Allow adding reconciliation extensions (#9)

pkg/extensions/types.go

@@ -0,0 +1,12 @@
+package extensions
+
+import (
+	"context"
+	"github.com/go-logr/logr"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+)
+
+// ReconcileExtension is an arbitrary extension that can be implemented to run either before
+// or after the main Helm reconciliation action.
+// An error returned by a ReconcileExtension will cause the Reconcile to fail, unlike a hook error.
+type ReconcileExtension func(context.Context, *unstructured.Unstructured, logr.Logger) error

pkg/reconciler/reconciler.go

@@ -56,6 +56,7 @@ import (
 	"github.com/operator-framework/helm-operator-plugins/pkg/reconciler/internal/updater"
 	internalvalues "github.com/operator-framework/helm-operator-plugins/pkg/reconciler/internal/values"
 	"github.com/operator-framework/helm-operator-plugins/pkg/values"
+	"github.com/joelanford/helm-operator/pkg/extensions"
 )
 
 const uninstallFinalizer = "uninstall-helm-release"
@@ -70,6 +71,9 @@ type Reconciler struct {
 	preHooks           []hook.PreHook
 	postHooks          []hook.PostHook
 
+	preExtensions  []extensions.ReconcileExtension
+	postExtensions []extensions.ReconcileExtension
+
 	log                              logr.Logger
 	gvk                              *schema.GroupVersionKind
 	chrt                             *chart.Chart
@@ -423,6 +427,20 @@ func WithPreHook(h hook.PreHook) Option {
 	}
 }
 
+// WithPreExtension is an Option that configures the reconciler to run the given
+// extension before performing any reconciliation steps (including values translation).
+// An error returned from the extension will cause the reconciliation to fail.
+// This should be preferred to WithPreHook in most cases, except for when the logic
+// depends on the translated Helm values.
+// The extension will be invoked with the raw object state; meaning it needs to be careful
+// to check for existence of the deletionTimestamp field.
+func WithPreExtension(e extensions.ReconcileExtension) Option {
+	return func(r *Reconciler) error {
+		r.preExtensions = append(r.preExtensions, e)
+		return nil
+	}
+}
+
 // WithPostHook is an Option that configures the reconciler to run the given
 // PostHook just after performing any non-uninstall release actions.
 func WithPostHook(h hook.PostHook) Option {
@@ -432,6 +450,22 @@ func WithPostHook(h hook.PostHook) Option {
 	}
 }
 
+// WithPostExtension is an Option that configures the reconciler to run the given
+// extension after performing any reconciliation steps (including uninstall of the release,
+// but not removal of the finalizer).
+// An error returned from the extension will cause the reconciliation to fail, which might
+// prevent the finalizer from getting removed.
+// This should be preferred to WithPostHook in most cases, except for when the logic
+// depends on the translated Helm values.
+// The extension will be invoked with the raw object state; meaning it needs to be careful
+// to check for existence of the deletionTimestamp field.
+func WithPostExtension(e extensions.ReconcileExtension) Option {
+	return func(r *Reconciler) error {
+		r.postExtensions = append(r.postExtensions, e)
+		return nil
+	}
+}
+
 // WithValueTranslator is an Option that configures a function that translates a
 // custom resource to the values passed to Helm.
 // Use this if you need to customize the logic that translates your custom resource to Helm values.
@@ -566,6 +600,16 @@ func (r *Reconciler) Reconcile(ctx context.Context, req ctrl.Request) (res ctrl.
 	}
 	u.UpdateStatus(updater.EnsureCondition(conditions.Initialized(corev1.ConditionTrue, "", "")))
 
+	for _, ext := range r.preExtensions {
+		if err := ext(ctx, obj, r.log); err != nil {
+			u.UpdateStatus(
+				updater.EnsureCondition(conditions.Irreconcilable(corev1.ConditionTrue, conditions.ReasonReconcileError, err)),
+				updater.EnsureConditionUnknown(conditions.TypeReleaseFailed),
+			)
+			return ctrl.Result{}, err
+		}
+	}
+
 	if obj.GetDeletionTimestamp() != nil {
 		err := r.handleDeletion(ctx, actionClient, obj, log)
 		return ctrl.Result{}, err
@@ -625,6 +669,16 @@ func (r *Reconciler) Reconcile(ctx context.Context, req ctrl.Request) (res ctrl.
 		}
 	}
 
+	for _, ext := range r.postExtensions {
+		if err := ext(ctx, obj, r.log); err != nil {
+			u.UpdateStatus(
+				updater.EnsureCondition(conditions.Irreconcilable(corev1.ConditionTrue, conditions.ReasonReconcileError, err)),
+				updater.EnsureConditionUnknown(conditions.TypeReleaseFailed),
+			)
+			return ctrl.Result{}, err
+		}
+	}
+
 	ensureDeployedRelease(&u, rel)
 	u.UpdateStatus(
 		updater.EnsureCondition(conditions.ReleaseFailed(corev1.ConditionFalse, "", "")),
@@ -679,7 +733,7 @@ func (r *Reconciler) handleDeletion(ctx context.Context, actionClient helmclient
 				err = applyErr
 			}
 		}()
-		return r.doUninstall(actionClient, &uninstallUpdater, obj, log)
+		return r.doUninstall(ctx, actionClient, &uninstallUpdater, obj, log)
 	}(); err != nil {
 		return err
 	}
@@ -825,7 +879,7 @@ func (r *Reconciler) doReconcile(actionClient helmclient.ActionInterface, u *upd
 	return nil
 }
 
-func (r *Reconciler) doUninstall(actionClient helmclient.ActionInterface, u *updater.Updater, obj *unstructured.Unstructured, log logr.Logger) error {
+func (r *Reconciler) doUninstall(ctx context.Context, actionClient helmclient.ActionInterface, u *updater.Updater, obj *unstructured.Unstructured, log logr.Logger) error {
 	var opts []helmclient.UninstallOption
 	for name, annot := range r.uninstallAnnotations {
 		if v, ok := obj.GetAnnotations()[name]; ok {
@@ -850,6 +904,17 @@ func (r *Reconciler) doUninstall(actionClient helmclient.ActionInterface, u *upd
 			fmt.Println(diff.Generate(resp.Release.Manifest, ""))
 		}
 	}
+
+	for _, ext := range r.postExtensions {
+		if err := ext(ctx, obj, r.log); err != nil {
+			u.UpdateStatus(
+				updater.EnsureCondition(conditions.Irreconcilable(corev1.ConditionTrue, conditions.ReasonReconcileError, err)),
+				updater.EnsureConditionUnknown(conditions.TypeReleaseFailed),
+			)
+			return err
+		}
+	}
+
 	u.Update(updater.RemoveFinalizer(uninstallFinalizer))
 	u.UpdateStatus(
 		updater.EnsureCondition(conditions.ReleaseFailed(corev1.ConditionFalse, "", "")),