server: allow cors http request (#7939)

Author: Kingwl

config/config.go

@@ -47,6 +47,7 @@ type Config struct {
 	Host             string          `toml:"host" json:"host"`
 	AdvertiseAddress string          `toml:"advertise-address" json:"advertise-address"`
 	Port             uint            `toml:"port" json:"port"`
+	Cors             string          `toml:"cors" json:"cors"`
 	Store            string          `toml:"store" json:"store"`
 	Path             string          `toml:"path" json:"path"`
 	Socket           string          `toml:"socket" json:"socket"`
@@ -252,6 +253,7 @@ var defaultConf = Config{
 	Host:             "0.0.0.0",
 	AdvertiseAddress: "",
 	Port:             4000,
+	Cors:             "",
 	Store:            "mocktikv",
 	Path:             "/tmp/tidb",
 	RunDDL:           true,

server/http_status.go

@@ -117,7 +117,7 @@ func (s *Server) startHTTPServer() {
 	})
 
 	log.Infof("Listening on %v for status and metrics report.", addr)
-	s.statusServer = &http.Server{Addr: addr, Handler: serverMux}
+	s.statusServer = &http.Server{Addr: addr, Handler: CorsHandler{handler: serverMux, cfg: s.cfg}}
 
 	if len(s.cfg.Security.ClusterSSLCA) != 0 {
 		err = s.statusServer.ListenAndServeTLS(s.cfg.Security.ClusterSSLCert, s.cfg.Security.ClusterSSLKey)

server/util.go

@@ -39,9 +39,11 @@ import (
 	"encoding/binary"
 	"io"
 	"math"
+	"net/http"
 	"strconv"
 	"time"
 
+	"github.com/pingcap/tidb/config"
 	"github.com/pingcap/tidb/mysql"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
@@ -354,3 +356,17 @@ func appendFormatFloat(in []byte, fVal float64, prec, bitSize int) []byte {
 	}
 	return out
 }
+
+// CorsHandler adds Cors Header if `cors` config is set.
+type CorsHandler struct {
+	handler http.Handler
+	cfg     *config.Config
+}
+
+func (h CorsHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	if h.cfg.Cors != "" {
+		w.Header().Set("Access-Control-Allow-Origin", h.cfg.Cors)
+		w.Header().Set("Access-Control-Allow-Methods", "GET")
+	}
+	h.handler.ServeHTTP(w, req)
+}

tidb-server/main.go

@@ -64,6 +64,7 @@ const (
 	nmHost             = "host"
 	nmAdvertiseAddress = "advertise-address"
 	nmPort             = "P"
+	nmCors             = "cors"
 	nmSocket           = "socket"
 	nmBinlogSocket     = "binlog-socket"
 	nmRunDDL           = "run-ddl"
@@ -91,6 +92,7 @@ var (
 	host             = flag.String(nmHost, "0.0.0.0", "tidb server host")
 	advertiseAddress = flag.String(nmAdvertiseAddress, "", "tidb server advertise IP")
 	port             = flag.String(nmPort, "4000", "tidb server port")
+	cors             = flag.String(nmCors, "", "tidb server allow cors origin")
 	socket           = flag.String(nmSocket, "", "The socket file to use for connection.")
 	binlogSocket     = flag.String(nmBinlogSocket, "", "socket file to write binlog")
 	runDDL           = flagBoolean(nmRunDDL, true, "run ddl worker on this tidb-server")
@@ -278,6 +280,10 @@ func overrideConfig() {
 		terror.MustNil(err)
 		cfg.Port = uint(p)
 	}
+	if actualFlags[nmCors] {
+		fmt.Println(cors)
+		cfg.Cors = *cors
+	}
 	if actualFlags[nmStore] {
 		cfg.Store = *store
 	}