Added IsTransient function to check if an error is transient or not (#309)

Author: chatton

pkg/controller/mongodb/mongodb_status_options.go

@@ -2,6 +2,7 @@ package mongodb
 
 import (
 	mdbv1 "github.com/mongodb/mongodb-kubernetes-operator/pkg/apis/mongodb/v1"
+	"github.com/mongodb/mongodb-kubernetes-operator/pkg/util/apierrors"
 	"github.com/mongodb/mongodb-kubernetes-operator/pkg/util/result"
 	"go.uber.org/zap"
 
@@ -112,6 +113,10 @@ func (o *optionBuilder) withStatefulSetReplicas(members int) *optionBuilder {
 }
 
 func (o *optionBuilder) withMessage(severityLevel severity, msg string) *optionBuilder {
+	if apierrors.IsTransientMessage(msg) {
+		severityLevel = Debug
+		msg = ""
+	}
 	o.options = append(o.options, messageOption{
 		message: message{
 			messageString: msg,

pkg/util/apierrors/apierrors.go

@@ -0,0 +1,17 @@
+package apierrors
+
+import "strings"
+
+// objectModifiedText is an error indicating that we are trying to update a resource that has since been updated.
+// in this case we just want to retry but not log it as an error.
+var objectModifiedText = "the object has been modified; please apply your changes to the latest version and try again"
+
+// IsTransientError returns a boolean indicating if a given error is transient.
+func IsTransientError(err error) bool {
+	return IsTransientMessage(err.Error())
+}
+
+// IsTransientMessage returns a boolean indicating if a given error message is transient.
+func IsTransientMessage(msg string) bool {
+	return strings.Contains(strings.ToLower(msg), objectModifiedText)
+}

pkg/util/apierrors/apierrors_test.go

@@ -0,0 +1,37 @@
+package apierrors
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestIsTransientError(t *testing.T) {
+	tests := []struct {
+		name string
+		err  error
+		want bool
+	}{
+		{
+			"Test Transient capitalised error",
+			fmt.Errorf("Error updating the status of the MongoDB resource: Operation cannot be fulfilled on mongodbcommunity.mongodb.com \"mdb0\": The object has been modified; please apply your changes to the latest version and try again"),
+			true,
+		},
+		{
+			"Test Transient lower case error",
+			fmt.Errorf("error updating the status of the MongoDB resource: Operation cannot be fulfilled on mongodbcommunity.mongodb.com \"mdb0\": the object has been modified; please apply your changes to the latest version and try again"),
+			true,
+		},
+		{
+			"Test Not Transient Error",
+			fmt.Errorf(" error found deployments.extensions \"default\" not found"),
+			false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := IsTransientError(tt.err); got != tt.want {
+				t.Errorf("IsTransientError() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}