package handlers import ( "fmt" "net" "net/http" "os" "code.google.com/p/go-uuid/uuid" "github.com/docker/distribution/api/v2" "github.com/docker/distribution/auth" "github.com/docker/distribution/configuration" ctxu "github.com/docker/distribution/context" "github.com/docker/distribution/storage" "github.com/docker/distribution/storage/notifications" "github.com/docker/distribution/storagedriver" "github.com/docker/distribution/storagedriver/factory" "github.com/gorilla/mux" "golang.org/x/net/context" ) // 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 { context.Context Config configuration.Configuration // InstanceID is a unique id assigned to the application on each creation. // Provides information in the logs and context to identify restarts. InstanceID string router *mux.Router // main application router, configured with dispatchers driver storagedriver.StorageDriver // driver maintains the app global storage driver instance. registry storage.Registry // registry is the primary registry backend for the app instance. accessController auth.AccessController // main access controller for application // events contains notification related configuration. events struct { sink notifications.Sink source notifications.SourceRecord } layerHandler storage.LayerHandler // allows dispatch of layer serving to external provider } // Value intercepts calls context.Context.Value, returning the current app id, // if requested. func (app *App) Value(key interface{}) interface{} { switch key { case "app.id": return app.InstanceID } return app.Context.Value(key) } // 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(ctx context.Context, configuration configuration.Configuration) *App { app := &App{ Config: configuration, Context: ctx, InstanceID: uuid.New(), router: v2.Router(), } app.Context = ctxu.WithLogger(app.Context, ctxu.GetLogger(app, "app.id")) // 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) var err error app.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.configureEvents(&configuration) 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(), app.driver) if err != nil { panic(fmt.Sprintf("unable to configure layer handler (%s): %v", layerHandlerType, err)) } app.layerHandler = lh } return app } // 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)) } // configureEvents prepares the event sink for action. func (app *App) configureEvents(configuration *configuration.Configuration) { // Configure all of the endpoint sinks. var sinks []notifications.Sink for _, endpoint := range configuration.Notifications.Endpoints { if endpoint.Disabled { ctxu.GetLogger(app).Infof("endpoint %s disabled, skipping", endpoint.Name) continue } ctxu.GetLogger(app).Infof("configuring endpoint %v (%v), timeout=%s, headers=%v", endpoint.Name, endpoint.URL, endpoint.Timeout, endpoint.Headers) endpoint := notifications.NewEndpoint(endpoint.Name, endpoint.URL, notifications.EndpointConfig{ Timeout: endpoint.Timeout, Threshold: endpoint.Threshold, Backoff: endpoint.Backoff, Headers: endpoint.Headers, }) sinks = append(sinks, endpoint) } // NOTE(stevvooe): Moving to a new queueing implementation is as easy as // replacing broadcaster with a rabbitmq implementation. It's recommended // that the registry instances also act as the workers to keep deployment // simple. app.events.sink = notifications.NewBroadcaster(sinks...) // Populate registry event source hostname, err := os.Hostname() if err != nil { hostname = configuration.HTTP.Addr } else { // try to pick the port off the config _, port, err := net.SplitHostPort(configuration.HTTP.Addr) if err == nil { hostname = net.JoinHostPort(hostname, port) } } app.events.source = notifications.SourceRecord{ Addr: hostname, InstanceID: app.InstanceID, } } func (app *App) ServeHTTP(w http.ResponseWriter, r *http.Request) { defer r.Body.Close() // ensure that request body is always closed. // 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) } // 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) } func (ssrw *singleStatusResponseWriter) Flush() { if flusher, ok := ssrw.ResponseWriter.(http.Flusher); ok { flusher.Flush() } } // 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(w, r) defer func() { ctxu.GetResponseLogger(context).Infof("response completed") }() if err := app.authorized(w, r, context); err != nil { ctxu.GetLogger(context).Errorf("error authorizing context: %v", err) return } // decorate the authorized repository with an event bridge. context.Repository = notifications.Listen( app.registry.Repository(context, getName(context)), app.eventBridge(context, r)) handler := dispatch(context, r) ssrw := &singleStatusResponseWriter{ResponseWriter: w} 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(w http.ResponseWriter, r *http.Request) *Context { ctx := ctxu.WithRequest(app, r) ctx, w = ctxu.WithResponseWriter(ctx, w) ctx = ctxu.WithVars(ctx, r) ctx = ctxu.WithLogger(ctx, ctxu.GetRequestLogger(ctx)) ctx = ctxu.WithLogger(ctx, ctxu.GetLogger(ctx, "vars.name", "vars.tag", "vars.digest", "vars.tag", "vars.uuid")) context := &Context{ App: app, Context: ctx, urlBuilder: v2.NewURLBuilderFromRequest(r), } return context } // authorized checks if the request can proceed with access to the requested // repository. If it succeeds, the context may access the requested // repository. An error will be returned if access is not available. func (app *App) authorized(w http.ResponseWriter, r *http.Request, context *Context) error { ctxu.GetLogger(context).Debug("authorizing request") repo := getName(context) if app.accessController == nil { 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, repo 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) return fmt.Errorf("forbidden: no repository name") } } ctx, err := app.accessController.Authorized(context.Context, accessRecords...) if 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. ctxu.GetLogger(context).Errorf("error checking authorization: %v", err) w.WriteHeader(http.StatusBadRequest) } return err } // TODO(stevvooe): This pattern needs to be cleaned up a bit. One context // should be replaced by another, rather than replacing the context on a // mutable object. context.Context = ctx return nil } // eventBridge returns a bridge for the current request, configured with the // correct actor and source. func (app *App) eventBridge(ctx *Context, r *http.Request) notifications.Listener { actor := notifications.ActorRecord{ Name: getUserName(ctx, r), } request := notifications.NewRequestRecord(ctxu.GetRequestID(ctx), r) return notifications.NewBridge(ctx.urlBuilder, app.events.source, actor, request, app.events.sink) } // 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) }