infrastructure
+// - Reads CNI configuration from cluster variables
+// - Gets the socket path for the configured CNI (via cni.SocketPath)
+// - Automatically deploys Multus with socket-based configuration
+//
+// helmAddonStrategy is the internal strategy that handles:
+// - Templating Helm values with the CNI socket path
+// - Deploying Multus using HelmAddon strategy with Go template-based values
+//
+// Multus relies on the readinessIndicatorFile configuration to wait for the primary CNI
+// to be ready, eliminating the need for explicit wait logic in the strategy.
+//
+// This package does NOT expose Multus in the API - it's an internal addon
+// that deploys automatically based on cloud provider and CNI selection.
+package multus

pkg/handlers/lifecycle/cni/multus/handler.go

@@ -0,0 +1,190 @@
+// Copyright 2024 Nutanix. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package multus
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/spf13/pflag"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
+	runtimehooksv1 "sigs.k8s.io/cluster-api/exp/runtime/hooks/api/v1alpha1"
+	ctrl "sigs.k8s.io/controller-runtime"
+	ctrlclient "sigs.k8s.io/controller-runtime/pkg/client"
+
+	"github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/api/v1alpha1"
+	commonhandlers "github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/common/pkg/capi/clustertopology/handlers"
+	"github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/common/pkg/capi/clustertopology/handlers/lifecycle"
+	"github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/common/pkg/capi/clustertopology/variables"
+	capiutils "github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/common/pkg/capi/utils"
+	"github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/pkg/handlers/lifecycle/addons"
+	"github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/pkg/handlers/lifecycle/cni"
+	"github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/pkg/handlers/lifecycle/config"
+	"github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/pkg/handlers/options"
+)
+
+const (
+	defaultMultusReleaseName = "multus"
+	defaultMultusNamespace   = metav1.NamespaceSystem
+)
+
+type MultusConfig struct {
+	*options.GlobalOptions
+
+	helmAddonConfig *addons.HelmAddonConfig
+}
+
+func NewMultusConfig(globalOptions *options.GlobalOptions) *MultusConfig {
+	return &MultusConfig{
+		GlobalOptions: globalOptions,
+		helmAddonConfig: addons.NewHelmAddonConfig(
+			"default-multus-values-template",
+			defaultMultusNamespace,
+			defaultMultusReleaseName,
+		),
+	}
+}
+
+func (m *MultusConfig) AddFlags(prefix string, flags *pflag.FlagSet) {
+	m.helmAddonConfig.AddFlags(prefix+".helm-addon", flags)
+}
+
+type MultusHandler struct {
+	client              ctrlclient.Client
+	config              *MultusConfig
+	helmChartInfoGetter *config.HelmChartGetter
+}
+
+var (
+	_ commonhandlers.Named                   = &MultusHandler{}
+	_ lifecycle.AfterControlPlaneInitialized = &MultusHandler{}
+	_ lifecycle.BeforeClusterUpgrade         = &MultusHandler{}
+)
+
+func New(
+	c ctrlclient.Client,
+	cfg *MultusConfig,
+	helmChartInfoGetter *config.HelmChartGetter,
+) *MultusHandler {
+	return &MultusHandler{
+		client:              c,
+		config:              cfg,
+		helmChartInfoGetter: helmChartInfoGetter,
+	}
+}
+
+func (m *MultusHandler) Name() string {
+	return "MultusHandler"
+}
+
+func (m *MultusHandler) AfterControlPlaneInitialized(
+	ctx context.Context,
+	req *runtimehooksv1.AfterControlPlaneInitializedRequest,
+	resp *runtimehooksv1.AfterControlPlaneInitializedResponse,
+) {
+	commonResponse := &runtimehooksv1.CommonResponse{}
+	m.apply(ctx, &req.Cluster, commonResponse)
+	resp.Status = commonResponse.GetStatus()
+	resp.Message = commonResponse.GetMessage()
+}
+
+func (m *MultusHandler) BeforeClusterUpgrade(
+	ctx context.Context,
+	req *runtimehooksv1.BeforeClusterUpgradeRequest,
+	resp *runtimehooksv1.BeforeClusterUpgradeResponse,
+) {
+	commonResponse := &runtimehooksv1.CommonResponse{}
+	m.apply(ctx, &req.Cluster, commonResponse)
+	resp.Status = commonResponse.GetStatus()
+	resp.Message = commonResponse.GetMessage()
+}
+
+func (m *MultusHandler) apply(
+	ctx context.Context,
+	cluster *clusterv1.Cluster,
+	resp *runtimehooksv1.CommonResponse,
+) {
+	clusterKey := ctrlclient.ObjectKeyFromObject(cluster)
+
+	log := ctrl.LoggerFrom(ctx).WithValues(
+		"cluster",
+		clusterKey,
+	)
+
+	// Check if Multus is supported for this cloud provider
+	provider := capiutils.GetProvider(cluster)
+	if provider != "eks" && provider != "nutanix" {
+		log.V(5).Info(
+			"Multus is not supported for this cloud provider. Skipping Multus deployment.",
+		)
+		return
+	}
+
+	log.Info(fmt.Sprintf("Cluster is %s. Checking CNI configuration for Multus deployment.", provider))
+
+	// Read CNI configuration to detect which CNI is deployed
+	varMap := variables.ClusterVariablesToVariablesMap(cluster.Spec.Topology.Variables)
+
+	cniVar, err := variables.Get[v1alpha1.CNI](
+		varMap,
+		v1alpha1.ClusterConfigVariableName,
+		[]string{"addons", v1alpha1.CNIVariableName}...)
+	if err != nil {
+		if variables.IsNotFoundError(err) {
+			log.V(5).Info("No CNI specified in cluster config. Skipping Multus deployment.")
+			return
+		}
+		log.Error(err, "failed to read CNI configuration from cluster definition")
+		resp.SetStatus(runtimehooksv1.ResponseStatusFailure)
+		resp.SetMessage(fmt.Sprintf("failed to read CNI configuration: %v", err))
+		return
+	}
+
+	// Get socket path for the CNI provider
+	socketPath, err := cni.SocketPath(cniVar.Provider)
+	if err != nil {
+		log.V(5).
+			Info(fmt.Sprintf("Multus does not support CNI provider: %s. Skipping Multus deployment.", cniVar.Provider))
+		return
+	}
+
+	log.Info(fmt.Sprintf("Auto-deploying Multus for %s cluster with %s CNI", provider, cniVar.Provider))
+
+	// Get helm chart configuration
+	helmChart, err := m.helmChartInfoGetter.For(ctx, log, config.Multus)
+	if err != nil {
+		log.Error(
+			err,
+			"failed to get configmap with helm settings",
+		)
+		resp.SetStatus(runtimehooksv1.ResponseStatusFailure)
+		resp.SetMessage(
+			fmt.Sprintf("failed to get configuration to create helm addon: %v",
+				err,
+			),
+		)
+		return
+	}
+
+	// Create and apply helm addon using existing addons package
+	targetNamespace := m.config.DefaultsNamespace()
+	strategy := addons.NewHelmAddonApplier(
+		m.config.helmAddonConfig,
+		m.client,
+		helmChart,
+	).
+		WithValueTemplater(templateValuesFunc(socketPath)).
+		WithDefaultWaiter()
+
+	if err := strategy.Apply(ctx, cluster, targetNamespace, log); err != nil {
+		log.Error(err, "failed to deploy Multus")
+		resp.SetStatus(runtimehooksv1.ResponseStatusFailure)
+		resp.SetMessage(fmt.Sprintf("failed to deploy Multus: %v", err))
+		return
+	}
+
+	resp.SetStatus(runtimehooksv1.ResponseStatusSuccess)
+	resp.SetMessage("Multus deployed successfully")
+}

pkg/handlers/lifecycle/cni/multus/template.go

@@ -0,0 +1,39 @@
+// Copyright 2024 Nutanix. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package multus
+
+import (
+	"bytes"
+	"fmt"
+	"text/template"
+
+	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
+)
+
+// templateValuesFunc returns a template function that parses the Multus values template
+// and replaces socket-related placeholders with the provided socket path.
+func templateValuesFunc(socketPath string) func(*clusterv1.Cluster, string) (string, error) {
+	return func(_ *clusterv1.Cluster, valuesTemplate string) (string, error) {
+		t, err := template.New("").Parse(valuesTemplate)
+		if err != nil {
+			return "", fmt.Errorf("failed to parse Multus values template: %w", err)
+		}
+
+		type input struct {
+			SocketPath string
+		}
+
+		templateInput := input{
+			SocketPath: socketPath,
+		}
+
+		var b bytes.Buffer
+		err = t.Execute(&b, templateInput)
+		if err != nil {
+			return "", fmt.Errorf("failed to template Multus values: %w", err)
+		}
+
+		return b.String(), nil
+	}
+}