From 1d12bb4f4c22ecd39638bcff85646cdc2caddfe4 Mon Sep 17 00:00:00 2001
From: Alexander Nicke <alexander.nicke@sap.com>
Date: Fri, 18 Oct 2024 10:52:47 +0200
Subject: [PATCH] feat: implement support for per-route options

This commit adds the Options field to the RegistryMessage and Route
struct.
Required for route-emitter to forward the per-route-options.

Co-authored-by: Tamara Boehm <tamara.boehm@sap.com>
See: https://github.com/cloudfoundry/community/issues/909
---
 routehandlers/handler_test.go         |  1 +
 routingtable/endpoint.go              |  2 ++
 routingtable/registry_message.go      |  3 ++
 routingtable/registry_message_test.go | 40 +++++++++++++++++++++++++++
 routingtable/routingtable.go          |  1 +
 5 files changed, 47 insertions(+)

diff --git a/routehandlers/handler_test.go b/routehandlers/handler_test.go
index 5ca7846..3ec55f2 100644
--- a/routehandlers/handler_test.go
+++ b/routehandlers/handler_test.go
@@ -1076,6 +1076,7 @@ var _ = Describe("Handler", func() {
 						Hostnames:       []string{hostname1},
 						Port:            8080,
 						RouteServiceUrl: "https://rs.example.com",
+						Options:         json.RawMessage(`{"lb_algo":"least-connection"}`),
 					},
 				}.RoutingInfo()
 
diff --git a/routingtable/endpoint.go b/routingtable/endpoint.go
index 95fab5a..d312c2e 100644
--- a/routingtable/endpoint.go
+++ b/routingtable/endpoint.go
@@ -1,6 +1,7 @@
 package routingtable
 
 import (
+	"encoding/json"
 	"fmt"
 
 	"code.cloudfoundry.org/bbs/models"
@@ -141,6 +142,7 @@ type Route struct {
 	LogGUID          string
 	Protocol         string
 	MetricTags       map[string]*models.MetricTagValue
+	Options          json.RawMessage
 }
 
 type routeHash struct {
diff --git a/routingtable/registry_message.go b/routingtable/registry_message.go
index b6a77d2..9c15c05 100644
--- a/routingtable/registry_message.go
+++ b/routingtable/registry_message.go
@@ -1,6 +1,7 @@
 package routingtable
 
 import (
+	"encoding/json"
 	"fmt"
 	"strconv"
 
@@ -22,6 +23,7 @@ type RegistryMessage struct {
 	EndpointUpdatedAtNs  int64             `json:"endpoint_updated_at_ns,omitempty" hash:"ignore"`
 	Tags                 map[string]string `json:"tags,omitempty" hash:"ignore"`
 	AvailabilityZone     string            `json:"availability_zone,omitempty" hash:"ignore"`
+	Options              json.RawMessage   `json:"options,omitempty" hash:"ignore"`
 }
 
 func RegistryMessageFor(endpoint Endpoint, route Route, emitEndpointUpdatedAt bool) RegistryMessage {
@@ -50,6 +52,7 @@ func RegistryMessageFor(endpoint Endpoint, route Route, emitEndpointUpdatedAt bo
 		PrivateInstanceIndex: index,
 		ServerCertDomainSAN:  endpoint.InstanceGUID,
 		RouteServiceUrl:      route.RouteServiceUrl,
+		Options:              route.Options,
 	}
 }
 
diff --git a/routingtable/registry_message_test.go b/routingtable/registry_message_test.go
index 1bf428a..aeec82c 100644
--- a/routingtable/registry_message_test.go
+++ b/routingtable/registry_message_test.go
@@ -120,6 +120,34 @@ var _ = Describe("RegistryMessage", func() {
 				Expect(message).To(Equal(expectedMessage))
 			})
 		})
+
+		Context("when a route option is provided", func() {
+			BeforeEach(func() {
+				expectedMessage.Options = json.RawMessage(`{"lb_algo":"least-connection"}`)
+				expectedJSON = `{
+				"host": "1.1.1.1",
+				"port": 61001,
+				"uris": ["host-1.example.com"],
+				"app" : "app-guid",
+				"private_instance_id": "instance-guid",
+				"server_cert_domain_san": "instance-guid",
+				"private_instance_index": "0",
+				"route_service_url": "https://hello.com",
+				"endpoint_updated_at_ns": 1000,
+				"tags": {"component":"route-emitter", "doo": "0", "foo": "bar", "goo": "instance-guid"},
+				"availability_zone": "some-zone",
+				"options": {"lb_algo":"least-connection"}
+			}`
+			})
+
+			It("correctly marshals the route option", func() {
+				message := routingtable.RegistryMessage{}
+
+				err := json.Unmarshal([]byte(expectedJSON), &message)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(message).To(Equal(expectedMessage))
+			})
+		})
 	})
 
 	Describe("RegistryMessageFor", func() {
@@ -182,6 +210,18 @@ var _ = Describe("RegistryMessage", func() {
 				Expect(message).To(Equal(expectedMessage))
 			})
 		})
+
+		Context("when route options are provided", func() {
+			BeforeEach(func() {
+				route.Options = json.RawMessage(`{"lb_algo":"least-connection"}`)
+				expectedMessage.Options = json.RawMessage(`{"lb_algo":"least-connection"}`)
+			})
+
+			It("creates a valid message when route options are provided", func() {
+				message := routingtable.RegistryMessageFor(endpoint, route, true)
+				Expect(message).To(Equal(expectedMessage))
+			})
+		})
 	})
 
 	Describe("InternalAddressRegistryMessageFor", func() {
diff --git a/routingtable/routingtable.go b/routingtable/routingtable.go
index 1360ee4..ecd50b8 100644
--- a/routingtable/routingtable.go
+++ b/routingtable/routingtable.go
@@ -444,6 +444,7 @@ func httpRoutesFrom(lrp *models.DesiredLRP) map[RoutingKey][]routeMapping {
 				IsolationSegment: route.IsolationSegment,
 				MetricTags:       lrp.MetricTags,
 				Protocol:         route.Protocol,
+				Options:          route.Options,
 			}
 			routes = append(routes, route)
 		}