Merge pull request #326 from muvaf/webhook-chains

Add validator and mutator chain executors to be used by provider webhooks

pkg/webhook/mutator.go

@@ -0,0 +1,65 @@
+/*
+Copyright 2022 The Crossplane Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package webhook
+
+import (
+	"context"
+
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+// WithMutationFns allows you to initiate the mutator with given list of mutator
+// functions.
+func WithMutationFns(fns ...MutateFn) MutatorOption {
+	return func(m *Mutator) {
+		m.MutationChain = fns
+	}
+}
+
+// MutatorOption configures given Mutator.
+type MutatorOption func(*Mutator)
+
+// MutateFn is a single mutating function that can be used by Mutator.
+type MutateFn func(ctx context.Context, obj runtime.Object) error
+
+// NewMutator returns a new instance of Mutator that can be used as CustomDefaulter.
+func NewMutator(opts ...MutatorOption) *Mutator {
+	m := &Mutator{
+		MutationChain: []MutateFn{},
+	}
+	for _, f := range opts {
+		f(m)
+	}
+	return m
+}
+
+// Mutator satisfies CustomDefaulter interface with an ordered MutateFn list.
+type Mutator struct {
+	MutationChain []MutateFn
+}
+
+// Default executes the MutatorFns in given order. Its name might sound misleading
+// since defaulting seems to be the first use case used by controller-runtime
+// but MutatorFns can make any changes on given resource.
+func (m *Mutator) Default(ctx context.Context, obj runtime.Object) error {
+	for _, f := range m.MutationChain {
+		if err := f(ctx, obj); err != nil {
+			return err
+		}
+	}
+	return nil
+}

pkg/webhook/mutator_test.go

@@ -0,0 +1,80 @@
+/*
+Copyright 2022 The Crossplane Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package webhook
+
+import (
+	"context"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"k8s.io/apimachinery/pkg/runtime"
+	"sigs.k8s.io/controller-runtime/pkg/webhook"
+
+	"github.com/crossplane/crossplane-runtime/pkg/test"
+)
+
+// Mutator has to satisfy CustomDefaulter interface so that it can be used by
+// controller-runtime Manager.
+var _ webhook.CustomDefaulter = &Mutator{}
+
+func TestDefault(t *testing.T) {
+	type args struct {
+		obj runtime.Object
+		fns []MutateFn
+	}
+	type want struct {
+		err error
+	}
+	cases := map[string]struct {
+		reason string
+		args
+		want
+	}{
+		"Success": {
+			reason: "Functions without errors should be executed successfully",
+			args: args{
+				fns: []MutateFn{
+					func(_ context.Context, _ runtime.Object) error {
+						return nil
+					},
+				},
+			},
+		},
+		"Failure": {
+			reason: "Functions with errors should return with error",
+			args: args{
+				fns: []MutateFn{
+					func(_ context.Context, _ runtime.Object) error {
+						return errBoom
+					},
+				},
+			},
+			want: want{
+				err: errBoom,
+			},
+		},
+	}
+	for name, tc := range cases {
+		t.Run(name, func(t *testing.T) {
+			v := NewMutator(WithMutationFns(tc.fns...))
+			err := v.Default(context.TODO(), tc.args.obj)
+			if diff := cmp.Diff(tc.want.err, err, test.EquateErrors()); diff != "" {
+				t.Errorf("\n%s\nDefault(...): -want, +got\n%s\n", tc.reason, diff)
+			}
+		})
+	}
+}

pkg/webhook/validator.go

@@ -0,0 +1,109 @@
+/*
+Copyright 2022 The Crossplane Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package webhook
+
+import (
+	"context"
+
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+// WithValidateCreationFns initializes the Validator with given set of creation
+// validation functions.
+func WithValidateCreationFns(fns ...ValidateCreateFn) ValidatorOption {
+	return func(v *Validator) {
+		v.CreationChain = fns
+	}
+}
+
+// WithValidateUpdateFns initializes the Validator with given set of update
+// validation functions.
+func WithValidateUpdateFns(fns ...ValidateUpdateFn) ValidatorOption {
+	return func(v *Validator) {
+		v.UpdateChain = fns
+	}
+}
+
+// WithValidateDeletionFns initializes the Validator with given set of deletion
+// validation functions.
+func WithValidateDeletionFns(fns ...ValidateDeleteFn) ValidatorOption {
+	return func(v *Validator) {
+		v.DeletionChain = fns
+	}
+}
+
+// ValidatorOption allows you to configure given Validator.
+type ValidatorOption func(*Validator)
+
+// ValidateCreateFn is function type for creation validation.
+type ValidateCreateFn func(ctx context.Context, obj runtime.Object) error
+
+// ValidateUpdateFn is function type for update validation.
+type ValidateUpdateFn func(ctx context.Context, oldObj, newObj runtime.Object) error
+
+// ValidateDeleteFn is function type for deletion validation.
+type ValidateDeleteFn func(ctx context.Context, obj runtime.Object) error
+
+// NewValidator returns a new Validator with no-op defaults.
+func NewValidator(opts ...ValidatorOption) *Validator {
+	vc := &Validator{
+		CreationChain: []ValidateCreateFn{},
+		UpdateChain:   []ValidateUpdateFn{},
+		DeletionChain: []ValidateDeleteFn{},
+	}
+	for _, f := range opts {
+		f(vc)
+	}
+	return vc
+}
+
+// Validator runs the given validation chains in order.
+type Validator struct {
+	CreationChain []ValidateCreateFn
+	UpdateChain   []ValidateUpdateFn
+	DeletionChain []ValidateDeleteFn
+}
+
+// ValidateCreate runs functions in creation chain in order.
+func (vc *Validator) ValidateCreate(ctx context.Context, obj runtime.Object) error {
+	for _, f := range vc.CreationChain {
+		if err := f(ctx, obj); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// ValidateUpdate runs functions in update chain in order.
+func (vc *Validator) ValidateUpdate(ctx context.Context, oldObj, newObj runtime.Object) error {
+	for _, f := range vc.UpdateChain {
+		if err := f(ctx, oldObj, newObj); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// ValidateDelete runs functions in deletion chain in order.
+func (vc *Validator) ValidateDelete(ctx context.Context, obj runtime.Object) error {
+	for _, f := range vc.DeletionChain {
+		if err := f(ctx, obj); err != nil {
+			return err
+		}
+	}
+	return nil
+}