1package server 2 3import ( 4 "crypto/tls" 5 "net" 6 "net/http" 7 "strings" 8 9 "github.com/docker/docker/api/server/httputils" 10 "github.com/docker/docker/api/server/middleware" 11 "github.com/docker/docker/api/server/router" 12 "github.com/docker/docker/api/server/router/debug" 13 "github.com/docker/docker/dockerversion" 14 "github.com/gorilla/mux" 15 "github.com/sirupsen/logrus" 16 "golang.org/x/net/context" 17) 18 19// versionMatcher defines a variable matcher to be parsed by the router 20// when a request is about to be served. 21const versionMatcher = "/v{version:[0-9.]+}" 22 23// Config provides the configuration for the API server 24type Config struct { 25 Logging bool 26 CorsHeaders string 27 Version string 28 SocketGroup string 29 TLSConfig *tls.Config 30} 31 32// Server contains instance details for the server 33type Server struct { 34 cfg *Config 35 servers []*HTTPServer 36 routers []router.Router 37 routerSwapper *routerSwapper 38 middlewares []middleware.Middleware 39} 40 41// New returns a new instance of the server based on the specified configuration. 42// It allocates resources which will be needed for ServeAPI(ports, unix-sockets). 43func New(cfg *Config) *Server { 44 return &Server{ 45 cfg: cfg, 46 } 47} 48 49// UseMiddleware appends a new middleware to the request chain. 50// This needs to be called before the API routes are configured. 51func (s *Server) UseMiddleware(m middleware.Middleware) { 52 s.middlewares = append(s.middlewares, m) 53} 54 55// Accept sets a listener the server accepts connections into. 56func (s *Server) Accept(addr string, listeners ...net.Listener) { 57 for _, listener := range listeners { 58 httpServer := &HTTPServer{ 59 srv: &http.Server{ 60 Addr: addr, 61 }, 62 l: listener, 63 } 64 s.servers = append(s.servers, httpServer) 65 } 66} 67 68// Close closes servers and thus stop receiving requests 69func (s *Server) Close() { 70 for _, srv := range s.servers { 71 if err := srv.Close(); err != nil { 72 logrus.Error(err) 73 } 74 } 75} 76 77// serveAPI loops through all initialized servers and spawns goroutine 78// with Serve method for each. It sets createMux() as Handler also. 79func (s *Server) serveAPI() error { 80 var chErrors = make(chan error, len(s.servers)) 81 for _, srv := range s.servers { 82 srv.srv.Handler = s.routerSwapper 83 go func(srv *HTTPServer) { 84 var err error 85 logrus.Infof("API listen on %s", srv.l.Addr()) 86 if err = srv.Serve(); err != nil && strings.Contains(err.Error(), "use of closed network connection") { 87 err = nil 88 } 89 chErrors <- err 90 }(srv) 91 } 92 93 for range s.servers { 94 err := <-chErrors 95 if err != nil { 96 return err 97 } 98 } 99 return nil 100} 101 102// HTTPServer contains an instance of http server and the listener. 103// srv *http.Server, contains configuration to create an http server and a mux router with all api end points. 104// l net.Listener, is a TCP or Socket listener that dispatches incoming request to the router. 105type HTTPServer struct { 106 srv *http.Server 107 l net.Listener 108} 109 110// Serve starts listening for inbound requests. 111func (s *HTTPServer) Serve() error { 112 return s.srv.Serve(s.l) 113} 114 115// Close closes the HTTPServer from listening for the inbound requests. 116func (s *HTTPServer) Close() error { 117 return s.l.Close() 118} 119 120func (s *Server) makeHTTPHandler(handler httputils.APIFunc) http.HandlerFunc { 121 return func(w http.ResponseWriter, r *http.Request) { 122 // Define the context that we'll pass around to share info 123 // like the docker-request-id. 124 // 125 // The 'context' will be used for global data that should 126 // apply to all requests. Data that is specific to the 127 // immediate function being called should still be passed 128 // as 'args' on the function call. 129 ctx := context.WithValue(context.Background(), dockerversion.UAStringKey, r.Header.Get("User-Agent")) 130 handlerFunc := s.handlerWithGlobalMiddlewares(handler) 131 132 vars := mux.Vars(r) 133 if vars == nil { 134 vars = make(map[string]string) 135 } 136 137 if err := handlerFunc(ctx, w, r, vars); err != nil { 138 statusCode := httputils.GetHTTPErrorStatusCode(err) 139 if statusCode >= 500 { 140 logrus.Errorf("Handler for %s %s returned error: %v", r.Method, r.URL.Path, err) 141 } 142 httputils.MakeErrorHandler(err)(w, r) 143 } 144 } 145} 146 147// InitRouter initializes the list of routers for the server. 148// This method also enables the Go profiler if enableProfiler is true. 149func (s *Server) InitRouter(routers ...router.Router) { 150 s.routers = append(s.routers, routers...) 151 152 m := s.createMux() 153 s.routerSwapper = &routerSwapper{ 154 router: m, 155 } 156} 157 158type pageNotFoundError struct{} 159 160func (pageNotFoundError) Error() string { 161 return "page not found" 162} 163 164func (pageNotFoundError) NotFound() {} 165 166// createMux initializes the main router the server uses. 167func (s *Server) createMux() *mux.Router { 168 m := mux.NewRouter() 169 170 logrus.Debug("Registering routers") 171 for _, apiRouter := range s.routers { 172 for _, r := range apiRouter.Routes() { 173 f := s.makeHTTPHandler(r.Handler()) 174 175 logrus.Debugf("Registering %s, %s", r.Method(), r.Path()) 176 m.Path(versionMatcher + r.Path()).Methods(r.Method()).Handler(f) 177 m.Path(r.Path()).Methods(r.Method()).Handler(f) 178 } 179 } 180 181 debugRouter := debug.NewRouter() 182 s.routers = append(s.routers, debugRouter) 183 for _, r := range debugRouter.Routes() { 184 f := s.makeHTTPHandler(r.Handler()) 185 m.Path("/debug" + r.Path()).Handler(f) 186 } 187 188 notFoundHandler := httputils.MakeErrorHandler(pageNotFoundError{}) 189 m.HandleFunc(versionMatcher+"/{path:.*}", notFoundHandler) 190 m.NotFoundHandler = notFoundHandler 191 192 return m 193} 194 195// Wait blocks the server goroutine until it exits. 196// It sends an error message if there is any error during 197// the API execution. 198func (s *Server) Wait(waitChan chan error) { 199 if err := s.serveAPI(); err != nil { 200 logrus.Errorf("ServeAPI error: %v", err) 201 waitChan <- err 202 return 203 } 204 waitChan <- nil 205} 206