fix(gateway): circuit breaker should check if upstream exists before creating

gateway/internal/features/feature/circuit_breaker.go

@@ -7,6 +7,7 @@
 import (
 	"context"
 	"fmt"
+
 	"github.com/go-logr/logr"
 	"github.com/pkg/errors"
 	"github.com/telekom/controlplane/common/pkg/util/contextutil"
@@ -101,7 +102,7 @@
 
 func isDeleteScenario(route *gatewayv1.Route) bool {
 	// completely removed or turned to false
 	if (route.Spec.Traffic.CircuitBreaker != nil && route.Spec.Traffic.CircuitBreaker.Enabled == false) && route.GetUpstreamId() != "" {
 		return true
 	} else {
 		return false
@@ -171,7 +172,7 @@
 	targetsName := routeName
 	targetsTarget := DefaultTargetsTarget
 	targetsWeight := 100
-	targetsBody := kong.CreateTargetForUpstreamJSONRequestBody{
+	targetsBody := kong.UpsertTargetForUpstreamJSONRequestBody{
 		Tags: &[]string{
 			client.BuildTag("env", contextutil.EnvFromContextOrDie(ctx)),
 			client.BuildTag("targets", targetsName),
@@ -181,13 +182,13 @@
 		Weight: &targetsWeight,
 	}
 
-	// this is a special case with the kong admin API - this endpoint /upstreams/:upstreamName/targets actually accepts multiple POST requests, so this is not a mistake
-	targetsResponse, err := kongAdminApi.CreateTargetForUpstreamWithResponse(ctx, upstreamName, targetsBody)
+	// Use upsert (PUT) instead of create (POST) to handle re-reconciliation gracefully
+	targetsResponse, err := kongAdminApi.UpsertTargetForUpstreamWithResponse(ctx, upstreamName, targetsTarget, targetsBody)
 	if err != nil {
-		return errors.Wrap(err, "failed to create targets for upstream")
+		return errors.Wrap(err, "failed to upsert targets for upstream")
 	}
-	if err := client.CheckStatusCode(targetsResponse, 200, 201); err != nil {
-		return errors.Wrap(fmt.Errorf("error body from kong admin api: %s", string(targetsResponse.Body)), "failed to create targets for upstream")
+	if err := client.CheckStatusCode(targetsResponse, 200); err != nil {
+		return errors.Wrap(fmt.Errorf("error body from kong admin api: %s", string(targetsResponse.Body)), "failed to upsert targets for upstream")
 	}
 	route.SetTargetsId(*targetsResponse.JSON200.Id)
 

gateway/internal/features/feature/circuit_breaker_test.go

@@ -6,12 +6,13 @@ package feature_test
 
 import (
 	"context"
+	"net/http"
+
 	"github.com/telekom/controlplane/common/pkg/util/contextutil"
 	"github.com/telekom/controlplane/gateway/internal/features/feature/config"
 	kong "github.com/telekom/controlplane/gateway/pkg/kong/api"
 	"github.com/telekom/controlplane/gateway/pkg/kong/client/mock"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"net/http"
 
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
@@ -155,25 +156,27 @@ var _ = Describe("CircuitBreakerFeature", func() {
 				}
 				mockKongAdminApi.EXPECT().UpsertUpstreamWithResponse(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).DoAndReturn(upsertUpstreamWithResponse_func).Times(1)
 
-				// mock CreateTargetForUpstreamWithResponse
-				var createTargetForUpstreamWithResponse_upstreamNameArg string
-				var createTargetForUpstreamWithResponse_targetBodyArg kong.CreateTargetForUpstreamJSONRequestBody
+				// mock UpsertTargetForUpstreamWithResponse
+				var upsertTargetForUpstreamWithResponse_upstreamNameArg string
+				var upsertTargetForUpstreamWithResponse_targetIdArg string
+				var upsertTargetForUpstreamWithResponse_targetBodyArg kong.UpsertTargetForUpstreamJSONRequestBody
 
-				createTargetForUpstreamWithResponse_func := func(_ context.Context, upstreamName string, targetsBody kong.CreateTargetForUpstreamJSONRequestBody, _ ...kong.RequestEditorFn) (*kong.CreateTargetForUpstreamResponse, error) {
-					createTargetForUpstreamWithResponse_upstreamNameArg = upstreamName
-					createTargetForUpstreamWithResponse_targetBodyArg = targetsBody
+				upsertTargetForUpstreamWithResponse_func := func(_ context.Context, upstreamName string, targetIdOrTarget string, targetsBody kong.UpsertTargetForUpstreamJSONRequestBody, _ ...kong.RequestEditorFn) (*kong.UpsertTargetForUpstreamResponse, error) {
+					upsertTargetForUpstreamWithResponse_upstreamNameArg = upstreamName
+					upsertTargetForUpstreamWithResponse_targetIdArg = targetIdOrTarget
+					upsertTargetForUpstreamWithResponse_targetBodyArg = targetsBody
 
-					createTargetForUpstreamResponseId := "kong_target_response_id"
-					return &kong.CreateTargetForUpstreamResponse{
+					upsertTargetForUpstreamResponseId := "kong_target_response_id"
+					return &kong.UpsertTargetForUpstreamResponse{
 						HTTPResponse: &http.Response{
 							StatusCode: 200,
 						},
 						JSON200: &kong.Target{
-							Id: &createTargetForUpstreamResponseId,
+							Id: &upsertTargetForUpstreamResponseId,
 						},
 					}, nil
 				}
-				mockKongAdminApi.EXPECT().CreateTargetForUpstreamWithResponse(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).DoAndReturn(createTargetForUpstreamWithResponse_func).Times(1)
+				mockKongAdminApi.EXPECT().UpsertTargetForUpstreamWithResponse(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).DoAndReturn(upsertTargetForUpstreamWithResponse_func).Times(1)
 
 				// Execute
 				err := feature.InstanceCircuitBreakerFeature.Apply(ctx, mockFeatureBuilder)
@@ -195,10 +198,11 @@ var _ = Describe("CircuitBreakerFeature", func() {
 				Expect(upsertUpstreamWithResponse_upstreamBodyArg).To(Equal(*expectedUpstreamBody))
 				Expect(route.GetUpstreamId()).To(Equal("kong_upstream_response_id"))
 
-				Expect(createTargetForUpstreamWithResponse_upstreamNameArg).To(Equal("test-route-name"))
+				Expect(upsertTargetForUpstreamWithResponse_upstreamNameArg).To(Equal("test-route-name"))
+				Expect(upsertTargetForUpstreamWithResponse_targetIdArg).To(Equal("localhost:8080"))
 				expectedTargetTarget := "localhost:8080"
 				expectedTargetWeight := 100
-				Expect(createTargetForUpstreamWithResponse_targetBodyArg).To(Equal(kong.CreateTargetForUpstreamJSONRequestBody{
+				Expect(upsertTargetForUpstreamWithResponse_targetBodyArg).To(Equal(kong.UpsertTargetForUpstreamJSONRequestBody{
 					Tags:   &[]string{"env--test", "targets--test-route-name", "route--test-route-name"},
 					Target: &expectedTargetTarget,
 					Weight: &expectedTargetWeight,

gateway/pkg/kong/client/client.go

@@ -52,6 +52,7 @@
 
 	UpsertUpstreamWithResponse(ctx context.Context, upstreamIdOrName string, body kong.UpsertUpstreamJSONRequestBody, reqEditors ...kong.RequestEditorFn) (*kong.UpsertUpstreamResponse, error)
 	CreateTargetForUpstreamWithResponse(ctx context.Context, upstreamIdOrName string, body kong.CreateTargetForUpstreamJSONRequestBody, reqEditors ...kong.RequestEditorFn) (*kong.CreateTargetForUpstreamResponse, error)
+	UpsertTargetForUpstreamWithResponse(ctx context.Context, upstreamIdOrName string, targetIdOrTarget string, body kong.UpsertTargetForUpstreamJSONRequestBody, reqEditors ...kong.RequestEditorFn) (*kong.UpsertTargetForUpstreamResponse, error)
 	DeleteUpstreamWithResponse(ctx context.Context, upstreamIdOrName string, reqEditors ...kong.RequestEditorFn) (*kong.DeleteUpstreamResponse, error)
 	DeleteUpstreamTargetWithResponse(ctx context.Context, upstreamIdOrName string, targetIdOrTarget string, reqEditors ...kong.RequestEditorFn) (*kong.DeleteUpstreamTargetResponse, error)
 
@@ -71,7 +72,7 @@
 var _ KongClient = &kongClient{}
 
 type kongClient struct {
 	//client     kong.ClientWithResponsesInterface
 	client     KongAdminApi
 	commonTags []string
 }