Merge pull request #351 from aruiz14/v1-generating-handlers-unique-apply

[v1.1] Allow GeneratingHandlers to skip Apply if resource version didn't change

go.mod

@@ -5,6 +5,7 @@ go 1.19
 require (
 	github.com/evanphx/json-patch v4.12.0+incompatible
 	github.com/ghodss/yaml v1.0.0
+	github.com/golang/mock v1.6.0
 	github.com/moby/locker v1.0.1
 	github.com/pkg/errors v0.9.1
 	github.com/rancher/lasso v0.0.0-20221227210133-6ea88ca2fbcc

go.sum

@@ -194,6 +194,7 @@ github.com/golang/mock v1.4.3/go.mod h1:UOMv5ysSaYNkG+OFQykRIcU/QvvxJf3p21QfJ2Bt
 github.com/golang/mock v1.4.4/go.mod h1:l3mdAwkq5BuhzHwde/uurv3sEJeZMXNpwsxVWU71h+4=
 github.com/golang/mock v1.5.0/go.mod h1:CWnOUgYIOo4TcNZ0wHX3YZCqsaM1I1Jvs6v3mP3KVu8=
 github.com/golang/mock v1.6.0 h1:ErTB+efbowRARo13NNdxyJji2egdxLGQhRaY+DUumQc=
+github.com/golang/mock v1.6.0/go.mod h1:p6yTPP+5HYm5mzsMV8JkE6ZKdX+/wYM6Hr+LicevLPs=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
@@ -805,6 +806,7 @@ golang.org/x/tools v0.0.0-20201224043029-2b0845dc783e/go.mod h1:emZCQorbCU4vsT4f
 golang.org/x/tools v0.0.0-20210105154028-b0ab187a4818/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/tools v0.0.0-20210106214847-113979e3529a/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
+golang.org/x/tools v0.1.1/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/tools v0.1.2/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/tools v0.6.0 h1:BOw41kyTf3PuCW1pVQf8+Cyg8pMlkYB1oo9iJ6D/lKM=
 golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=

pkg/apply/fake/apply.go

@@ -14,18 +14,19 @@ var _ apply.Apply = (*FakeApply)(nil)
 
 type FakeApply struct {
 	Objects []*objectset.ObjectSet
+	Count   int
 }
 
 func (f *FakeApply) Apply(set *objectset.ObjectSet) error {
 	f.Objects = append(f.Objects, set)
+	f.Count++
 	return nil
 }
 
 func (f *FakeApply) ApplyObjects(objs ...runtime.Object) error {
 	os := objectset.NewObjectSet()
 	os.Add(objs...)
-	f.Objects = append(f.Objects, os)
-	return nil
+	return f.Apply(os)
 }
 
 func (f *FakeApply) WithCacheTypes(igs ...apply.InformerGetter) apply.Apply {

pkg/controller-gen/generators/type_go.go

@@ -313,10 +313,14 @@ func (c *{{.lowerName}}Cache) GetByIndex(indexName, key string) (result []*{{.ve
 }
 
 {{ if .hasStatus -}}
+// {{.type}}StatusHandler is executed for every added or modified {{.type}}. Should return the new status to be updated
 type {{.type}}StatusHandler func(obj *{{.version}}.{{.type}}, status {{.version}}.{{.statusType}}) ({{.version}}.{{.statusType}}, error)
 
+// {{.type}}GeneratingHandler is the top-level handler that is executed for every {{.type}} event. It extends {{.type}}StatusHandler by a returning a slice of child objects to be passed to apply.Apply
 type {{.type}}GeneratingHandler func(obj *{{.version}}.{{.type}}, status {{.version}}.{{.statusType}}) ([]runtime.Object, {{.version}}.{{.statusType}}, error)
 
+// Register{{.type}}StatusHandler configures a {{.type}}Controller to execute a {{.type}}StatusHandler for every events observed.
+// If a non-empty condition is provided, it will be updated in the status conditions for every handler execution
 func Register{{.type}}StatusHandler(ctx context.Context, controller {{.type}}Controller, condition condition.Cond, name string, handler {{.type}}StatusHandler) {
 	statusHandler := &{{.lowerName}}StatusHandler{
 		client:    controller,
@@ -326,6 +330,8 @@ func Register{{.type}}StatusHandler(ctx context.Context, controller {{.type}}Con
 	controller.AddGenericHandler(ctx, name, From{{.type}}HandlerToHandler(statusHandler.sync))
 }
 
+// Register{{.type}}GeneratingHandler configures a {{.type}}Controller to execute a {{.type}}GeneratingHandler for every events observed, passing the returned objects to the provided apply.Apply.
+// If a non-empty condition is provided, it will be updated in the status conditions for every handler execution
 func Register{{.type}}GeneratingHandler(ctx context.Context, controller {{.type}}Controller, apply apply.Apply,
 	condition condition.Cond, name string, handler {{.type}}GeneratingHandler, opts *generic.GeneratingHandlerOptions) {
 	statusHandler := &{{.lowerName}}GeneratingHandler{
@@ -347,6 +353,7 @@ type {{.lowerName}}StatusHandler struct {
 	handler   {{.type}}StatusHandler
 }
 
+// sync is executed on every resource addition or modification. Executes the configured handlers and sends the updated status to the Kubernetes API
 func (a *{{.lowerName}}StatusHandler) sync(key string, obj *{{.version}}.{{.type}}) (*{{.version}}.{{.type}}, error) {
 	if obj == nil {
 		return obj, nil
@@ -388,12 +395,14 @@ func (a *{{.lowerName}}StatusHandler) sync(key string, obj *{{.version}}.{{.type
 
 type {{.lowerName}}GeneratingHandler struct {
 	{{.type}}GeneratingHandler
-	apply apply.Apply
-	opts  generic.GeneratingHandlerOptions
-	gvk   schema.GroupVersionKind
-	name  string
+	apply      apply.Apply
+	opts       generic.GeneratingHandlerOptions
+	gvk        schema.GroupVersionKind
+	name       string
+	seen       sync.Map
 }
 
+// Remove handles the observed deletion of a resource, cascade deleting every associated resource previously applied
 func (a *{{.lowerName}}GeneratingHandler) Remove(key string, obj *{{.version}}.{{.type}}) (*{{.version}}.{{.type}}, error) {
 	if obj != nil {
 		return obj, nil
@@ -403,12 +412,17 @@ func (a *{{.lowerName}}GeneratingHandler) Remove(key string, obj *{{.version}}.{
 	obj.Namespace, obj.Name = kv.RSplit(key, "/")
 	obj.SetGroupVersionKind(a.gvk)
 
+	if a.opts.UniqueApplyForResourceVersion {
+		a.seen.Delete(key)
+	}
+
 	return nil, generic.ConfigureApplyForObject(a.apply, obj, &a.opts).
 		WithOwner(obj).
 		WithSetID(a.name).
 		ApplyObjects()
 }
 
+// Handle executes the configured {{.type}}GeneratingHandler and pass the resulting objects to apply.Apply, finally returning the new status of the resource
 func (a *{{.lowerName}}GeneratingHandler) Handle(obj *{{.version}}.{{.type}}, status {{.version}}.{{.statusType}}) ({{.version}}.{{.statusType}}, error) {
 	if !obj.DeletionTimestamp.IsZero() {
 		return status, nil
@@ -418,11 +432,43 @@ func (a *{{.lowerName}}GeneratingHandler) Handle(obj *{{.version}}.{{.type}}, st
 	if err != nil {
 		return newStatus, err
 	}
+	if !a.isNewResourceVersion(obj) {
+	    return newStatus, nil
+	}
 
-	return newStatus, generic.ConfigureApplyForObject(a.apply, obj, &a.opts).
+	err = generic.ConfigureApplyForObject(a.apply, obj, &a.opts).
 		WithOwner(obj).
 		WithSetID(a.name).
 		ApplyObjects(objs...)
+	if err != nil {
+		return newStatus, err
+	}
+	a.storeResourceVersion(obj)
+	return newStatus, nil
+}
+
+// isNewResourceVersion detects if a specific resource version was already successfully processed. 
+// Only used if UniqueApplyForResourceVersion is set in generic.GeneratingHandlerOptions
+func (a *{{.lowerName}}GeneratingHandler) isNewResourceVersion(obj *{{.version}}.{{.type}}) bool {
+	if !a.opts.UniqueApplyForResourceVersion {
+		return true
+	}
+
+	// Apply once per resource version
+	key := obj.Namespace + "/" + obj.Name
+	previous, ok := a.seen.Load(key)
+	return !ok || previous != obj.ResourceVersion
+}
+
+// storeResourceVersion keeps track of the latest resource version of an object for which Apply was executed
+// Only used if UniqueApplyForResourceVersion is set in generic.GeneratingHandlerOptions
+func (a *{{.lowerName}}GeneratingHandler) storeResourceVersion(obj *{{.version}}.{{.type}}) {
+	if !a.opts.UniqueApplyForResourceVersion {
+		return
+	}
+
+	key := obj.Namespace + "/" + obj.Name
+	a.seen.Store(key, obj.ResourceVersion)
 }
 {{- end }}
 `

pkg/controller-gen/generators/util.go

@@ -11,6 +11,7 @@ import (
 var (
 	Imports = []string{
 		"context",
+		"sync",
 		"time",
 		"k8s.io/client-go/rest",
 		"github.com/rancher/lasso/pkg/client",