cleanerr: Clean errors for stable status

internal/controller/object/cleanerr.go

@@ -0,0 +1,37 @@
+package object
+
+import "regexp"
+
+// CleanErr masks pointers in err when printing the message.
+// errors.As and errors.Is can still find the original error.
+// If err is nil, CleanErr returns nil.
+func CleanErr(err error) error {
+	if err == nil {
+		return nil
+	}
+	return &cleanedError{cause: err}
+}
+
+type cleanedError struct {
+	cause error
+}
+
+func (w *cleanedError) Error() string { return cleanErrorMessage(w.cause) }
+func (w *cleanedError) Cause() error  { return w.cause }
+
+// Unwrap provides compatibility for Go 1.13 error chains.
+func (w *cleanedError) Unwrap() error { return w.cause }
+
+var pointerRegex = regexp.MustCompile(`\(0x[0-9a-f]{5,}\)`)
+
+// cleanErrorMessage returns the error reproducible error message for kubernetes errors by removing any pointers in the message.
+//
+// Given
+//
+//	cannot patch object: Job.batch "pi-1" is invalid: spec.template: Invalid value: core.PodTemplateSpec{... TerminationGracePeriodSeconds:(*int64)(0x4012805d98)...: field is immutable
+//
+// the pointer will be masked: TerminationGracePeriodSeconds:(*int64)(..ptr..)
+func cleanErrorMessage(err error) string {
+	oldString := err.Error()
+	return pointerRegex.ReplaceAllString(oldString, "(..ptr..)")
+}

internal/controller/object/cleanerr_test.go

@@ -0,0 +1,65 @@
+package object
+
+import (
+	"testing"
+
+	"github.com/pkg/errors"
+	kerrors "k8s.io/apimachinery/pkg/api/errors"
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func TestCleanWrap(t *testing.T) {
+	const (
+		messageWithoutPointer    = "this is 0123abc a normal error message (yeah)"
+		messageWithPointer       = "cannot patch object: Job.batch 'pi-1' is invalid: spec.template: Invalid value: core.PodTemplateSpec{... TerminationGracePeriodSeconds:(*int64)(0x4012805d98): field is immutable"
+		messageWithPointerMasked = "cannot patch object: Job.batch 'pi-1' is invalid: spec.template: Invalid value: core.PodTemplateSpec{... TerminationGracePeriodSeconds:(*int64)(..ptr..): field is immutable"
+	)
+	tests := []struct {
+		name string
+		in   error
+
+		check func(t *testing.T, err error)
+	}{
+		{
+			name: "nil is nil",
+			in:   nil,
+			check: func(t *testing.T, err error) {
+				if err != nil {
+					t.Errorf("expected nil error, got %+v", err)
+				}
+			},
+		},
+		{
+			name: "normal error preserved",
+			in:   errors.New(messageWithoutPointer),
+			check: func(t *testing.T, err error) {
+				if err.Error() != messageWithoutPointer {
+					t.Errorf("expected %q error, got %v", messageWithoutPointer, err.Error())
+				}
+			},
+		},
+		{
+			name: "pointer is masked",
+			in:   errors.New(messageWithPointer),
+			check: func(t *testing.T, err error) {
+				if err.Error() != messageWithPointerMasked {
+					t.Errorf("expected %q error, got %v", messageWithPointerMasked, err.Error())
+				}
+			},
+		},
+		{
+			name: "errors.As preseved and kubernetes compatibility",
+			in:   &kerrors.StatusError{ErrStatus: v1.Status{Reason: v1.StatusReasonAlreadyExists}},
+			check: func(t *testing.T, err error) {
+				if !kerrors.IsAlreadyExists(err) {
+					t.Error("expected kerrors.IsAlreadyExists, got false")
+				}
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tt.check(t, CleanErr(tt.in))
+		})
+	}
+}

internal/controller/object/object.go

@@ -296,7 +296,7 @@ func (c *external) Update(ctx context.Context, mg resource.Managed) (managed.Ext
 	})
 
 	if err := c.client.Apply(ctx, obj); err != nil {
-		return managed.ExternalUpdate{}, errors.Wrap(err, errApplyObject)
+		return managed.ExternalUpdate{}, errors.Wrap(CleanErr(err), errApplyObject)
 	}
 
 	return managed.ExternalUpdate{}, c.setObserved(cr, obj)