package registry import ( "net/http" "github.com/docker/docker-registry/storagedriver" "github.com/docker/docker-registry/storagedriver/factory" "github.com/docker/docker-registry/configuration" "github.com/docker/docker-registry/storage" log "github.com/Sirupsen/logrus" "github.com/gorilla/mux" ) // App is a global registry application object. Shared resources can be placed // on this object that will be accessible from all requests. Any writable // fields should be protected. type App struct { Config configuration.Configuration router *mux.Router // driver maintains the app global storage driver instance. driver storagedriver.StorageDriver // services contains the main services instance for the application. services *storage.Services } // NewApp takes a configuration and returns a configured app, ready to serve // requests. The app only implements ServeHTTP and can be wrapped in other // handlers accordingly. func NewApp(configuration configuration.Configuration) *App { app := &App{ Config: configuration, router: v2APIRouter(), } // Register the handler dispatchers. app.register(routeNameImageManifest, imageManifestDispatcher) app.register(routeNameTags, tagsDispatcher) app.register(routeNameBlob, layerDispatcher) app.register(routeNameBlobUpload, layerUploadDispatcher) app.register(routeNameBlobUploadResume, layerUploadDispatcher) driver, err := factory.Create(configuration.Storage.Type(), configuration.Storage.Parameters()) if err != nil { // TODO(stevvooe): Move the creation of a service into a protected // method, where this is created lazily. Its status can be queried via // a health check. panic(err) } app.driver = driver app.services = storage.NewServices(app.driver) return app } func (app *App) ServeHTTP(w http.ResponseWriter, r *http.Request) { app.router.ServeHTTP(w, r) } // register a handler with the application, by route name. The handler will be // passed through the application filters and context will be constructed at // request time. func (app *App) register(routeName string, dispatch dispatchFunc) { // TODO(stevvooe): This odd dispatcher/route registration is by-product of // some limitations in the gorilla/mux router. We are using it to keep // routing consistent between the client and server, but we may want to // replace it with manual routing and structure-based dispatch for better // control over the request execution. app.router.GetRoute(routeName).Handler(app.dispatcher(dispatch)) } // dispatchFunc takes a context and request and returns a constructed handler // for the route. The dispatcher will use this to dynamically create request // specific handlers for each endpoint without creating a new router for each // request. type dispatchFunc func(ctx *Context, r *http.Request) http.Handler // TODO(stevvooe): dispatchers should probably have some validation error // chain with proper error reporting. // singleStatusResponseWriter only allows the first status to be written to be // the valid request status. The current use case of this class should be // factored out. type singleStatusResponseWriter struct { http.ResponseWriter status int } func (ssrw *singleStatusResponseWriter) WriteHeader(status int) { if ssrw.status != 0 { return } ssrw.status = status ssrw.ResponseWriter.WriteHeader(status) } // dispatcher returns a handler that constructs a request specific context and // handler, using the dispatch factory function. func (app *App) dispatcher(dispatch dispatchFunc) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { vars := mux.Vars(r) context := &Context{ App: app, Name: vars["name"], } // Store vars for underlying handlers. context.vars = vars context.log = log.WithField("name", context.Name) handler := dispatch(context, r) ssrw := &singleStatusResponseWriter{ResponseWriter: w} context.log.Infoln("handler", resolveHandlerName(r.Method, handler)) handler.ServeHTTP(ssrw, r) // Automated error response handling here. Handlers may return their // own errors if they need different behavior (such as range errors // for layer upload). if context.Errors.Len() > 0 { if ssrw.status == 0 { w.WriteHeader(http.StatusBadRequest) } serveJSON(w, context.Errors) } }) }