| package server // import "github.com/docker/docker/api/server" |
| |
| import ( |
| "context" |
| "crypto/tls" |
| "net" |
| "net/http" |
| "strings" |
| |
| "github.com/docker/docker/api/server/httputils" |
| "github.com/docker/docker/api/server/middleware" |
| "github.com/docker/docker/api/server/router" |
| "github.com/docker/docker/api/server/router/debug" |
| "github.com/docker/docker/dockerversion" |
| "github.com/docker/docker/errdefs" |
| "github.com/gorilla/mux" |
| "github.com/sirupsen/logrus" |
| ) |
| |
| // versionMatcher defines a variable matcher to be parsed by the router |
| // when a request is about to be served. |
| const versionMatcher = "/v{version:[0-9.]+}" |
| |
| // Config provides the configuration for the API server |
| type Config struct { |
| Logging bool |
| CorsHeaders string |
| Version string |
| SocketGroup string |
| TLSConfig *tls.Config |
| } |
| |
| // Server contains instance details for the server |
| type Server struct { |
| cfg *Config |
| servers []*HTTPServer |
| routers []router.Router |
| routerSwapper *routerSwapper |
| middlewares []middleware.Middleware |
| } |
| |
| // New returns a new instance of the server based on the specified configuration. |
| // It allocates resources which will be needed for ServeAPI(ports, unix-sockets). |
| func New(cfg *Config) *Server { |
| return &Server{ |
| cfg: cfg, |
| } |
| } |
| |
| // UseMiddleware appends a new middleware to the request chain. |
| // This needs to be called before the API routes are configured. |
| func (s *Server) UseMiddleware(m middleware.Middleware) { |
| s.middlewares = append(s.middlewares, m) |
| } |
| |
| // Accept sets a listener the server accepts connections into. |
| func (s *Server) Accept(addr string, listeners ...net.Listener) { |
| for _, listener := range listeners { |
| httpServer := &HTTPServer{ |
| srv: &http.Server{ |
| Addr: addr, |
| }, |
| l: listener, |
| } |
| s.servers = append(s.servers, httpServer) |
| } |
| } |
| |
| // Close closes servers and thus stop receiving requests |
| func (s *Server) Close() { |
| for _, srv := range s.servers { |
| if err := srv.Close(); err != nil { |
| logrus.Error(err) |
| } |
| } |
| } |
| |
| // serveAPI loops through all initialized servers and spawns goroutine |
| // with Serve method for each. It sets createMux() as Handler also. |
| func (s *Server) serveAPI() error { |
| var chErrors = make(chan error, len(s.servers)) |
| for _, srv := range s.servers { |
| srv.srv.Handler = s.routerSwapper |
| go func(srv *HTTPServer) { |
| var err error |
| logrus.Infof("API listen on %s", srv.l.Addr()) |
| if err = srv.Serve(); err != nil && strings.Contains(err.Error(), "use of closed network connection") { |
| err = nil |
| } |
| chErrors <- err |
| }(srv) |
| } |
| |
| for range s.servers { |
| err := <-chErrors |
| if err != nil { |
| return err |
| } |
| } |
| return nil |
| } |
| |
| // HTTPServer contains an instance of http server and the listener. |
| // srv *http.Server, contains configuration to create an http server and a mux router with all api end points. |
| // l net.Listener, is a TCP or Socket listener that dispatches incoming request to the router. |
| type HTTPServer struct { |
| srv *http.Server |
| l net.Listener |
| } |
| |
| // Serve starts listening for inbound requests. |
| func (s *HTTPServer) Serve() error { |
| return s.srv.Serve(s.l) |
| } |
| |
| // Close closes the HTTPServer from listening for the inbound requests. |
| func (s *HTTPServer) Close() error { |
| return s.l.Close() |
| } |
| |
| func (s *Server) makeHTTPHandler(handler httputils.APIFunc) http.HandlerFunc { |
| return func(w http.ResponseWriter, r *http.Request) { |
| // Define the context that we'll pass around to share info |
| // like the docker-request-id. |
| // |
| // The 'context' will be used for global data that should |
| // apply to all requests. Data that is specific to the |
| // immediate function being called should still be passed |
| // as 'args' on the function call. |
| |
| // use intermediate variable to prevent "should not use basic type |
| // string as key in context.WithValue" golint errors |
| ctx := context.WithValue(r.Context(), dockerversion.UAStringKey{}, r.Header.Get("User-Agent")) |
| r = r.WithContext(ctx) |
| handlerFunc := s.handlerWithGlobalMiddlewares(handler) |
| |
| vars := mux.Vars(r) |
| if vars == nil { |
| vars = make(map[string]string) |
| } |
| |
| if err := handlerFunc(ctx, w, r, vars); err != nil { |
| statusCode := errdefs.GetHTTPErrorStatusCode(err) |
| if statusCode >= 500 { |
| logrus.Errorf("Handler for %s %s returned error: %v", r.Method, r.URL.Path, err) |
| } |
| httputils.MakeErrorHandler(err)(w, r) |
| } |
| } |
| } |
| |
| // InitRouter initializes the list of routers for the server. |
| // This method also enables the Go profiler. |
| func (s *Server) InitRouter(routers ...router.Router) { |
| s.routers = append(s.routers, routers...) |
| |
| m := s.createMux() |
| s.routerSwapper = &routerSwapper{ |
| router: m, |
| } |
| } |
| |
| type pageNotFoundError struct{} |
| |
| func (pageNotFoundError) Error() string { |
| return "page not found" |
| } |
| |
| func (pageNotFoundError) NotFound() {} |
| |
| // createMux initializes the main router the server uses. |
| func (s *Server) createMux() *mux.Router { |
| m := mux.NewRouter() |
| |
| logrus.Debug("Registering routers") |
| for _, apiRouter := range s.routers { |
| for _, r := range apiRouter.Routes() { |
| f := s.makeHTTPHandler(r.Handler()) |
| |
| logrus.Debugf("Registering %s, %s", r.Method(), r.Path()) |
| m.Path(versionMatcher + r.Path()).Methods(r.Method()).Handler(f) |
| m.Path(r.Path()).Methods(r.Method()).Handler(f) |
| } |
| } |
| |
| debugRouter := debug.NewRouter() |
| s.routers = append(s.routers, debugRouter) |
| for _, r := range debugRouter.Routes() { |
| f := s.makeHTTPHandler(r.Handler()) |
| m.Path("/debug" + r.Path()).Handler(f) |
| } |
| |
| notFoundHandler := httputils.MakeErrorHandler(pageNotFoundError{}) |
| m.HandleFunc(versionMatcher+"/{path:.*}", notFoundHandler) |
| m.NotFoundHandler = notFoundHandler |
| m.MethodNotAllowedHandler = notFoundHandler |
| |
| return m |
| } |
| |
| // Wait blocks the server goroutine until it exits. |
| // It sends an error message if there is any error during |
| // the API execution. |
| func (s *Server) Wait(waitChan chan error) { |
| if err := s.serveAPI(); err != nil { |
| logrus.Errorf("ServeAPI error: %v", err) |
| waitChan <- err |
| return |
| } |
| waitChan <- nil |
| } |