Initial commit

server/routes.go

@@ -0,0 +1,131 @@
+package server
+
+import (
+	"sync"
+	"net/http"
+	"encoding/json"
+	"github.com/sirupsen/logrus"
+	"github.com/gorilla/mux"
+)
+
+func init() {
+	apiRoutes.Path("/routes").Methods("GET").
+		Headers("Accept", "application/json").
+		HandlerFunc(routesListHandler)
+	apiRoutes.Path("/routes").Methods("POST").
+		Headers("Content-Type", "application/json").
+		HandlerFunc(routesCreateHandler)
+	apiRoutes.Path("/routes/{serverAddress}").Methods("DELETE").HandlerFunc(routesDeleteHandler)
+}
+
+func routesListHandler(writer http.ResponseWriter, request *http.Request) {
+	mappings := Routes.GetMappings()
+	bytes, err := json.Marshal(mappings)
+	if err != nil {
+		logrus.WithError(err).Error("Failed to marshal mappings")
+		writer.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	writer.Write(bytes)
+}
+
+func routesDeleteHandler(writer http.ResponseWriter, request *http.Request) {
+	serverAddress := mux.Vars(request)["serverAddress"]
+	if serverAddress != "" {
+		if Routes.DeleteMapping(serverAddress) {
+			writer.WriteHeader(http.StatusOK)
+		} else {
+			writer.WriteHeader(http.StatusNotFound)
+		}
+	}
+}
+
+func routesCreateHandler(writer http.ResponseWriter, request *http.Request) {
+	var definition = struct {
+		ServerAddress string
+		Backend string
+	}{}
+
+	defer request.Body.Close()
+
+	decoder := json.NewDecoder(request.Body)
+	err := decoder.Decode(&definition)
+	if err != nil {
+		logrus.WithError(err).Error("Unable to get request body")
+		writer.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	Routes.CreateMapping(definition.ServerAddress, definition.Backend)
+	writer.WriteHeader(http.StatusCreated)
+}
+
+type IRoutes interface {
+	RegisterAll(mappings map[string]string)
+	// FindBackendForServerAddress returns the host:port for the external server address, if registered.
+	// Otherwise, an empty string is returned
+	FindBackendForServerAddress(serverAddress string) string
+	GetMappings() map[string]string
+	DeleteMapping(serverAddress string) bool
+	CreateMapping(serverAddress string, backend string)
+}
+
+var Routes IRoutes = &routesImpl{}
+
+func (r *routesImpl) RegisterAll(mappings map[string]string) {
+	r.Lock()
+	defer r.Unlock()
+
+	r.mappings = mappings
+}
+
+type routesImpl struct {
+	sync.RWMutex
+	mappings   map[string]string
+}
+
+func (r *routesImpl) FindBackendForServerAddress(serverAddress string) string {
+	r.RLock()
+	defer r.RUnlock()
+
+	if r.mappings == nil {
+		return ""
+	} else {
+		return r.mappings[serverAddress]
+	}
+}
+
+func (r *routesImpl) GetMappings() map[string]string {
+	r.RLock()
+	defer r.RUnlock()
+
+	result := make(map[string]string, len(r.mappings))
+	for k, v := range r.mappings {
+		result[k] = v
+	}
+	return result
+}
+
+func (r *routesImpl) DeleteMapping(serverAddress string) bool {
+	r.Lock()
+	defer r.Unlock()
+	logrus.WithField("serverAddress", serverAddress).Info("Deleting route")
+
+	if _, ok := r.mappings[serverAddress]; ok {
+		delete(r.mappings, serverAddress)
+		return true
+	} else {
+		return false
+	}
+}
+
+func (r *routesImpl) CreateMapping(serverAddress string, backend string) {
+	r.Lock()
+	defer r.Unlock()
+
+	logrus.WithFields(logrus.Fields{
+		"serverAddress": serverAddress,
+		"backend": backend,
+	}).Info("Creating route")
+	r.mappings[serverAddress] = backend
+}