etcd/http/cors.go
Brian Waldon 0abd860f7e refactor(server): drop Serve code; rename cors object
* server/cors.go renamed to http/cors.go
* all CORS code removed from Server and PeerServer
* Server and PeerServer fulfill http.Handler, now passed to http.Serve
* non-HTTP code in PeerServer.Serve moved to PeerServer.Start
2014-01-22 11:17:57 -08:00

76 lines
1.9 KiB
Go

/*
Copyright 2013 CoreOS Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package http
import (
"fmt"
"net/http"
"net/url"
)
type CORSInfo map[string]bool
func NewCORSInfo(origins []string) (*CORSInfo, error) {
// Construct a lookup of all origins.
m := make(map[string]bool)
for _, v := range origins {
if v != "*" {
if _, err := url.Parse(v); err != nil {
return nil, fmt.Errorf("Invalid CORS origin: %s", err)
}
}
m[v] = true
}
info := CORSInfo(m)
return &info, nil
}
// OriginAllowed determines whether the server will allow a given CORS origin.
func (c CORSInfo) OriginAllowed(origin string) bool {
return c["*"] || c[origin]
}
type CORSHandler struct {
Handler http.Handler
Info *CORSInfo
}
// addHeader adds the correct cors headers given an origin
func (h *CORSHandler) addHeader(w http.ResponseWriter, origin string) {
w.Header().Add("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
w.Header().Add("Access-Control-Allow-Origin", origin)
}
// ServeHTTP adds the correct CORS headers based on the origin and returns immediatly
// with a 200 OK if the method is OPTIONS.
func (h *CORSHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
// Write CORS header.
if h.Info.OriginAllowed("*") {
h.addHeader(w, "*")
} else if origin := req.Header.Get("Origin"); h.Info.OriginAllowed(origin) {
h.addHeader(w, origin)
}
if req.Method == "OPTIONS" {
w.WriteHeader(http.StatusOK)
return
}
h.Handler.ServeHTTP(w, req)
}