Generate common logic for krshaped resources (#1311)

* generate krshaped logic

* add logic to the tag

* Update injection/README.md

Co-authored-by: Matt Moore <mattmoor@vmware.com>

* move var to reconciler

Co-authored-by: Matt Moore <mattmoor@vmware.com>

apis/test/example/v1alpha1/foo_types.go

@@ -27,7 +27,7 @@ import (
 )
 
 // +genclient
-// +genreconciler
+// +genreconciler:krshapedlogic=true
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
 
 // Foo is for testing.

apis/test/pub/v1alpha1/bar_types.go

@@ -27,7 +27,7 @@ import (
 )
 
 // +genclient
-// +genreconciler:class=example.com/filter.class
+// +genreconciler:class=example.com/filter.class,krshapedlogic=true
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
 
 // Bar is for testing.

codegen/cmd/injection-gen/generators/packages.go

@@ -211,6 +211,15 @@ func isNonNamespaced(tags map[string]map[string]string) bool {
 	return has
 }
 
+func isKRShaped(tags map[string]map[string]string) bool {
+	vals, has := tags["genclient"]
+	if !has {
+		return false
+	}
+	shaped, _ := vals["krshapedlogic"]
+	return shaped == "true"
+}
+
 func vendorless(p string) string {
 	if pos := strings.LastIndex(p, "/vendor/"); pos != -1 {
 		return p[pos+len("/vendor/"):]
@@ -424,6 +433,7 @@ func reconcilerPackages(basePackage string, groupPkgName string, gv clientgentyp
 		extracted := extractCommentTags(t)
 		reconcilerClass, hasReconcilerClass := extractReconcilerClassTag(extracted)
 		nonNamespaced := isNonNamespaced(extracted)
+		isKRShaped := isKRShaped(extracted)
 
 		packagePath := filepath.Join(packagePath, strings.ToLower(t.Name.Name))
 
@@ -512,6 +522,7 @@ func reconcilerPackages(basePackage string, groupPkgName string, gv clientgentyp
 					reconcilerClass:    reconcilerClass,
 					hasReconcilerClass: hasReconcilerClass,
 					nonNamespaced:      nonNamespaced,
+					isKRShaped:         isKRShaped,
 				})
 
 				return generators

codegen/cmd/injection-gen/generators/reconciler_reconciler.go

@@ -40,6 +40,7 @@ type reconcilerReconcilerGenerator struct {
 	reconcilerClass    string
 	hasReconcilerClass bool
 	nonNamespaced      bool
+	isKRShaped         bool
 
 	groupGoName  string
 	groupVersion clientgentypes.GroupVersion
@@ -74,6 +75,7 @@ func (g *reconcilerReconcilerGenerator) GenerateType(c *generator.Context, t *ty
 		"version":       namer.IC(g.groupVersion.Version.String()),
 		"class":         g.reconcilerClass,
 		"hasClass":      g.hasReconcilerClass,
+		"isKRShaped":    g.isKRShaped,
 		"nonNamespaced": g.nonNamespaced,
 		"controllerImpl": c.Universe.Type(types.Name{
 			Package: "knative.dev/pkg/controller",
@@ -309,9 +311,17 @@ func (r *reconcilerImpl) Reconcile(ctx {{.contextContext|raw}}, key string) erro
 			logger.Warnw("Failed to set finalizers", zap.Error(err))
 		}
 
+		{{if .isKRShaped}}
+		reconciler.PreProcessReconcile(ctx, resource)
+		{{end}}
+
 		// Reconcile this copy of the resource and then write back any status
 		// updates regardless of whether the reconciliation errored out.
 		reconcileEvent = r.reconciler.ReconcileKind(ctx, resource)
+
+		{{if .isKRShaped}}
+		reconciler.PostProcessReconcile(ctx, resource)
+		{{end}}
 	} else if fin, ok := r.reconciler.(Finalizer); ok {
 		// Append the target method to the logger.
 		logger = logger.With(zap.String("targetMethod", "FinalizeKind"))

injection/README.md

@@ -452,6 +452,28 @@ value of the `<key>` annotation on a resource must match the value provided to
 `NewImpl` (or `NewReconcile`) for `ReconcileKind` or `FinalizeKind` to be called
 for that resource.
 
+#### Annotation based common logic
+
+**krshaped=true may become the default if omitted in the future**
+
+Reconcilers can handle common logic for resources that conform to the KRShaped
+interface. This allows the generated code to automatically increment
+ObservedGeneration.
+
+```go
+// +genreconciler:krshapedlogic=true
+```
+
+Setting this annotation will emit the following in the generated reconciler.
+
+```go
+reconciler.PreProcessReconcile(ctx, resource)
+
+reconcileEvent = r.reconciler.ReconcileKind(ctx, resource)
+
+reconciler.PostProcessReconcile(ctx, resource)
+```
+
 #### Stubs
 
 To get started, or to use as reference. It is intended to be copied out of the