api: add `PersistentClient` flag to allow control

This adds a `PersistentClient` flag which should be consumed by the
controller while initializing the Kubernetes client used by Helm
actions.

This to allow the controller to work with certain charts which do
require a client which does not persist, as they create Custom Resource
Definitions on demand during e.g. install, which then later aren't
observed by Helm as it does not reset the REST mapper between successive
action steps.

Signed-off-by: Hidde Beydals <hidde@hhh.computer>

api/v2beta1/helmrelease_types.go

@@ -137,6 +137,21 @@ type HelmReleaseSpec struct {
 	// +optional
 	ServiceAccountName string `json:"serviceAccountName,omitempty"`
 
+	// PersistentClient tells the controller to use a persistent Kubernetes
+	// client for this release. When enabled, the client will be reused for the
+	// duration of the reconciliation, instead of being created and destroyed
+	// for each (step of a) Helm action.
+	//
+	// This can improve performance, but may cause issues with some Helm charts
+	// that for example do create Custom Resource Definitions during installation
+	// outside Helm's CRD lifecycle hooks, which are then not observed to be
+	// available by e.g. post-install hooks.
+	//
+	// If not set, it defaults to true.
+	//
+	// +optional
+	PersistentClient *bool `json:"persistentClient,omitempty"`
+
 	// Install holds the configuration for Helm install actions for this HelmRelease.
 	// +optional
 	Install *Install `json:"install,omitempty"`
@@ -1039,6 +1054,15 @@ func (in HelmRelease) GetMaxHistory() int {
 	return *in.Spec.MaxHistory
 }
 
+// UsePersistentClient returns the configured PersistentClient, or the default
+// of true.
+func (in HelmRelease) UsePersistentClient() bool {
+	if in.Spec.PersistentClient == nil {
+		return true
+	}
+	return *in.Spec.PersistentClient
+}
+
 // GetDependsOn returns the list of dependencies across-namespaces.
 func (in HelmRelease) GetDependsOn() []meta.NamespacedObjectReference {
 	return in.Spec.DependsOn

api/v2beta1/zz_generated.deepcopy.go

@@ -225,6 +225,11 @@ func (in *HelmReleaseSpec) DeepCopyInto(out *HelmReleaseSpec) {
 		*out = new(int)
 		**out = **in
 	}
+	if in.PersistentClient != nil {
+		in, out := &in.PersistentClient, &out.PersistentClient
+		*out = new(bool)
+		**out = **in
+	}
 	if in.Install != nil {
 		in, out := &in.Install, &out.Install
 		*out = new(Install)

config/crd/bases/helm.toolkit.fluxcd.io_helmreleases.yaml

@@ -322,6 +322,17 @@ spec:
                   this HelmRelease. Use '0' for an unlimited number of revisions;
                   defaults to '10'.
                 type: integer
+              persistentClient:
+                description: "PersistentClient tells the controller to use a persistent
+                  Kubernetes client for this release. When enabled, the client will
+                  be reused for the duration of the reconciliation, instead of being
+                  created and destroyed for each (step of a) Helm action. \n This
+                  can improve performance, but may cause issues with some Helm charts
+                  that for example do create Custom Resource Definitions during installation
+                  outside Helm's CRD lifecycle hooks, which are then not observed
+                  to be available by e.g. post-install hooks. \n If not set, it defaults
+                  to true."
+                type: boolean
               postRenderers:
                 description: PostRenderers holds an array of Helm PostRenderers, which
                   will be applied in order of their definition.

docs/api/helmrelease.md

@@ -226,6 +226,26 @@ when reconciling this HelmRelease.</p>
 </tr>
 <tr>
 <td>
+<code>persistentClient</code><br>
+<em>
+bool
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>PersistentClient tells the controller to use a persistent Kubernetes
+client for this release. When enabled, the client will be reused for the
+duration of the reconciliation, instead of being created and destroyed
+for each (step of a) Helm action.</p>
+<p>This can improve performance, but may cause issues with some Helm charts
+that for example do create Custom Resource Definitions during installation
+outside Helm&rsquo;s CRD lifecycle hooks, which are then not observed to be
+available by e.g. post-install hooks.</p>
+<p>If not set, it defaults to true.</p>
+</td>
+</tr>
+<tr>
+<td>
 <code>install</code><br>
 <em>
 <a href="#helm.toolkit.fluxcd.io/v2beta1.Install">
@@ -1015,6 +1035,26 @@ when reconciling this HelmRelease.</p>
 </tr>
 <tr>
 <td>
+<code>persistentClient</code><br>
+<em>
+bool
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>PersistentClient tells the controller to use a persistent Kubernetes
+client for this release. When enabled, the client will be reused for the
+duration of the reconciliation, instead of being created and destroyed
+for each (step of a) Helm action.</p>
+<p>This can improve performance, but may cause issues with some Helm charts
+that for example do create Custom Resource Definitions during installation
+outside Helm&rsquo;s CRD lifecycle hooks, which are then not observed to be
+available by e.g. post-install hooks.</p>
+<p>If not set, it defaults to true.</p>
+</td>
+</tr>
+<tr>
+<td>
 <code>install</code><br>
 <em>
 <a href="#helm.toolkit.fluxcd.io/v2beta1.Install">

docs/spec/v2beta1/helmreleases.md

@@ -66,6 +66,21 @@ type HelmReleaseSpec struct {
 	// +optional
 	MaxHistory *int `json:"maxHistory,omitempty"`
 
+	// PersistentClient tells the controller to use a persistent Kubernetes
+	// client for this release. When enabled, the client will be reused for the
+	// duration of the reconciliation, instead of being created and destroyed
+	// for each (step of a) Helm action.
+	//
+	// This can improve performance, but may cause issues with some Helm charts
+	// that for example do create Custom Resource Definitions during installation
+	// outside Helm's CRD lifecycle hooks, which are then not observed to be
+	// available by e.g. post-install hooks.
+	//
+	// If not set, it defaults to true.
+	//
+	// +optional
+	PersistentClient *bool `json:"persistentClient,omitempty"`
+
 	// Install holds the configuration for Helm install actions for this HelmRelease.
 	// +optional
 	Install *Install `json:"install,omitempty"`