Auto-register routes based on kubernetes service annotations

.circleci/config.yml

@@ -24,14 +24,16 @@ jobs:
 
       - restore_cache:
           keys:
-            - cache-{{ arch }}-{{ .Branch }}-{{ checksum "Gopkg.lock" }}
+            - cache-{{ arch }}-{{ .Branch }}-{{ checksum "glide.lock" }}
             - cache-{{ arch }}-{{ .Branch }}
             - cache
 
-      - run: make install-dep
+      - run:
+          name: install dependencies
+          command: glide install
 
       - save_cache:
-          key: cache-{{ arch }}-{{ .Branch }}-{{ checksum "Gopkg.lock" }}
+          key: cache-{{ arch }}-{{ .Branch }}-{{ checksum "glide.lock" }}
           paths:
             - vendor
 
@@ -42,7 +44,9 @@ jobs:
     steps:
       - checkout
 
-      - run: make install-dep
+      - run:
+          name: install dependencies
+          command: glide install
 
       - setup_remote_docker
       - run: echo $DOCKER_PASSWORD | docker login -u $DOCKER_USER --password-stdin

Gopkg.lock

@@ -1,63 +0,0 @@
-# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
-
-
-[[projects]]
-  name = "github.com/alecthomas/kingpin"
-  packages = ["."]
-  revision = "947dcec5ba9c011838740e680966fd7087a71d0d"
-  version = "v2.2.6"
-
-[[projects]]
-  branch = "master"
-  name = "github.com/alecthomas/template"
-  packages = [
-    ".",
-    "parse"
-  ]
-  revision = "a0175ee3bccc567396460bf5acd36800cb10c49c"
-
-[[projects]]
-  branch = "master"
-  name = "github.com/alecthomas/units"
-  packages = ["."]
-  revision = "2efee857e7cfd4f3d0138cc3cbb1b4966962b93a"
-
-[[projects]]
-  name = "github.com/gorilla/context"
-  packages = ["."]
-  revision = "1ea25387ff6f684839d82767c1733ff4d4d15d0a"
-  version = "v1.1"
-
-[[projects]]
-  name = "github.com/gorilla/mux"
-  packages = ["."]
-  revision = "53c1911da2b537f792e7cafcb446b05ffe33b996"
-  version = "v1.6.1"
-
-[[projects]]
-  name = "github.com/sirupsen/logrus"
-  packages = ["."]
-  revision = "c155da19408a8799da419ed3eeb0cb5db0ad5dbc"
-  version = "v1.0.5"
-
-[[projects]]
-  branch = "master"
-  name = "golang.org/x/crypto"
-  packages = ["ssh/terminal"]
-  revision = "4ec37c66abab2c7e02ae775328b2ff001c3f025a"
-
-[[projects]]
-  branch = "master"
-  name = "golang.org/x/sys"
-  packages = [
-    "unix",
-    "windows"
-  ]
-  revision = "6f686a352de66814cdd080d970febae7767857a3"
-
-[solve-meta]
-  analyzer-name = "dep"
-  analyzer-version = 1
-  inputs-digest = "8d17b95931fea7bbf18743367ccc152c392add293fe7945ca9ce941ca1482b4f"
-  solver-name = "gps-cdcl"
-  solver-version = 1

Gopkg.toml

@@ -1,38 +0,0 @@
-# Gopkg.toml example
-#
-# Refer to https://github.com/golang/dep/blob/master/docs/Gopkg.toml.md
-# for detailed Gopkg.toml documentation.
-#
-# required = ["github.com/user/thing/cmd/thing"]
-# ignored = ["github.com/user/project/pkgX", "bitbucket.org/user/project/pkgA/pkgY"]
-#
-# [[constraint]]
-#   name = "github.com/user/project"
-#   version = "1.0.0"
-#
-# [[constraint]]
-#   name = "github.com/user/project2"
-#   branch = "dev"
-#   source = "github.com/myfork/project2"
-#
-# [[override]]
-#   name = "github.com/x/y"
-#   version = "2.4.0"
-#
-# [prune]
-#   non-go = false
-#   go-tests = true
-#   unused-packages = true
-
-
-[prune]
-  go-tests = true
-  unused-packages = true
-
-[[constraint]]
-  name = "github.com/alecthomas/kingpin"
-  version = "2.2.6"
-
-[[constraint]]
-  name = "github.com/sirupsen/logrus"
-  version = "1.0.5"

cmd/mc-router/main.go

@@ -1,35 +1,36 @@
 package main
 
 import (
-	"net"
-	"github.com/itzg/mc-router/server"
-	"github.com/alecthomas/kingpin"
-	"strconv"
-	"github.com/sirupsen/logrus"
 	"context"
+	"fmt"
+	"github.com/alecthomas/kingpin"
+	"github.com/itzg/mc-router/server"
+	"github.com/sirupsen/logrus"
+	"net"
 	"os"
 	"os/signal"
-	"fmt"
+	"strconv"
 )
 
 var (
 	port = kingpin.Flag("port", "The port bound to listen for Minecraft client connections").
 		Default("25565").Int()
 	apiBinding = kingpin.Flag("api-binding", "The host:port bound for servicing API requests").
-		String()
+			String()
 	mappings = kingpin.Flag("mapping", "Mapping of external hostname to internal server host:port").
-		StringMap()
+			StringMap()
 	versionFlag = kingpin.Flag("version", "Output version and exit").
-		Bool()
+			Bool()
+	kubeConfigFile = kingpin.Flag("kube-config", "The path to a kubernetes configuration file").String()
 )
 
 var (
 	version = "dev"
-	commit = "none"
+	commit  = "none"
-	date = "unknown"
+	date    = "unknown"
 )
 
-func showVersion()  {
+func showVersion() {
 	fmt.Printf("%v, commit %v, built at %v", version, commit, date)
 }
 
@@ -54,6 +55,13 @@ func main() {
 		server.StartApiServer(*apiBinding)
 	}
 
+	err := server.K8sWatcher.Start(*kubeConfigFile)
+	if err != nil {
+		logrus.WithError(err).Warn("Skipping kubernetes integration")
+	} else {
+		defer server.K8sWatcher.Stop()
+	}
+
 	<-c
 	logrus.Info("Stopping")
 	cancel()

glide.lock

@@ -0,0 +1,238 @@
+hash: d0042501db8c547ec44ff6828ff8b0c7d08561d95311f4c62cf8014e6a02e97e
+updated: 2018-05-26T11:09:13.8257578-05:00
+imports:
+- name: github.com/alecthomas/kingpin
+  version: 947dcec5ba9c011838740e680966fd7087a71d0d
+- name: github.com/alecthomas/template
+  version: a0175ee3bccc567396460bf5acd36800cb10c49c
+  subpackages:
+  - parse
+- name: github.com/alecthomas/units
+  version: 2efee857e7cfd4f3d0138cc3cbb1b4966962b93a
+- name: github.com/davecgh/go-spew
+  version: 782f4967f2dc4564575ca782fe2d04090b5faca8
+  subpackages:
+  - spew
+- name: github.com/ghodss/yaml
+  version: 73d445a93680fa1a78ae23a5839bad48f32ba1ee
+- name: github.com/gogo/protobuf
+  version: c0656edd0d9eab7c66d1eb0c568f9039345796f7
+  subpackages:
+  - proto
+  - sortkeys
+- name: github.com/golang/glog
+  version: 44145f04b68cf362d9c4df2182967c2275eaefed
+- name: github.com/golang/protobuf
+  version: 1643683e1b54a9e88ad26d98f81400c8c9d9f4f9
+  subpackages:
+  - proto
+  - ptypes
+  - ptypes/any
+  - ptypes/duration
+  - ptypes/timestamp
+- name: github.com/google/gofuzz
+  version: 44d81051d367757e1c7c6a5a86423ece9afcf63c
+- name: github.com/googleapis/gnostic
+  version: 0c5108395e2debce0d731cf0287ddf7242066aba
+  subpackages:
+  - OpenAPIv2
+  - compiler
+  - extensions
+- name: github.com/gorilla/context
+  version: 08b5f424b9271eedf6f9f0ce86cb9396ed337a42
+- name: github.com/gorilla/mux
+  version: e3702bed27f0d39777b0b37b664b6280e8ef8fbf
+- name: github.com/hashicorp/golang-lru
+  version: a0d98a5f288019575c6d1f4bb1573fef2d1fcdc4
+  subpackages:
+  - simplelru
+- name: github.com/howeyc/gopass
+  version: bf9dde6d0d2c004a008c27aaee91170c786f6db8
+- name: github.com/imdario/mergo
+  version: 6633656539c1639d9d78127b7d47c622b5d7b6dc
+- name: github.com/json-iterator/go
+  version: 13f86432b882000a51c6e610c620974462691a97
+- name: github.com/pkg/errors
+  version: 645ef00459ed84a119197bfb8d8205042c6df63d
+- name: github.com/sirupsen/logrus
+  version: c155da19408a8799da419ed3eeb0cb5db0ad5dbc
+- name: github.com/spf13/pflag
+  version: 4c012f6dcd9546820e378d0bdda4d8fc772cdfea
+- name: golang.org/x/crypto
+  version: a3beeb748656e13e54256fd2cde19e058f41f60f
+  subpackages:
+  - ssh/terminal
+- name: golang.org/x/net
+  version: 1c05540f6879653db88113bc4a2b70aec4bd491f
+  subpackages:
+  - context
+  - context/ctxhttp
+  - http2
+  - http2/hpack
+  - idna
+  - lex/httplex
+- name: golang.org/x/sys
+  version: 95c6576299259db960f6c5b9b69ea52422860fce
+  subpackages:
+  - unix
+  - windows
+- name: golang.org/x/text
+  version: b19bf474d317b857955b12035d2c5acb57ce8b01
+  subpackages:
+  - secure/bidirule
+  - transform
+  - unicode/bidi
+  - unicode/norm
+- name: golang.org/x/time
+  version: f51c12702a4d776e4c1fa9b0fabab841babae631
+  subpackages:
+  - rate
+- name: gopkg.in/inf.v0
+  version: 3887ee99ecf07df5b447e9b00d9c0b2adaa9f3e4
+- name: gopkg.in/yaml.v2
+  version: 670d4cfef0544295bc27a114dbac37980d83185a
+- name: k8s.io/api
+  version: 73d903622b7391f3312dcbac6483fed484e185f8
+  subpackages:
+  - admissionregistration/v1alpha1
+  - admissionregistration/v1beta1
+  - apps/v1
+  - apps/v1beta1
+  - apps/v1beta2
+  - authentication/v1
+  - authentication/v1beta1
+  - authorization/v1
+  - authorization/v1beta1
+  - autoscaling/v1
+  - autoscaling/v2beta1
+  - batch/v1
+  - batch/v1beta1
+  - batch/v2alpha1
+  - certificates/v1beta1
+  - core/v1
+  - events/v1beta1
+  - extensions/v1beta1
+  - imagepolicy/v1alpha1
+  - networking/v1
+  - policy/v1beta1
+  - rbac/v1
+  - rbac/v1alpha1
+  - rbac/v1beta1
+  - scheduling/v1alpha1
+  - settings/v1alpha1
+  - storage/v1
+  - storage/v1alpha1
+  - storage/v1beta1
+- name: k8s.io/apimachinery
+  version: 302974c03f7e50f16561ba237db776ab93594ef6
+  subpackages:
+  - pkg/api/equality
+  - pkg/api/errors
+  - pkg/api/meta
+  - pkg/api/resource
+  - pkg/api/testing
+  - pkg/api/testing/fuzzer
+  - pkg/api/testing/roundtrip
+  - pkg/apimachinery
+  - pkg/apimachinery/announced
+  - pkg/apimachinery/registered
+  - pkg/apis/meta/fuzzer
+  - pkg/apis/meta/internalversion
+  - pkg/apis/meta/v1
+  - pkg/apis/meta/v1/unstructured
+  - pkg/apis/meta/v1beta1
+  - pkg/conversion
+  - pkg/conversion/queryparams
+  - pkg/fields
+  - pkg/labels
+  - pkg/runtime
+  - pkg/runtime/schema
+  - pkg/runtime/serializer
+  - pkg/runtime/serializer/json
+  - pkg/runtime/serializer/protobuf
+  - pkg/runtime/serializer/recognizer
+  - pkg/runtime/serializer/streaming
+  - pkg/runtime/serializer/versioning
+  - pkg/selection
+  - pkg/types
+  - pkg/util/cache
+  - pkg/util/clock
+  - pkg/util/diff
+  - pkg/util/errors
+  - pkg/util/framer
+  - pkg/util/httpstream
+  - pkg/util/httpstream/spdy
+  - pkg/util/intstr
+  - pkg/util/json
+  - pkg/util/mergepatch
+  - pkg/util/net
+  - pkg/util/remotecommand
+  - pkg/util/runtime
+  - pkg/util/sets
+  - pkg/util/strategicpatch
+  - pkg/util/validation
+  - pkg/util/validation/field
+  - pkg/util/wait
+  - pkg/util/yaml
+  - pkg/version
+  - pkg/watch
+  - third_party/forked/golang/json
+  - third_party/forked/golang/netutil
+  - third_party/forked/golang/reflect
+- name: k8s.io/client-go
+  version: 23781f4d6632d88e869066eaebb743857aa1ef9b
+  subpackages:
+  - discovery
+  - kubernetes
+  - kubernetes/scheme
+  - kubernetes/typed/admissionregistration/v1alpha1
+  - kubernetes/typed/admissionregistration/v1beta1
+  - kubernetes/typed/apps/v1
+  - kubernetes/typed/apps/v1beta1
+  - kubernetes/typed/apps/v1beta2
+  - kubernetes/typed/authentication/v1
+  - kubernetes/typed/authentication/v1beta1
+  - kubernetes/typed/authorization/v1
+  - kubernetes/typed/authorization/v1beta1
+  - kubernetes/typed/autoscaling/v1
+  - kubernetes/typed/autoscaling/v2beta1
+  - kubernetes/typed/batch/v1
+  - kubernetes/typed/batch/v1beta1
+  - kubernetes/typed/batch/v2alpha1
+  - kubernetes/typed/certificates/v1beta1
+  - kubernetes/typed/core/v1
+  - kubernetes/typed/events/v1beta1
+  - kubernetes/typed/extensions/v1beta1
+  - kubernetes/typed/networking/v1
+  - kubernetes/typed/policy/v1beta1
+  - kubernetes/typed/rbac/v1
+  - kubernetes/typed/rbac/v1alpha1
+  - kubernetes/typed/rbac/v1beta1
+  - kubernetes/typed/scheduling/v1alpha1
+  - kubernetes/typed/settings/v1alpha1
+  - kubernetes/typed/storage/v1
+  - kubernetes/typed/storage/v1alpha1
+  - kubernetes/typed/storage/v1beta1
+  - pkg/apis/clientauthentication
+  - pkg/apis/clientauthentication/v1alpha1
+  - pkg/version
+  - plugin/pkg/client/auth/exec
+  - rest
+  - rest/watch
+  - tools/auth
+  - tools/cache
+  - tools/clientcmd
+  - tools/clientcmd/api
+  - tools/clientcmd/api/latest
+  - tools/clientcmd/api/v1
+  - tools/metrics
+  - tools/pager
+  - tools/reference
+  - transport
+  - util/buffer
+  - util/cert
+  - util/flowcontrol
+  - util/homedir
+  - util/integer
+  - util/retry
+testImports: []

glide.yaml

@@ -0,0 +1,16 @@
+package: github.com/itzg/mc-router
+import:
+- package: github.com/alecthomas/kingpin
+  version: ^2.2.6
+- package: github.com/gorilla/mux
+  version: ^1.6.2
+- package: github.com/pkg/errors
+  version: ^0.8.0
+- package: github.com/sirupsen/logrus
+  version: ^1.0.5
+- package: k8s.io/client-go
+  version: ^7.0.0
+  subpackages:
+  - kubernetes
+  - tools/cache
+  - tools/clientcmd

server/k8s.go

@@ -0,0 +1,122 @@
+package server
+
+import (
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/fields"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/tools/cache"
+	"k8s.io/client-go/tools/clientcmd"
+	"net"
+)
+
+type IK8sWatcher interface {
+	Start(kubeConfigFile string) error
+	Stop()
+}
+
+var K8sWatcher IK8sWatcher = &k8sWatcherImpl{}
+
+type k8sWatcherImpl struct {
+	stop chan struct{}
+}
+
+func (w *k8sWatcherImpl) Start(kubeConfigFile string) error {
+	config, err := clientcmd.BuildConfigFromFlags("", kubeConfigFile)
+	if err != nil {
+		return errors.Wrap(err, "Could not load kube config file")
+	}
+
+	clientset, err := kubernetes.NewForConfig(config)
+	if err != nil {
+		return errors.Wrap(err, "Could not create kube clientset")
+	}
+
+	watchlist := cache.NewListWatchFromClient(
+		clientset.CoreV1().RESTClient(),
+		string(v1.ResourceServices),
+		v1.NamespaceAll,
+		fields.Everything(),
+	)
+
+	_, controller := cache.NewInformer(
+		watchlist,
+		&v1.Service{},
+		0,
+		cache.ResourceEventHandlerFuncs{
+			AddFunc: func(obj interface{}) {
+				routableService := extractRoutableService(obj)
+				if routableService != nil {
+					logrus.WithField("routableService", routableService).Debug("ADD")
+
+					Routes.CreateMapping(routableService.externalServiceName, routableService.containerEndpoint)
+				}
+			},
+			DeleteFunc: func(obj interface{}) {
+				routableService := extractRoutableService(obj)
+				if routableService != nil {
+					logrus.WithField("routableService", routableService).Debug("DELETE")
+
+					Routes.DeleteMapping(routableService.externalServiceName)
+				}
+			},
+			UpdateFunc: func(oldObj, newObj interface{}) {
+				oldRoutableService := extractRoutableService(oldObj)
+				newRoutableService := extractRoutableService(newObj)
+				if oldRoutableService != nil && newRoutableService != nil {
+					logrus.WithFields(logrus.Fields{
+						"old": oldRoutableService,
+						"new": newRoutableService,
+					}).Debug("UPDATE")
+
+					Routes.DeleteMapping(oldRoutableService.externalServiceName)
+					Routes.CreateMapping(newRoutableService.externalServiceName, newRoutableService.containerEndpoint)
+				}
+			},
+		},
+	)
+
+	w.stop = make(chan struct{}, 1)
+	logrus.Info("Monitoring kubernetes for minecraft services")
+	go controller.Run(w.stop)
+
+	return nil
+}
+
+func (w *k8sWatcherImpl) Stop() {
+	if w.stop != nil {
+		w.stop <- struct{}{}
+	}
+}
+
+type routableService struct {
+	externalServiceName string
+	containerEndpoint   string
+}
+
+func extractRoutableService(obj interface{}) *routableService {
+	service, ok := obj.(*v1.Service)
+	if !ok {
+		return nil
+	}
+
+	if externalServiceName, exists := service.Annotations["mc-router.itzg.me/externalServerName"]; exists {
+		clusterIp := service.Spec.ClusterIP
+		port := "25565"
+		for _, p := range service.Spec.Ports {
+			if p.Port == 25565 {
+				if p.TargetPort.String() != "" {
+					port = p.TargetPort.String()
+				}
+			}
+		}
+		rs := &routableService{
+			externalServiceName: externalServiceName,
+			containerEndpoint:   net.JoinHostPort(clusterIp, port),
+		}
+		return rs
+	}
+
+	return nil
+}