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package main
import (
"context"
"encoding/json"
"log"
"net/http"
"os"
"os/signal"
"syscall"
"time"
_ "net/http/pprof"
"github.com/centrifugal/centrifuge/_examples/jwt_token/jwt"
"github.com/centrifugal/centrifuge"
)
type clientMessage struct {
Timestamp int64 `json:"timestamp"`
Input string `json:"input"`
}
func handleLog(e centrifuge.LogEntry) {
log.Printf("%s: %v", e.Message, e.Fields)
}
func waitExitSignal(n *centrifuge.Node) {
sigCh := make(chan os.Signal, 1)
done := make(chan bool, 1)
signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
go func() {
<-sigCh
_ = n.Shutdown(context.Background())
done <- true
}()
<-done
}
// Check whether channel is allowed for subscribing. In real case permission
// most probably will be more complex than in this example.
func channelSubscribeAllowed(channel string) bool {
return channel == "chat"
}
func main() {
cfg := centrifuge.DefaultConfig
cfg.LogLevel = centrifuge.LogLevelInfo
cfg.LogHandler = handleLog
node, _ := centrifuge.New(cfg)
broker, _ := centrifuge.NewMemoryBroker(node, centrifuge.MemoryBrokerConfig{
HistoryMetaTTL: 120 * time.Second,
})
node.SetBroker(broker)
tokenVerifier := jwt.NewTokenVerifier(jwt.TokenVerifierConfig{
HMACSecretKey: "secret",
})
node.OnConnecting(func(ctx context.Context, e centrifuge.ConnectEvent) (centrifuge.ConnectReply, error) {
log.Printf("client connecting with token: %s", e.Token)
token, err := tokenVerifier.VerifyConnectToken(e.Token)
if err != nil {
if err == jwt.ErrTokenExpired {
return centrifuge.ConnectReply{}, centrifuge.ErrorTokenExpired
}
return centrifuge.ConnectReply{}, centrifuge.DisconnectInvalidToken
}
subs := make(map[string]centrifuge.SubscribeOptions, len(token.Channels))
for _, ch := range token.Channels {
subs[ch] = centrifuge.SubscribeOptions{}
}
return centrifuge.ConnectReply{
Credentials: ¢rifuge.Credentials{
UserID: token.UserID,
ExpireAt: token.ExpireAt,
},
Subscriptions: subs,
}, nil
})
node.OnConnect(func(client *centrifuge.Client) {
transport := client.Transport()
log.Printf("user %s connected via %s with protocol: %s", client.UserID(), transport.Name(), transport.Protocol())
client.OnRefresh(func(e centrifuge.RefreshEvent, cb centrifuge.RefreshCallback) {
log.Printf("user %s connection is going to expire, refreshing", client.UserID())
cb(centrifuge.RefreshReply{ExpireAt: time.Now().Unix() + 60}, nil)
})
client.OnSubscribe(func(e centrifuge.SubscribeEvent, cb centrifuge.SubscribeCallback) {
log.Printf("user %s subscribes on %s", client.UserID(), e.Channel)
if !channelSubscribeAllowed(e.Channel) {
cb(centrifuge.SubscribeReply{}, centrifuge.ErrorPermissionDenied)
return
}
cb(centrifuge.SubscribeReply{}, nil)
})
client.OnPublish(func(e centrifuge.PublishEvent, cb centrifuge.PublishCallback) {
log.Printf("user %s publishes into channel %s: %s", client.UserID(), e.Channel, string(e.Data))
if !client.IsSubscribed(e.Channel) {
cb(centrifuge.PublishReply{}, centrifuge.ErrorPermissionDenied)
return
}
var msg clientMessage
err := json.Unmarshal(e.Data, &msg)
if err != nil {
cb(centrifuge.PublishReply{}, centrifuge.ErrorBadRequest)
return
}
cb(centrifuge.PublishReply{}, nil)
})
client.OnDisconnect(func(e centrifuge.DisconnectEvent) {
log.Printf("user %s disconnected, disconnect: %s", client.UserID(), e.Disconnect)
})
})
if err := node.Run(); err != nil {
log.Fatal(err)
}
websocketHandler := centrifuge.NewWebsocketHandler(node, centrifuge.WebsocketConfig{
ReadBufferSize: 1024,
UseWriteBufferPool: true,
})
http.Handle("/connection/websocket", websocketHandler)
http.Handle("/token", http.HandlerFunc(func(w http.ResponseWriter, request *http.Request) {
w.Header().Set("Content-Type", "application/json")
token, err := jwt.BuildUserToken("secret", "42", time.Now().Unix()+10)
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
return
}
_, _ = w.Write([]byte(`{"token": "` + token + `"}`))
}))
http.Handle("/", http.FileServer(http.Dir("./")))
go func() {
if err := http.ListenAndServe(":8000", nil); err != nil {
log.Fatal(err)
}
}()
waitExitSignal(node)
log.Println("bye!")
}
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