Working websocket connection

Author: Kelwing

Dockerfile

@@ -1,3 +1,6 @@
+FROM alpine:latest as certs
+RUN apk --update add ca-certificates
+
 FROM golang:latest as builder
 WORKDIR /go/src/gitea.auttaja.io/kubecord/ws
 RUN go get github.com/gorilla/websocket \
@@ -9,5 +12,6 @@ COPY . .
 RUN CGO_ENABLED=0 go build -installsuffix 'static' -o /app .
 
 FROM scratch as final
+COPY --from=certs /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
 COPY --from=builder /app /app
 ENTRYPOINT ["/app"]

constants.go

@@ -18,3 +18,5 @@ const (
 )
 
 const FailedHeartbeatAcks = 5 * time.Millisecond
+
+const APIBase = "https://discordapp.com/api/v6"

http.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"encoding/json"
+	"github.com/labstack/gommon/log"
+	"io/ioutil"
+	"net/http"
+	"strings"
+	"time"
+)
+
+func (s *Shard) GatewayBot() (st *GatewayBotResponse, err error) {
+
+	client := &http.Client{Timeout: time.Second * 10}
+
+	req, err := http.NewRequest("GET", APIBase+"/gateway/bot", nil)
+
+	req.Header.Set("Authorization", "Bot "+s.Token)
+
+	response, err := client.Do(req)
+	if err != nil {
+		log.Fatal("Error getting Gateway data: ", err)
+		return
+	}
+
+	defer func() {
+		err := response.Body.Close()
+		if err != nil {
+			return
+		}
+	}()
+
+	body, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		log.Fatal("error reading gateway response body ", err)
+	}
+
+	err = json.Unmarshal(body, &st)
+	if err != nil {
+		return
+	}
+
+	// Ensure the gateway always has a trailing slash.
+	// MacOS will fail to connect if we add query params without a trailing slash on the base domain.
+	if !strings.HasSuffix(st.URL, "/") {
+		st.URL += "/"
+	}
+
+	return
+}

main.go

@@ -1,7 +1,38 @@
 package main
 
-import "fmt"
+import (
+	"fmt"
+	"github.com/labstack/gommon/log"
+	"os"
+	"os/signal"
+	"syscall"
+)
 
 func main() {
-	fmt.Println("Testing")
+	log.SetLevel(log.INFO)
+	token := os.Getenv("TOKEN")
+	client := Shard{Token: token}
+	GatewayData, err := client.GatewayBot()
+	if err != nil {
+		log.Fatal("Unable to get GatewayBot data")
+	}
+	shards := make([]Shard, GatewayData.Shards)
+	initSequence := int64(0)
+	for sid, shard := range shards {
+		shard.Sequence = &initSequence
+		shard.SessionID = ""
+		shard.Token = token
+		shard.ShardCount = GatewayData.Shards
+		shard.ShardId = sid
+		_ = shard.Open(GatewayData.URL)
+	}
+
+	// Wait here until CTRL-C or other term signal is received.
+	fmt.Println("Bot is now running.  Press CTRL-C to exit.")
+	sc := make(chan os.Signal, 1)
+	signal.Notify(sc, syscall.SIGINT, syscall.SIGTERM, os.Interrupt, os.Kill)
+	<-sc
+
+	// Cleanly close down the Discord session.
+	_ = client.Close()
 }

structs.go

@@ -89,6 +89,11 @@ type ResumePayload struct {
 	Data ResumeData `json:"d"`
 }
 
+type GatewayBotResponse struct {
+	URL    string `json:"url"`
+	Shards int    `json:"shards"`
+}
+
 /* Gateway objects */
 
 type User struct {

ws.go

@@ -47,15 +47,15 @@ func (s *Shard) Open(gateway string) error {
 		return ErrWSAlreadyOpen
 	}
 	s.Gateway = gateway
-	gateway = gateway + "?v=6&encoding=json&compress=zlib-stream"
+	gateway = gateway + "?v=6&encoding=json"
 
-	log.Info("Shard %d connecting to gateway", s.ShardId)
+	log.Infof("Shard %d connecting to gateway", s.ShardId)
 	header := http.Header{}
 	header.Add("accept-encoding", "zlib")
 
 	s.Conn, _, err = websocket.DefaultDialer.Dial(gateway, header)
 	if err != nil {
-		log.Warn("error connecting to gateway on shard %d", err)
+		log.Warnf("error connecting to gateway on shard %d", err)
 		s.Conn = nil
 		return err
 	}
@@ -176,6 +176,7 @@ func (s *Shard) onPayload(wsConn *websocket.Conn, listening <-chan interface{})
 			s.RUnlock()
 
 			if sameConnection {
+				log.Warnf("error reading from gateway on shard %d: %s", s.ShardId, err)
 				err := s.Close()
 				if err != nil {
 					log.Warn("error closing connection, %s", err)
@@ -203,30 +204,34 @@ func (s *Shard) Dispatch(messageType int, message []byte) (*GatewayPayload, erro
 	var err error
 	var e *GatewayPayload
 	buffer = bytes.NewBuffer(message)
-
+	log.Debugf("Got event on shard %d", s.ShardId)
 	if messageType == websocket.BinaryMessage {
 		decompressor, zerr := zlib.NewReader(buffer)
 		if zerr != nil {
-			log.Error("error decompressing message: %s", zerr)
+			log.Errorf("error decompressing message: %s", zerr)
+			return nil, zerr
 		}
 
 		defer func() {
 			zerr := decompressor.Close()
 			if zerr != nil {
-				log.Warn("error closing zlib: %s", zerr)
+				log.Warnf("error closing zlib: %s", zerr)
+				return
 			}
 		}()
 
 		buffer = decompressor
 	}
 
+	log.Debugf("Decompressed message on shard %d", s.ShardId)
+
 	decoder := json.NewDecoder(buffer)
 	if err = decoder.Decode(&e); err != nil {
 		log.Error("error decoding message: %s", err)
 		return e, err
 	}
 
-	log.Debug("Op: %d, Seq: %d, Type: %s, Data: %s\n\n", e.Op, e.Sequence, e.Event, string(e.Data))
+	log.Debugf("Op: %d, Seq: %d, Type: %s, Data: %s\n\n", e.Op, e.Sequence, e.Event, string(e.Data))
 
 	switch e.Op {
 	case OP_HEARTBEAT:
@@ -246,7 +251,7 @@ func (s *Shard) Dispatch(messageType int, message []byte) (*GatewayPayload, erro
 	case OP_INVALID_SESSION:
 		err = s.Identify()
 		if err != nil {
-			log.Error("error identifying with gateway: %s", err)
+			log.Errorf("error identifying with gateway: %s", err)
 			return e, err
 		}
 		return e, nil
@@ -256,14 +261,15 @@ func (s *Shard) Dispatch(messageType int, message []byte) (*GatewayPayload, erro
 		s.Lock()
 		s.LastHeartbeatAck = time.Now().UTC()
 		s.Unlock()
-		log.Debug("got heartbeat ACK")
+		log.Debugf("got heartbeat ACK")
 		return e, nil
 	case OP_DISPATCH:
 		// Dispatch the message
 		atomic.StoreInt64(s.Sequence, e.Sequence)
+		log.Debugf("Got event %s on shard %d", e.Event, s.ShardId)
 		return e, nil
 	default:
-		log.Warn("Unknown Op: %d", e.Op)
+		log.Warnf("Unknown Op: %d", e.Op)
 		return e, nil
 	}
 }