Merge pull request ipfs/kubo#1529 from ipfs/cors-fix

Fix CORS Support

This commit was moved from ipfs/kubo@9e4d6e1

gateway/core/corehttp/commands.go

@@ -3,22 +3,73 @@ package corehttp
 import (
 	"net/http"
 	"os"
+	"strings"
+
+	cors "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/rs/cors"
 
 	commands "github.com/ipfs/go-ipfs/commands"
 	cmdsHttp "github.com/ipfs/go-ipfs/commands/http"
 	core "github.com/ipfs/go-ipfs/core"
 	corecommands "github.com/ipfs/go-ipfs/core/commands"
+	config "github.com/ipfs/go-ipfs/repo/config"
 )
 
-const (
-	// TODO rename
-	originEnvKey = "API_ORIGIN"
-)
+const originEnvKey = "API_ORIGIN"
+const originEnvKeyDeprecate = `You are using the ` + originEnvKey + `ENV Variable.
+This functionality is deprecated, and will be removed in future versions.
+Instead, try either adding headers to the config, or passing them via
+cli arguments:
+
+	ipfs config API.HTTPHeaders 'Access-Control-Allow-Origin' '*'
+	ipfs daemon
+
+or
+
+	ipfs daemon --api-http-header 'Access-Control-Allow-Origin: *'
+`
+
+func addCORSFromEnv(c *cmdsHttp.ServerConfig) {
+	origin := os.Getenv(originEnvKey)
+	if origin != "" {
+		log.Warning(originEnvKeyDeprecate)
+		if c.CORSOpts == nil {
+			c.CORSOpts.AllowedOrigins = []string{origin}
+		}
+		c.CORSOpts.AllowedOrigins = append(c.CORSOpts.AllowedOrigins, origin)
+	}
+}
+
+func addHeadersFromConfig(c *cmdsHttp.ServerConfig, nc *config.Config) {
+	log.Info("Using API.HTTPHeaders:", nc.API.HTTPHeaders)
+
+	if acao := nc.API.HTTPHeaders[cmdsHttp.ACAOrigin]; acao != nil {
+		c.CORSOpts.AllowedOrigins = acao
+	}
+	if acam := nc.API.HTTPHeaders[cmdsHttp.ACAMethods]; acam != nil {
+		c.CORSOpts.AllowedMethods = acam
+	}
+	if acac := nc.API.HTTPHeaders[cmdsHttp.ACACredentials]; acac != nil {
+		for _, v := range acac {
+			c.CORSOpts.AllowCredentials = (strings.ToLower(v) == "true")
+		}
+	}
+
+	c.Headers = nc.API.HTTPHeaders
+}
 
 func CommandsOption(cctx commands.Context) ServeOption {
 	return func(n *core.IpfsNode, mux *http.ServeMux) (*http.ServeMux, error) {
-		origin := os.Getenv(originEnvKey)
-		cmdHandler := cmdsHttp.NewHandler(cctx, corecommands.Root, origin)
+
+		cfg := &cmdsHttp.ServerConfig{
+			CORSOpts: &cors.Options{
+				AllowedMethods: []string{"GET", "POST", "PUT"},
+			},
+		}
+
+		addHeadersFromConfig(cfg, n.Repo.Config())
+		addCORSFromEnv(cfg)
+
+		cmdHandler := cmdsHttp.NewHandler(cctx, corecommands.Root, cfg)
 		mux.Handle(cmdsHttp.ApiPath+"/", cmdHandler)
 		return mux, nil
 	}

gateway/core/corehttp/gateway.go

@@ -15,6 +15,7 @@ type Gateway struct {
 }
 
 type GatewayConfig struct {
+	Headers   map[string][]string
 	BlockList *BlockList
 	Writable  bool
 }
@@ -27,6 +28,9 @@ func NewGateway(conf GatewayConfig) *Gateway {
 
 func (g *Gateway) ServeOption() ServeOption {
 	return func(n *core.IpfsNode, mux *http.ServeMux) (*http.ServeMux, error) {
+		// pass user's HTTP headers
+		g.Config.Headers = n.Repo.Config().Gateway.HTTPHeaders
+
 		gateway, err := newGatewayHandler(n, g.Config)
 		if err != nil {
 			return nil, err

gateway/core/corehttp/gateway_handler.go

@@ -106,6 +106,7 @@ func (i *gatewayHandler) getOrHeadHandler(w http.ResponseWriter, r *http.Request
 		return
 	}
 
+	i.addUserHeaders(w) // ok, _now_ write user's headers.
 	w.Header().Set("X-IPFS-Path", urlPath)
 
 	// Suborigin header, sandboxes apps from each other in the browser (even
@@ -229,6 +230,7 @@ func (i *gatewayHandler) postHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	i.addUserHeaders(w) // ok, _now_ write user's headers.
 	w.Header().Set("IPFS-Hash", k.String())
 	http.Redirect(w, r, ipfsPathPrefix+k.String(), http.StatusCreated)
 }
@@ -242,6 +244,7 @@ func (i *gatewayHandler) putEmptyDirHandler(w http.ResponseWriter, r *http.Reque
 		return
 	}
 
+	i.addUserHeaders(w) // ok, _now_ write user's headers.
 	w.Header().Set("IPFS-Hash", key.String())
 	http.Redirect(w, r, ipfsPathPrefix+key.String()+"/", http.StatusCreated)
 }
@@ -340,6 +343,7 @@ func (i *gatewayHandler) putHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	i.addUserHeaders(w) // ok, _now_ write user's headers.
 	w.Header().Set("IPFS-Hash", key.String())
 	http.Redirect(w, r, ipfsPathPrefix+key.String()+"/"+strings.Join(components, "/"), http.StatusCreated)
 }
@@ -411,10 +415,17 @@ func (i *gatewayHandler) deleteHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	i.addUserHeaders(w) // ok, _now_ write user's headers.
 	w.Header().Set("IPFS-Hash", key.String())
 	http.Redirect(w, r, ipfsPathPrefix+key.String()+"/"+strings.Join(components[:len(components)-1], "/"), http.StatusCreated)
 }
 
+func (i *gatewayHandler) addUserHeaders(w http.ResponseWriter) {
+	for k, v := range i.config.Headers {
+		w.Header()[k] = v
+	}
+}
+
 func webError(w http.ResponseWriter, message string, err error, defaultCode int) {
 	if _, ok := err.(path.ErrNoLink); ok {
 		webErrorWithCode(w, message, err, http.StatusNotFound)