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| 1 // Copyright 2015 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 package epfrontend | |
| 6 | |
| 7 import ( | |
| 8 "bytes" | |
| 9 "encoding/json" | |
| 10 "fmt" | |
| 11 "io/ioutil" | |
| 12 "net/http" | |
| 13 "strconv" | |
| 14 "strings" | |
| 15 | |
| 16 "github.com/GoogleCloudPlatform/go-endpoints/endpoints" | |
| 17 "github.com/luci/luci-go/common/logging" | |
| 18 "github.com/luci/luci-go/common/paniccatcher" | |
| 19 ) | |
| 20 | |
| 21 const ( | |
| 22 // DefaultServerRoot is the default Server root value. | |
| 23 DefaultServerRoot = "/_ah/api/" | |
| 24 ) | |
| 25 | |
| 26 var ( | |
| 27 errMethodNotAllowed = endpoints.NewAPIError(http.StatusText(http.StatusM
ethodNotAllowed), | |
| 28 "", http.StatusMethodNotAllowed) | |
| 29 ) | |
| 30 | |
| 31 type handlerFuncWithError func(http.ResponseWriter, *http.Request) error | |
| 32 | |
| 33 // endpoint is a resolved backend endpoint. | |
| 34 type endpoint struct { | |
| 35 // desc is the resolved service descriptor. | |
| 36 desc *endpoints.APIDescriptor | |
| 37 // method is the resolved method within the service. | |
| 38 method *endpoints.APIMethod | |
| 39 // backendPath is the backend path of this method. | |
| 40 backendPath string | |
| 41 } | |
| 42 | |
| 43 type endpointNode struct { | |
| 44 // parent points to this endpointNode's parent node. If nil, this is the | |
| 45 // root endpoint node. | |
| 46 parent *endpointNode | |
| 47 | |
| 48 // component is the path component's value. | |
| 49 // | |
| 50 // If this is an empty string, this is a query parameter component. | |
| 51 component string | |
| 52 // paramName is the query parameter name for this node. It is valid if | |
| 53 // component is "". | |
| 54 paramName string | |
| 55 // ep is the endpoint attached to this node. It can be nil if no endpoin
t is | |
| 56 // attached. | |
| 57 ep *endpoint | |
| 58 | |
| 59 children map[string]*endpointNode | |
| 60 } | |
| 61 | |
| 62 func (n *endpointNode) addChild(components []string, ep *endpoint) error { | |
| 63 comp := components[0] | |
| 64 paramName := "" | |
| 65 | |
| 66 if strings.HasPrefix(comp, "{") && strings.HasSuffix(comp, "}") { | |
| 67 // Replace query parameter with empty string. | |
| 68 paramName = comp[1 : len(comp)-1] | |
| 69 comp = "" | |
| 70 } | |
| 71 | |
| 72 child := n.children[comp] | |
| 73 if child == nil { | |
| 74 if n.children == nil { | |
| 75 n.children = map[string]*endpointNode{} | |
| 76 } | |
| 77 | |
| 78 child = &endpointNode{ | |
| 79 parent: n, | |
| 80 component: comp, | |
| 81 paramName: paramName, | |
| 82 } | |
| 83 n.children[child.component] = child | |
| 84 } | |
| 85 | |
| 86 if len(components) > 1 { | |
| 87 return child.addChild(components[1:], ep) | |
| 88 } | |
| 89 | |
| 90 child.ep = ep | |
| 91 return nil | |
| 92 } | |
| 93 | |
| 94 func (n *endpointNode) lookup(components ...string) *endpointNode { | |
| 95 if len(components) == 0 { | |
| 96 if n.ep == nil { | |
| 97 // Not a leaf node! | |
| 98 return nil | |
| 99 } | |
| 100 return n | |
| 101 } | |
| 102 | |
| 103 // Is this node parent to a query parameter? | |
| 104 if child := n.children[""]; child != nil { | |
| 105 // Assume that this component is a query parameter. Can we resol
ve against | |
| 106 // the remainder of the tree? | |
| 107 if cn := child.lookup(components[1:]...); cn != nil { | |
| 108 return cn | |
| 109 } | |
| 110 } | |
| 111 | |
| 112 // Use this node as a direct value. | |
| 113 if child := n.children[components[0]]; child != nil { | |
| 114 return child.lookup(components[1:]...) | |
| 115 } | |
| 116 return nil | |
| 117 } | |
| 118 | |
| 119 // serviceCall is a stateful structure that will be populated with the service | |
| 120 // call's parameters as they are resolved. | |
| 121 type serviceCall struct { | |
| 122 // path is the initial service call path. | |
| 123 path string | |
| 124 | |
| 125 // ep is the resolved endpoint description for this call. | |
| 126 ep *endpoint | |
| 127 // params is the map of key/value query parameters populated during | |
| 128 // resolution. | |
| 129 params map[string]interface{} | |
| 130 } | |
| 131 | |
| 132 func (c *serviceCall) addParam(k string, v interface{}) { | |
| 133 if c.params == nil { | |
| 134 c.params = map[string]interface{}{} | |
| 135 } | |
| 136 c.params[k] = v | |
| 137 } | |
| 138 | |
| 139 // Server is an HTTP handler | |
| 140 type Server struct { | |
| 141 // Logger is a function that is called to obtain a logger for the curren
t | |
| 142 // http.Request. Logger will be called with a nil http.Request when a lo
gger | |
| 143 // is needed outside of the scope of request handling. | |
| 144 // | |
| 145 // If Logger is nil, or if Logger returns nil, a logging.Null logger wil
l be | |
| 146 // used. | |
| 147 Logger func(*http.Request) logging.Logger | |
| 148 | |
| 149 // root is the root path of this Server. | |
| 150 root string | |
| 151 // backend is the endpoints Server instance to bind to. | |
| 152 backend http.Handler | |
| 153 // logger is the resolved no-context logger. | |
| 154 logger logging.Logger | |
| 155 // endpoints is a map of method to endpoint path component tree. | |
| 156 endpoints map[string]*endpointNode | |
| 157 // services is a map of registered services. | |
| 158 services map[string]*endpoints.APIDescriptor | |
| 159 // paths is a map of direct paths and their handler functions. | |
| 160 paths map[string]handlerFuncWithError | |
| 161 } | |
| 162 | |
| 163 // New instantiates a new Server instance. | |
| 164 // | |
| 165 // If root is the empty string, DefaultServerRoot will be used. | |
| 166 // If backend is nil, endpoints.DefaultServer will be used. | |
| 167 func New(root string, backend http.Handler) *Server { | |
| 168 if root == "" { | |
| 169 root = DefaultServerRoot | |
| 170 } | |
| 171 if backend == nil { | |
| 172 backend = endpoints.DefaultServer | |
| 173 } | |
| 174 | |
| 175 s := &Server{ | |
| 176 root: root, | |
| 177 backend: backend, | |
| 178 } | |
| 179 s.logger = s.getLogger(nil) | |
| 180 | |
| 181 s.registerPath(safeURLPathJoin("discovery", "v1", "apis"), s.serveGetJSO
N(s.handleDirectoryList)) | |
| 182 s.registerPath(safeURLPathJoin("explorer"), func(w http.ResponseWriter,
r *http.Request) error { | |
| 183 http.Redirect(w, r, fmt.Sprintf("http://apis-explorer.appspot.co
m/apis-explorer/?base=%s", | |
| 184 safeURLPathJoin(getHostURL(r).String(), s.root)), http.S
tatusFound) | |
| 185 return nil | |
| 186 }) | |
| 187 return s | |
| 188 } | |
| 189 | |
| 190 // RegisterService registers an endpoints service's descriptor with the Server. | |
| 191 func (s *Server) RegisterService(svc *endpoints.RPCService) error { | |
| 192 desc := endpoints.APIDescriptor{} | |
| 193 if err := svc.APIDescriptor(&desc, "epfrontend"); err != nil { | |
| 194 return err | |
| 195 } | |
| 196 if _, ok := s.services[desc.Name]; ok { | |
| 197 return fmt.Errorf("service [%s] already registered", desc.Name) | |
| 198 } | |
| 199 if s.services == nil { | |
| 200 s.services = map[string]*endpoints.APIDescriptor{} | |
| 201 } | |
| 202 s.services[desc.Name] = &desc | |
| 203 | |
| 204 // Traverse the method map. | |
| 205 apibase := []string{desc.Name, desc.Version} | |
| 206 for _, m := range desc.Methods { | |
| 207 // Build our API path: service/version / method/path/components | |
| 208 parts := strings.Split(m.Path, "/") | |
| 209 apipath := make([]string, 0, len(apibase)+len(parts)) | |
| 210 apipath = append(apipath, apibase...) | |
| 211 apipath = append(apipath, parts...) | |
| 212 | |
| 213 ep := endpoint{ | |
| 214 desc: &desc, | |
| 215 method: m, | |
| 216 backendPath: m.RosyMethod, | |
| 217 } | |
| 218 if err := s.registerEndpoint(m.HTTPMethod, apipath, &ep); err !=
nil { | |
| 219 return err | |
| 220 } | |
| 221 } | |
| 222 | |
| 223 s.registerPath(safeURLPathJoin("discovery", "v1", "apis", desc.Name, des
c.Version, "rest"), | |
| 224 s.serveGetJSON(func(r *http.Request) (interface{}, error) { | |
| 225 return s.handleRestDescription(r, &desc) | |
| 226 })) | |
| 227 return nil | |
| 228 } | |
| 229 | |
| 230 func (s *Server) registerEndpoint(method string, apipath []string, ep *endpoint)
error { | |
| 231 s.logger.Debugf("Registering %s %s => %#v", method, apipath, ep) | |
| 232 if s.endpoints == nil { | |
| 233 s.endpoints = map[string]*endpointNode{} | |
| 234 } | |
| 235 | |
| 236 methodNode := s.endpoints[method] | |
| 237 if methodNode == nil { | |
| 238 methodNode = &endpointNode{} | |
| 239 s.endpoints[method] = methodNode | |
| 240 } | |
| 241 | |
| 242 if n := methodNode.lookup(apipath...); n != nil { | |
| 243 return fmt.Errorf("%s method [%s] is already registered", method
, apipath) | |
| 244 } | |
| 245 return methodNode.addChild(apipath, ep) | |
| 246 } | |
| 247 | |
| 248 func (s *Server) registerPath(path string, handler handlerFuncWithError) { | |
| 249 if s.paths == nil { | |
| 250 s.paths = map[string]handlerFuncWithError{} | |
| 251 } | |
| 252 s.paths[path] = handler | |
| 253 } | |
| 254 | |
| 255 // HandleHTTP adds Server s to specified http.ServeMux. | |
| 256 // If no mux is provided, http.DefaultServeMux will be used. | |
| 257 func (s *Server) HandleHTTP(mux *http.ServeMux) { | |
| 258 if mux == nil { | |
| 259 mux = http.DefaultServeMux | |
| 260 } | |
| 261 mux.Handle(s.root, s) | |
| 262 } | |
| 263 | |
| 264 // ServeHTTP is the Server's implementation of the http.Handler interface. | |
| 265 func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) { | |
| 266 h := requestHandler{ | |
| 267 Server: s, | |
| 268 logger: s.getLogger(r), | |
| 269 } | |
| 270 h.handle(w, r) | |
| 271 } | |
| 272 | |
| 273 // serveGetJSON returns an HTTP handler that serves the marshalled JSON form of | |
| 274 // the specified object. | |
| 275 func (s *Server) serveGetJSON(f func(*http.Request) (interface{}, error)) handle
rFuncWithError { | |
| 276 return func(w http.ResponseWriter, req *http.Request) error { | |
| 277 if req.Method != "GET" { | |
| 278 return errMethodNotAllowed | |
| 279 } | |
| 280 | |
| 281 i, err := f(req) | |
| 282 if err != nil { | |
| 283 return err | |
| 284 } | |
| 285 | |
| 286 data, err := json.MarshalIndent(i, "", " ") | |
| 287 if err != nil { | |
| 288 return err | |
| 289 } | |
| 290 | |
| 291 w.Header().Add("Content-Type", "application/json") | |
| 292 _, err = w.Write(data) | |
| 293 return err | |
| 294 } | |
| 295 } | |
| 296 | |
| 297 func (s *Server) getLogger(r *http.Request) (l logging.Logger) { | |
| 298 if s.Logger != nil { | |
| 299 l = s.Logger(r) | |
| 300 } | |
| 301 if l == nil { | |
| 302 l = logging.Null() | |
| 303 } | |
| 304 return | |
| 305 } | |
| 306 | |
| 307 type requestHandler struct { | |
| 308 *Server | |
| 309 | |
| 310 // logger shadows Server.logger and is bound to an http.Request. | |
| 311 logger logging.Logger | |
| 312 } | |
| 313 | |
| 314 func (h *requestHandler) handle(w http.ResponseWriter, r *http.Request) { | |
| 315 var err error | |
| 316 iw := &errorResponseWriter{ResponseWriter: w} | |
| 317 defer func() { | |
| 318 if err != nil { | |
| 319 iw.setError(err) | |
| 320 } | |
| 321 iw.forwardError() | |
| 322 }() | |
| 323 | |
| 324 paniccatcher.Do(func() { | |
| 325 err = h.handleImpl(iw, r) | |
| 326 }, func(p *paniccatcher.Panic) { | |
| 327 h.logger.Errorf("Panic during endpoint handling: %s\n%s", p.Reas
on, p.Stack) | |
| 328 err = endpoints.InternalServerError | |
| 329 }) | |
| 330 } | |
| 331 | |
| 332 func (h *requestHandler) handleImpl(w http.ResponseWriter, r *http.Request) erro
r { | |
| 333 if r.Body != nil { | |
| 334 defer r.Body.Close() | |
| 335 } | |
| 336 | |
| 337 // Strip our root from the request path, leaving the endpoint path. | |
| 338 if !strings.HasPrefix(r.URL.Path, h.root) { | |
| 339 h.logger.Debugf("Path (%s) does not begin with root (%s)", r.URL
.Path, h.root) | |
| 340 return endpoints.NotFoundError | |
| 341 } | |
| 342 path := strings.TrimPrefix(r.URL.Path, h.root) | |
| 343 h.logger.Debugf("Received HTTP %s request [%s]: [%s]", r.Method, r.URL.P
ath, path) | |
| 344 | |
| 345 // If we have an explicit path handler set up for this path, use it. | |
| 346 if ph := h.paths[path]; ph != nil { | |
| 347 return ph(w, r) | |
| 348 } | |
| 349 | |
| 350 // Resolve path to a service call. | |
| 351 call, err := h.resolveRequest(r.Method, path) | |
| 352 if err != nil { | |
| 353 h.logger.Warningf("Could not resolve %s request [%s] to a backen
d endpoint: %v", | |
| 354 r.Method, path, err) | |
| 355 return err | |
| 356 } | |
| 357 // Add query strings to call parameters. | |
| 358 for k, vs := range r.URL.Query() { | |
| 359 // If there are multiple values, add the last. | |
| 360 if len(vs) > 0 { | |
| 361 param := vs[len(vs)-1] | |
| 362 v, err := convertQueryParam(k, param, call.ep.method) | |
| 363 if err != nil { | |
| 364 h.logger.Errorf("Could not convert query param %
q (%q): %v", k, param, err) | |
| 365 return endpoints.BadRequestError | |
| 366 } | |
| 367 call.addParam(k, v) | |
| 368 } | |
| 369 } | |
| 370 h.logger.Debugf("Resolved %s request [%s] to endpoint [%s].", r.Method,
path, call.ep.backendPath) | |
| 371 | |
| 372 // Read the body for forwarding. | |
| 373 buf := bytes.Buffer{} | |
| 374 if _, err := buf.ReadFrom(r.Body); err != nil { | |
| 375 h.logger.Errorf("failed to read request body: %v", err) | |
| 376 return endpoints.InternalServerError | |
| 377 } | |
| 378 | |
| 379 // Replace the body with a JSON object, if necessary. | |
| 380 if buf.Len() == 0 || len(call.params) > 0 { | |
| 381 data := map[string]*jsonRWRawMessage{} | |
| 382 if buf.Len() > 0 { | |
| 383 if err := json.Unmarshal(buf.Bytes(), &data); err != nil
{ | |
| 384 h.logger.Errorf("Failed to unmarshal request JSO
N: %v", err) | |
| 385 return endpoints.BadRequestError | |
| 386 } | |
| 387 } | |
| 388 | |
| 389 for k, v := range call.params { | |
| 390 data[k] = &jsonRWRawMessage{ | |
| 391 v: v, | |
| 392 } | |
| 393 } | |
| 394 | |
| 395 buf.Reset() | |
| 396 m := json.NewEncoder(&buf) | |
| 397 if err := m.Encode(data); err != nil { | |
| 398 h.logger.Errorf("Failed to re-marshal request JSON: %v",
err) | |
| 399 return endpoints.InternalServerError | |
| 400 } | |
| 401 } | |
| 402 r.Body = ioutil.NopCloser(&buf) | |
| 403 | |
| 404 // Mutate our request to pretend it's a frontend-to-backend request, the
n | |
| 405 // forward it to the backend for actual API processing! | |
| 406 // | |
| 407 // The actual Path prefix doesn't matter, as the service only looks at t
he | |
| 408 // last component to derive the service call. | |
| 409 r.Method = "POST" | |
| 410 r.RequestURI = "/_ah/spi/" + call.ep.backendPath // Strips query paramet
ers. | |
| 411 r.URL.Path = r.RequestURI | |
| 412 h.backend.ServeHTTP(w, r) | |
| 413 return nil | |
| 414 } | |
| 415 | |
| 416 func (h *requestHandler) resolveRequest(method, path string) (*serviceCall, erro
r) { | |
| 417 call := serviceCall{ | |
| 418 path: path, | |
| 419 } | |
| 420 | |
| 421 parts := strings.Split(path, "/") | |
| 422 | |
| 423 h.logger.Debugf("Resolving %s request %s...", method, parts) | |
| 424 n := h.endpoints[method] | |
| 425 if n != nil { | |
| 426 n = n.lookup(parts...) | |
| 427 } | |
| 428 if n == nil { | |
| 429 return nil, endpoints.NotFoundError | |
| 430 } | |
| 431 ep := n.ep | |
| 432 call.ep = ep | |
| 433 | |
| 434 // Build our query parameters by reverse-traversing the tree towards its
root. | |
| 435 // | |
| 436 // The endpoints node path will have the same size as parts, since it ma
tched. | |
| 437 for len(parts) > 0 { | |
| 438 if n.paramName != "" { | |
| 439 param := parts[len(parts)-1] | |
| 440 v, err := convertQueryParam(n.paramName, param, ep.metho
d) | |
| 441 if err != nil { | |
| 442 h.logger.Errorf("Could not convert path param %q
(%q): %v", n.paramName, param, err) | |
| 443 return nil, endpoints.BadRequestError | |
| 444 } | |
| 445 call.addParam(n.paramName, v) | |
| 446 } | |
| 447 | |
| 448 parts = parts[:len(parts)-1] | |
| 449 n = n.parent | |
| 450 } | |
| 451 | |
| 452 return &call, nil | |
| 453 } | |
| 454 | |
| 455 func convertQueryParam(k, v string, m *endpoints.APIMethod) (interface{}, error)
{ | |
| 456 // Find the parameter for "k". | |
| 457 p := m.Request.Params[k] | |
| 458 if p == nil { | |
| 459 return v, nil | |
| 460 } | |
| 461 | |
| 462 switch p.Type { | |
| 463 case "int64", "uint64": | |
| 464 // Assume all int64 are "string"-quoted integers. If there are q
uotes, strip | |
| 465 // them. Return the result as a string. | |
| 466 if len(v) >= 2 && strings.HasPrefix(v, `"`) && strings.HasSuffix
(v, `"`) { | |
| 467 v = v[1 : len(v)-1] | |
| 468 } | |
| 469 if _, err := strconv.ParseInt(v, 10, 64); err != nil { | |
| 470 return nil, err | |
| 471 } | |
| 472 return v, nil | |
| 473 case "int32", "uint32": | |
| 474 return strconv.ParseInt(v, 10, 32) | |
| 475 case "float", "double": | |
| 476 return strconv.ParseFloat(v, 64) | |
| 477 case "boolean": | |
| 478 switch v { | |
| 479 case "", "false": | |
| 480 return false, nil | |
| 481 default: | |
| 482 return true, nil | |
| 483 } | |
| 484 case "string", "bytes": | |
| 485 return v, nil | |
| 486 | |
| 487 default: | |
| 488 return nil, fmt.Errorf("unknown type %q", p.Type) | |
| 489 } | |
| 490 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 1750143003:
Remove ephelper and other endpoints code. (Closed)
Base URL: https://github.com/luci/luci-go@master