listener options merge what translator generates (#10578)

Author: stevenctl

changelog/v1.19.0-beta10/merge-listener-options.yaml

@@ -0,0 +1,8 @@
+changelog:
+  - type: NON_USER_FACING
+    issueLink: https://github.com/solo-io/solo-projects/issues/7300
+    resolvesIssue: true
+    description: >-
+      If we generate any ListenerOptions from a Gateway to Proxy
+      translator, they will no longer be overridden by user
+      ListenerOptions.

projects/gateway2/translator/plugins/listeneroptions/listener_options_plugin.go

@@ -7,6 +7,7 @@ import (
 	"github.com/solo-io/gloo/projects/gateway2/translator/plugins"
 	lisquery "github.com/solo-io/gloo/projects/gateway2/translator/plugins/listeneroptions/query"
 	v1 "github.com/solo-io/gloo/projects/gloo/pkg/api/v1"
+	"github.com/solo-io/gloo/projects/gloo/pkg/utils"
 
 	"sigs.k8s.io/controller-runtime/pkg/client"
 )
@@ -47,7 +48,11 @@ func (p *plugin) ApplyListenerPlugin(
 	// use the first option (highest in priority)
 	// see for more context: https://github.com/solo-io/solo-projects/issues/6313
 	optToUse := attachedOptions[0]
-	outListener.Options = optToUse.Spec.GetOptions()
+	if outListener.GetOptions() != nil {
+		outListener.Options, _ = utils.ShallowMergeListenerOptions(outListener.GetOptions(), optToUse.Spec.GetOptions())
+	} else {
+		outListener.Options = optToUse.Spec.GetOptions()
+	}
 
 	return nil
 }

projects/gateway2/translator/plugins/listeneroptions/listener_options_plugin_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/solo-io/gloo/projects/gateway2/translator/testutils"
 	"github.com/solo-io/gloo/projects/gateway2/wellknown"
 	v1 "github.com/solo-io/gloo/projects/gloo/pkg/api/v1"
+	"github.com/solo-io/gloo/projects/gloo/pkg/api/v1/options/proxy_protocol"
 	corev1 "github.com/solo-io/skv2/pkg/api/core.skv2.solo.io/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"sigs.k8s.io/controller-runtime/pkg/client"
@@ -48,12 +49,19 @@ var _ = Describe("ListenerOptions Plugin", func() {
 				},
 			}
 
-			outputListener = &v1.Listener{}
+			outputListener = &v1.Listener{
+				Options: &v1.ListenerOptions{
+					ProxyProtocol: &proxy_protocol.ProxyProtocol{},
+				},
+			}
 
 			expectedOptions = &v1.ListenerOptions{
+				// from config
 				PerConnectionBufferLimitBytes: &wrapperspb.UInt32Value{
 					Value: uint32(419),
 				},
+				// base
+				ProxyProtocol: &proxy_protocol.ProxyProtocol{},
 			}
 		})
 		JustBeforeEach(func() {
@@ -102,7 +110,7 @@ var _ = Describe("ListenerOptions Plugin", func() {
 			It("does not add buffer limit", func() {
 				err := plugin.ApplyListenerPlugin(ctx, listenerCtx, outputListener)
 				Expect(err).ToNot(HaveOccurred())
-				Expect(outputListener.GetOptions()).To(BeNil())
+				Expect(outputListener.GetOptions().GetPerConnectionBufferLimitBytes()).To(BeNil())
 			})
 		})
 
@@ -114,11 +122,10 @@ var _ = Describe("ListenerOptions Plugin", func() {
 			It("does not add buffer limit", func() {
 				err := plugin.ApplyListenerPlugin(ctx, listenerCtx, outputListener)
 				Expect(err).ToNot(HaveOccurred())
-				Expect(outputListener.GetOptions()).To(BeNil())
+				Expect(outputListener.GetOptions().GetPerConnectionBufferLimitBytes()).To(BeNil())
 			})
 		})
 	})
-
 })
 
 func attachedListenerOption() *solokubev1.ListenerOption {
@@ -144,6 +151,7 @@ func attachedListenerOption() *solokubev1.ListenerOption {
 		},
 	}
 }
+
 func attachedListenerOptionWithSectionName() *solokubev1.ListenerOption {
 	listOpt := attachedListenerOption()
 	listOpt.Spec.TargetRefs[0].SectionName = &wrapperspb.StringValue{

projects/gloo/pkg/utils/merge.go

@@ -80,6 +80,32 @@ func isEmptyValue(v reflect.Value) bool {
 	return false
 }
 
+// ShallowMergeListenerOptions merges the top-level fields of src into dst.
+// The fields in dst that have non-zero values will not be overwritten.
+// It performs a shallow merge of top-level fields only.
+// It returns a boolean indicating whether any fields in src overwrote dst.
+func ShallowMergeListenerOptions(dst, src *v1.ListenerOptions) (*v1.ListenerOptions, bool) {
+	if src == nil {
+		return dst, false
+	}
+
+	if dst == nil {
+		return src.Clone().(*v1.ListenerOptions), true
+	}
+
+	dstValue, srcValue := reflect.ValueOf(dst).Elem(), reflect.ValueOf(src).Elem()
+
+	overwrote := false
+	for i := range dstValue.NumField() {
+		dstField, srcField := dstValue.Field(i), srcValue.Field(i)
+		if srcOverride := ShallowMerge(dstField, srcField); srcOverride {
+			overwrote = true
+		}
+	}
+
+	return dst, overwrote
+}
+
 // ShallowMergeRouteOptions merges the top-level fields of src into dst.
 // The fields in dst that have non-zero values will not be overwritten.
 // It performs a shallow merge of top-level fields only.