Run Envoy Gateway like DaemonSet

api/v1alpha1/envoyproxy_helpers.go

@@ -70,11 +70,20 @@ func (r *EnvoyProxyProvider) GetEnvoyProxyKubeProvider() *EnvoyProxyKubernetesPr
 		return r.Kubernetes
 	}
 
-	if r.Kubernetes.EnvoyDeployment == nil {
+	// if EnvoyDeployment and EnvoyDaemonSet are both nil, use EnvoyDeployment
+	if r.Kubernetes.EnvoyDeployment == nil && r.Kubernetes.EnvoyDaemonSet == nil {
 		r.Kubernetes.EnvoyDeployment = DefaultKubernetesDeployment(DefaultEnvoyProxyImage)
 	}
 
-	r.Kubernetes.EnvoyDeployment.defaultKubernetesDeploymentSpec(DefaultEnvoyProxyImage)
+	// if use EnvoyDeployment, set default values
+	if r.Kubernetes.EnvoyDeployment != nil {
+		r.Kubernetes.EnvoyDeployment.defaultKubernetesDeploymentSpec(DefaultEnvoyProxyImage)
+	}
+
+	// if use EnvoyDaemonSet, set default values
+	if r.Kubernetes.EnvoyDaemonSet != nil {
+		r.Kubernetes.EnvoyDaemonSet.defaultKubernetesDaemonSetSpec(DefaultEnvoyProxyImage)
+	}
 
 	if r.Kubernetes.EnvoyService == nil {
 		r.Kubernetes.EnvoyService = DefaultKubernetesService()

api/v1alpha1/envoyproxy_types.go

@@ -218,6 +218,9 @@ type ShutdownConfig struct {
 	MinDrainDuration *metav1.Duration `json:"minDrainDuration,omitempty"`
 }
 
+// +kubebuilder:validation:XValidation:rule="((has(self.envoyDeployment) && !has(self.envoyDaemonSet)) || (!has(self.envoyDeployment) && has(self.envoyDaemonSet))) || (!has(self.envoyDeployment) && !has(self.envoyDaemonSet))",message="only one of envoyDeployment or envoyDaemonSet can be specified"
+// +kubebuilder:validation:XValidation:rule="((has(self.envoyHpa) && !has(self.envoyDaemonSet)) || (!has(self.envoyHpa) && has(self.envoyDaemonSet))) || (!has(self.envoyHpa) && !has(self.envoyDaemonSet))",message="cannot use envoyHpa if envoyDaemonSet is used"
+//
 // EnvoyProxyKubernetesProvider defines configuration for the Kubernetes resource
 // provider.
 type EnvoyProxyKubernetesProvider struct {
@@ -228,6 +231,12 @@ type EnvoyProxyKubernetesProvider struct {
 	// +optional
 	EnvoyDeployment *KubernetesDeploymentSpec `json:"envoyDeployment,omitempty"`
 
+	// EnvoyDaemonSet defines the desired state of the Envoy daemonset resource.
+	// Disabled by default, a deployment resource is used instead to provision the Envoy Proxy fleet
+	//
+	// +optional
+	EnvoyDaemonSet *KubernetesDaemonSetSpec `json:"envoyDaemonSet,omitempty"`
+
 	// EnvoyService defines the desired state of the Envoy service resource.
 	// If unspecified, default settings for the managed Envoy service resource
 	// are applied.

api/v1alpha1/kubernetes_helpers.go

@@ -24,6 +24,13 @@ func DefaultKubernetesDeploymentStrategy() *appv1.DeploymentStrategy {
 	}
 }
 
+// DefaultKubernetesDaemonSetStrategy returns the default daemonset strategy settings.
+func DefaultKubernetesDaemonSetStrategy() *appv1.DaemonSetUpdateStrategy {
+	return &appv1.DaemonSetUpdateStrategy{
+		Type: appv1.RollingUpdateDaemonSetStrategyType,
+	}
+}
+
 // DefaultKubernetesContainerImage returns the default envoyproxy image.
 func DefaultKubernetesContainerImage(image string) *string {
 	return ptr.To(image)
@@ -38,6 +45,15 @@ func DefaultKubernetesDeployment(image string) *KubernetesDeploymentSpec {
 	}
 }
 
+// DefaultKubernetesDaemonSet returns a new DefaultKubernetesDaemonSet with default settings.
+func DefaultKubernetesDaemonSet(image string) *KubernetesDaemonSetSpec {
+	return &KubernetesDaemonSetSpec{
+		Strategy:  DefaultKubernetesDaemonSetStrategy(),
+		Pod:       DefaultKubernetesPod(),
+		Container: DefaultKubernetesContainer(image),
+	}
+}
+
 // DefaultKubernetesPod returns a new KubernetesPodSpec with default settings.
 func DefaultKubernetesPod() *KubernetesPodSpec {
 	return &KubernetesPodSpec{}
@@ -110,6 +126,29 @@ func (deployment *KubernetesDeploymentSpec) defaultKubernetesDeploymentSpec(imag
 	}
 }
 
+// defaultKubernetesDaemonSetSpec fill a default KubernetesDaemonSetSpec if unspecified.
+func (daemonset *KubernetesDaemonSetSpec) defaultKubernetesDaemonSetSpec(image string) {
+	if daemonset.Strategy == nil {
+		daemonset.Strategy = DefaultKubernetesDaemonSetStrategy()
+	}
+
+	if daemonset.Pod == nil {
+		daemonset.Pod = DefaultKubernetesPod()
+	}
+
+	if daemonset.Container == nil {
+		daemonset.Container = DefaultKubernetesContainer(image)
+	}
+
+	if daemonset.Container.Resources == nil {
+		daemonset.Container.Resources = DefaultResourceRequirements()
+	}
+
+	if daemonset.Container.Image == nil {
+		daemonset.Container.Image = DefaultKubernetesContainerImage(image)
+	}
+}
+
 // setDefault fill a default HorizontalPodAutoscalerSpec if unspecified
 func (hpa *KubernetesHorizontalPodAutoscalerSpec) setDefault() {
 	if len(hpa.Metrics) == 0 {
@@ -153,6 +192,42 @@ func (deployment *KubernetesDeploymentSpec) ApplyMergePatch(old *appv1.Deploymen
 	return &patchedDeployment, nil
 }
 
+// ApplyMergePatch applies a merge patch to a daemonset based on the merge type
+func (daemonset *KubernetesDaemonSetSpec) ApplyMergePatch(old *appv1.DaemonSet) (*appv1.DaemonSet, error) {
+	if daemonset.Patch == nil {
+		return old, nil
+	}
+
+	var patchedJSON []byte
+	var err error
+
+	// Serialize the current daemonset to JSON
+	originalJSON, err := json.Marshal(old)
+	if err != nil {
+		return nil, fmt.Errorf("error marshaling original daemonset: %w", err)
+	}
+
+	switch {
+	case daemonset.Patch.Type == nil || *daemonset.Patch.Type == StrategicMerge:
+		patchedJSON, err = strategicpatch.StrategicMergePatch(originalJSON, daemonset.Patch.Value.Raw, appv1.DaemonSet{})
+	case *daemonset.Patch.Type == JSONMerge:
+		patchedJSON, err = jsonpatch.MergePatch(originalJSON, daemonset.Patch.Value.Raw)
+	default:
+		return nil, fmt.Errorf("unsupported merge type: %s", *daemonset.Patch.Type)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("error applying merge patch: %w", err)
+	}
+
+	// Deserialize the patched JSON into a new daemonset object
+	var patchedDaemonSet appv1.DaemonSet
+	if err := json.Unmarshal(patchedJSON, &patchedDaemonSet); err != nil {
+		return nil, fmt.Errorf("error unmarshaling patched daemonset: %w", err)
+	}
+
+	return &patchedDaemonSet, nil
+}
+
 // ApplyMergePatch applies a merge patch to a service based on the merge type
 func (service *KubernetesServiceSpec) ApplyMergePatch(old *corev1.Service) (*corev1.Service, error) {
 	if service.Patch == nil {

api/v1alpha1/shared_types.go

@@ -93,6 +93,28 @@ type KubernetesDeploymentSpec struct {
 	// TODO: Expose config as use cases are better understood, e.g. labels.
 }
 
+// KubernetesDaemonsetSpec defines the desired state of the Kubernetes daemonset resource.
+type KubernetesDaemonSetSpec struct {
+	// Patch defines how to perform the patch operation to daemonset
+	//
+	// +optional
+	Patch *KubernetesPatchSpec `json:"patch,omitempty"`
+
+	// The daemonset strategy to use to replace existing pods with new ones.
+	// +optional
+	Strategy *appv1.DaemonSetUpdateStrategy `json:"strategy,omitempty"`
+
+	// Pod defines the desired specification of pod.
+	//
+	// +optional
+	Pod *KubernetesPodSpec `json:"pod,omitempty"`
+
+	// Container defines the desired specification of main container.
+	//
+	// +optional
+	Container *KubernetesContainerSpec `json:"container,omitempty"`
+}
+
 // KubernetesPodSpec defines the desired state of the Kubernetes pod resource.
 type KubernetesPodSpec struct {
 	// Annotations are the annotations that should be appended to the pods.