From 122910c65dbb95235bdaeb54d327d84c94eb03d2 Mon Sep 17 00:00:00 2001 From: FedotCompot Date: Fri, 20 Jun 2025 14:33:40 +0200 Subject: [PATCH] feat(k8s): ExternalName service support (#419) --- README.md | 10 +++-- server/k8s.go | 19 +++++++-- server/k8s_test.go | 100 ++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 121 insertions(+), 8 deletions(-) diff --git a/README.md b/README.md index f4205e0..c991943 100644 --- a/README.md +++ b/README.md @@ -220,8 +220,8 @@ For more information on the allow/deny list configuration, see the [json schema] ### Using Kubernetes Service auto-discovery When running `mc-router` as a Kubernetes Pod and you pass the `--in-kube-cluster` command-line argument, then it will automatically watch for any services annotated with -- `mc-router.itzg.me/externalServerName` : The value of the annotation will be registered as the external hostname Minecraft clients would used to connect to the routed service. The service's clusterIP and target port are used as the routed backend. You can use more hostnames by splitting them with comma. -- `mc-router.itzg.me/defaultServer` : The service's clusterIP and target port are used as the default if no other `externalServiceName` annotations applies. +- `mc-router.itzg.me/externalServerName` : The value of the annotation will be registered as the external hostname Minecraft clients would used to connect to the routed service. The service is used as the routed backend. You can use more hostnames by splitting them with comma. +- `mc-router.itzg.me/defaultServer` : The service is used as the default if no other `externalServiceName` annotations applies. For example, start `mc-router`'s container spec with @@ -253,7 +253,11 @@ metadata: "mc-router.itzg.me/externalServerName": "external.host.name,other.host.name" ``` -mc-router will pick the service port named either `minecraft` or `mc-router`. If neither port names exist, it will use port value 25565. +### Service parsing + +To detrmine the endpoint mc-router will pick the host from `spec.clusterIP` by default, if the service is of type `ExtenalName` it will use `spec.externalName` instead. + +For the port it will look in `spec.ports` for a port named `mc-router`, if not present `minecraft` or, if neither port names exist, it will use default minecraft port value 25565. ### Example Kubernetes deployment diff --git a/server/k8s.go b/server/k8s.go index df4cc21..75a554e 100644 --- a/server/k8s.go +++ b/server/k8s.go @@ -235,11 +235,24 @@ func (w *k8sWatcherImpl) extractRoutableServices(obj interface{}) []*routableSer func (w *k8sWatcherImpl) buildDetails(service *core.Service, externalServiceName string) *routableService { clusterIp := service.Spec.ClusterIP - port := "25565" + if service.Spec.Type == core.ServiceTypeExternalName { + clusterIp = service.Spec.ExternalName + } + mcRouterPort := "" + mcPort := "" for _, p := range service.Spec.Ports { - if p.Name == "mc-router" || p.Name == "minecraft" { - port = strconv.Itoa(int(p.Port)) + if p.Name == "mc-router" { + mcRouterPort = strconv.Itoa(int(p.Port)) } + if p.Name == "minecraft" { + mcPort = strconv.Itoa(int(p.Port)) + } + } + port := "25565" + if len(mcRouterPort) > 0 { + port = mcRouterPort + } else if len(mcPort) > 0 { + port = mcPort } rs := &routableService{ externalServiceName: externalServiceName, diff --git a/server/k8s_test.go b/server/k8s_test.go index ac2d41e..0820903 100644 --- a/server/k8s_test.go +++ b/server/k8s_test.go @@ -80,7 +80,7 @@ func TestK8sWatcherImpl_handleAddThenUpdate(t *testing.T) { for _, test := range tests { t.Run(test.name, func(t *testing.T) { // DownScaler needs to be instantiated - DownScaler = NewDownScaler(context.Background(), false, 1 * time.Second) + DownScaler = NewDownScaler(context.Background(), false, 1*time.Second) Routes.Reset() watcher := &k8sWatcherImpl{} @@ -153,7 +153,7 @@ func TestK8sWatcherImpl_handleAddThenDelete(t *testing.T) { for _, test := range tests { t.Run(test.name, func(t *testing.T) { // DownScaler needs to be instantiated - DownScaler = NewDownScaler(context.Background(), false, 1 * time.Second) + DownScaler = NewDownScaler(context.Background(), false, 1*time.Second) Routes.Reset() watcher := &k8sWatcherImpl{} @@ -175,3 +175,99 @@ func TestK8sWatcherImpl_handleAddThenDelete(t *testing.T) { }) } } + +func TestK8s_externalName(t *testing.T) { + type scenario struct { + given string + expect string + } + type svcAndScenarios struct { + svc string + scenarios []scenario + } + tests := []struct { + name string + initial svcAndScenarios + update svcAndScenarios + }{ + { + name: "typeChange", + initial: svcAndScenarios{ + svc: ` {"metadata": {"annotations": {"mc-router.itzg.me/externalServerName": "a.com"}}, "spec":{"type":"ExternalName", "externalName": "mc-server.com"}}`, + scenarios: []scenario{ + {given: "a.com", expect: "mc-server.com:25565"}, + {given: "b.com", expect: ""}, + }, + }, + update: svcAndScenarios{ + svc: ` {"metadata": {"annotations": {"mc-router.itzg.me/externalServerName": "a.com"}}, "spec":{"clusterIP": "1.1.1.1"}}`, + scenarios: []scenario{ + {given: "a.com", expect: "1.1.1.1:25565"}, + {given: "b.com", expect: ""}, + }, + }, + }, + { + name: "typeAndServerChange", + initial: svcAndScenarios{ + svc: ` {"metadata": {"annotations": {"mc-router.itzg.me/externalServerName": "a.com"}}, "spec":{"type":"ExternalName", "externalName": "mc-server.com"}}`, + scenarios: []scenario{ + {given: "a.com", expect: "mc-server.com:25565"}, + {given: "b.com", expect: ""}, + }, + }, + update: svcAndScenarios{ + svc: ` {"metadata": {"annotations": {"mc-router.itzg.me/externalServerName": "b.com"}}, "spec":{"clusterIP": "1.1.1.1"}}`, + scenarios: []scenario{ + {given: "a.com", expect: ""}, + {given: "b.com", expect: "1.1.1.1:25565"}, + }, + }, + }, + { + name: "externalNameChange", + initial: svcAndScenarios{ + svc: ` {"metadata": {"annotations": {"mc-router.itzg.me/externalServerName": "a.com,b.com"}}, "spec":{"type":"ExternalName", "externalName": "mc-server.com"}}`, + scenarios: []scenario{ + {given: "a.com", expect: "mc-server.com:25565"}, + {given: "b.com", expect: "mc-server.com:25565"}, + }, + }, + update: svcAndScenarios{ + svc: ` {"metadata": {"annotations": {"mc-router.itzg.me/externalServerName": "a.com,b.com"}}, "spec":{"type":"ExternalName", "externalName": "1.1.1.1"}}`, + scenarios: []scenario{ + {given: "a.com", expect: "1.1.1.1:25565"}, + {given: "b.com", expect: "1.1.1.1:25565"}, + }, + }, + }, + } + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + // DownScaler needs to be instantiated + DownScaler = NewDownScaler(context.Background(), false, 1*time.Second) + Routes.Reset() + + watcher := &k8sWatcherImpl{} + initialSvc := v1.Service{} + err := json.Unmarshal([]byte(test.initial.svc), &initialSvc) + require.NoError(t, err) + + watcher.handleAdd(&initialSvc) + for _, s := range test.initial.scenarios { + backend, _, _, _ := Routes.FindBackendForServerAddress(context.Background(), s.given) + assert.Equal(t, s.expect, backend, "initial: given=%s", s.given) + } + + updatedSvc := v1.Service{} + err = json.Unmarshal([]byte(test.update.svc), &updatedSvc) + require.NoError(t, err) + + watcher.handleUpdate(&initialSvc, &updatedSvc) + for _, s := range test.update.scenarios { + backend, _, _, _ := Routes.FindBackendForServerAddress(context.Background(), s.given) + assert.Equal(t, s.expect, backend, "update: given=%s", s.given) + } + }) + } +}