Merge pull request #556 from sttts/sttts-silently-ignore-conflicts

errors: add SilentlyRequeueOnConflicts

pkg/errors/reconcile.go

@@ -0,0 +1,49 @@
+/*
+Copyright 2023 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 errors
+
+import (
+	"context"
+
+	kerrors "k8s.io/apimachinery/pkg/api/errors"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+)
+
+// SilentlyRequeueOnConflict returns a requeue result and silently drops the
+// error if it is a Kubernetes conflict error from the optimistic concurrency
+// protocol.
+func SilentlyRequeueOnConflict(result reconcile.Result, err error) (reconcile.Result, error) {
+	if kerrors.IsConflict(Cause(err)) {
+		return reconcile.Result{Requeue: true}, nil
+	}
+	return result, err
+}
+
+// WithSilentRequeueOnConflict wraps a Reconciler and silently drops conflict
+// errors and requeues instead.
+func WithSilentRequeueOnConflict(r reconcile.Reconciler) reconcile.Reconciler {
+	return &silentlyRequeueOnConflict{Reconciler: r}
+}
+
+type silentlyRequeueOnConflict struct {
+	reconcile.Reconciler
+}
+
+func (r *silentlyRequeueOnConflict) Reconcile(ctx context.Context, req reconcile.Request) (reconcile.Result, error) {
+	result, err := r.Reconciler.Reconcile(ctx, req)
+	return SilentlyRequeueOnConflict(result, err)
+}

pkg/errors/reconcile_test.go

@@ -0,0 +1,99 @@
+/*
+Copyright 2023 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 errors
+
+import (
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+	kerrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+
+	"github.com/crossplane/crossplane-runtime/pkg/test"
+)
+
+func TestSilentlyRequeueOnConflict(t *testing.T) {
+	type args struct {
+		result reconcile.Result
+		err    error
+	}
+	type want struct {
+		result reconcile.Result
+		err    error
+	}
+	tests := []struct {
+		reason string
+		args   args
+		want   want
+	}{
+		{
+			reason: "nil error",
+			args: args{
+				result: reconcile.Result{RequeueAfter: time.Second},
+			},
+			want: want{
+				result: reconcile.Result{RequeueAfter: time.Second},
+			},
+		},
+		{
+			reason: "other error",
+			args: args{
+				result: reconcile.Result{RequeueAfter: time.Second},
+				err:    New("some other error"),
+			},
+			want: want{
+				result: reconcile.Result{RequeueAfter: time.Second},
+				err:    New("some other error"),
+			},
+		},
+		{
+			reason: "conflict error",
+			args: args{
+				result: reconcile.Result{RequeueAfter: time.Second},
+				err:    kerrors.NewConflict(schema.GroupResource{Group: "nature", Resource: "stones"}, "foo", New("nested error")),
+			},
+			want: want{
+				result: reconcile.Result{Requeue: true},
+			},
+		},
+		{
+			reason: "nested conflict error",
+			args: args{
+				result: reconcile.Result{RequeueAfter: time.Second},
+				err: Wrap(
+					kerrors.NewConflict(schema.GroupResource{Group: "nature", Resource: "stones"}, "foo", New("nested error")),
+					"outer error"),
+			},
+			want: want{
+				result: reconcile.Result{Requeue: true},
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.reason, func(t *testing.T) {
+			got, err := SilentlyRequeueOnConflict(tt.args.result, tt.args.err)
+			if diff := cmp.Diff(tt.want.err, err, test.EquateErrors()); diff != "" {
+				t.Errorf("\n%s\nIgnoreConflict(...): -want error, +got error:\n%s", tt.reason, diff)
+			}
+			if diff := cmp.Diff(tt.want.result, got); diff != "" {
+				t.Errorf("\n%s\nIgnoreConflict(...): -want result, +got result:\n%s", tt.reason, diff)
+			}
+		})
+	}
+}

pkg/reconciler/managed/reconciler.go

@@ -22,7 +22,6 @@ import (
 	"strings"
 	"time"
 
-	kerrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"sigs.k8s.io/controller-runtime/pkg/client"
@@ -714,19 +713,9 @@ func (r *Reconciler) Reconcile(ctx context.Context, req reconcile.Request) (resu
 	// NOTE(negz): This method is a well over our cyclomatic complexity goal.
 	// Be wary of adding additional complexity.
 
-	log := r.log.WithValues("request", req)
-
-	defer func() {
-		if kerrors.IsConflict(errors.Cause(err)) {
-			// conflict errors are transient in Kubernetes and completely normal.
-			// The right reaction is to requeue, but not record the object as error'ing
-			// or creating events.
-			log.Debug("Transient conflict error", "error", err)
-			result.Requeue = true
-			err = nil
-		}
-	}()
+	defer func() { result, err = errors.SilentlyRequeueOnConflict(result, err) }()
 
+	log := r.log.WithValues("request", req)
 	log.Debug("Reconciling")
 
 	ctx, cancel := context.WithTimeout(ctx, r.timeout+reconcileGracePeriod)