package registry import ( "fmt" "net/http" "github.com/docker/distribution/api/v2" "github.com/docker/distribution/auth" "github.com/docker/distribution/configuration" "github.com/docker/distribution/storage" "github.com/docker/distribution/storagedriver" "github.com/docker/distribution/storagedriver/factory" 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 // registry is the primary registry backend for the app instance. registry storage.Registry layerHandler storage.LayerHandler accessController auth.AccessController } // 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: v2.Router(), } // Register the handler dispatchers. app.register(v2.RouteNameBase, func(ctx *Context, r *http.Request) http.Handler { return http.HandlerFunc(apiBase) }) app.register(v2.RouteNameManifest, imageManifestDispatcher) app.register(v2.RouteNameTags, tagsDispatcher) app.register(v2.RouteNameBlob, layerDispatcher) app.register(v2.RouteNameBlobUpload, layerUploadDispatcher) app.register(v2.RouteNameBlobUploadChunk, 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.registry = storage.NewRegistryWithDriver(app.driver) authType := configuration.Auth.Type() if authType != "" { accessController, err := auth.GetAccessController(configuration.Auth.Type(), configuration.Auth.Parameters()) if err != nil { panic(fmt.Sprintf("unable to configure authorization (%s): %v", authType, err)) } app.accessController = accessController } layerHandlerType := configuration.LayerHandler.Type() if layerHandlerType != "" { lh, err := storage.GetLayerHandler(layerHandlerType, configuration.LayerHandler.Parameters(), driver) if err != nil { panic(fmt.Sprintf("unable to configure layer handler (%s): %v", layerHandlerType, err)) } app.layerHandler = lh } return app } func (app *App) ServeHTTP(w http.ResponseWriter, r *http.Request) { // Set a header with the Docker Distribution API Version for all responses. w.Header().Add("Docker-Distribution-API-Version", "registry/2.0") 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) { context := app.context(r) if err := app.authorized(w, r, context, context.vars["name"]); err != nil { return } context.log = log.WithField("name", context.Repository.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) } }) } // context constructs the context object for the application. This only be // called once per request. func (app *App) context(r *http.Request) *Context { vars := mux.Vars(r) context := &Context{ App: app, urlBuilder: v2.NewURLBuilderFromRequest(r), } // Store vars for underlying handlers. context.vars = vars return context } // authorized checks if the request can proceed with access to the requested // repository. If it succeeds, the repository will be available on the // context. An error will be if access is not available. func (app *App) authorized(w http.ResponseWriter, r *http.Request, context *Context, repo string) error { if app.accessController == nil { // No access controller, so we simply provide access. context.Repository = app.registry.Repository(repo) return nil // access controller is not enabled. } var accessRecords []auth.Access if repo != "" { resource := auth.Resource{ Type: "repository", Name: repo, } switch r.Method { case "GET", "HEAD": accessRecords = append(accessRecords, auth.Access{ Resource: resource, Action: "pull", }) case "POST", "PUT", "PATCH": accessRecords = append(accessRecords, auth.Access{ Resource: resource, Action: "pull", }, auth.Access{ Resource: resource, Action: "push", }) case "DELETE": // DELETE access requires full admin rights, which is represented // as "*". This may not be ideal. accessRecords = append(accessRecords, auth.Access{ Resource: resource, Action: "*", }) } } else { // Only allow the name not to be set on the base route. route := mux.CurrentRoute(r) if route == nil || route.GetName() != v2.RouteNameBase { // For this to be properly secured, context.Name must always be set // for a resource that may make a modification. The only condition // under which name is not set and we still allow access is when the // base route is accessed. This section prevents us from making that // mistake elsewhere in the code, allowing any operation to proceed. w.Header().Set("Content-Type", "application/json; charset=utf-8") w.WriteHeader(http.StatusForbidden) var errs v2.Errors errs.Push(v2.ErrorCodeUnauthorized) serveJSON(w, errs) } } if err := app.accessController.Authorized(r, accessRecords...); err != nil { switch err := err.(type) { case auth.Challenge: w.Header().Set("Content-Type", "application/json; charset=utf-8") err.ServeHTTP(w, r) var errs v2.Errors errs.Push(v2.ErrorCodeUnauthorized, accessRecords) serveJSON(w, errs) default: // This condition is a potential security problem either in // the configuration or whatever is backing the access // controller. Just return a bad request with no information // to avoid exposure. The request should not proceed. context.log.Errorf("error checking authorization: %v", err) w.WriteHeader(http.StatusBadRequest) } return err } // At this point, the request should have access to the repository under // the requested operation. Make is available on the context. context.Repository = app.registry.Repository(repo) return nil } // apiBase implements a simple yes-man for doing overall checks against the // api. This can support auth roundtrips to support docker login. func apiBase(w http.ResponseWriter, r *http.Request) { const emptyJSON = "{}" // Provide a simple /v2/ 200 OK response with empty json response. w.Header().Set("Content-Type", "application/json; charset=utf-8") w.Header().Set("Content-Length", fmt.Sprint(len(emptyJSON))) fmt.Fprint(w, emptyJSON) }