Add skeleton of the proxy

mtglib/stream_context.go

@@ -0,0 +1,63 @@
+package mtglib
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/base64"
+	"net"
+	"time"
+)
+
+type streamContext struct {
+	ctx        context.Context
+	ctxCancel  context.CancelFunc
+	clientConn net.Conn
+	connID     string
+	logger     Logger
+}
+
+func (s *streamContext) Deadline() (time.Time, bool) {
+	return s.ctx.Deadline()
+}
+
+func (s *streamContext) Done() <-chan struct{} {
+	return s.ctx.Done()
+}
+
+func (s *streamContext) Err() error {
+	return s.ctx.Err()
+}
+
+func (s *streamContext) Value(key interface{}) interface{} {
+	return s.ctx.Value(key)
+}
+
+func (s *streamContext) Close() {
+	s.ctxCancel()
+	s.clientConn.Close()
+}
+
+func (s *streamContext) ClientIP() net.IP {
+	return s.clientConn.RemoteAddr().(*net.TCPAddr).IP
+}
+
+func newStreamContext(ctx context.Context, logger Logger, clientConn net.Conn) *streamContext {
+	connIDBytes := make([]byte, 16)
+
+	if _, err := rand.Read(connIDBytes); err != nil {
+		panic(err)
+	}
+
+	ctx, cancel := context.WithCancel(ctx)
+	streamCtx := &streamContext{
+		ctx:        ctx,
+		ctxCancel:  cancel,
+		clientConn: clientConn,
+		connID:     base64.RawURLEncoding.EncodeToString(connIDBytes),
+	}
+	streamCtx.logger = logger.
+		BindStr("stream-id", streamCtx.connID).
+		BindStr("client-ip", streamCtx.ClientIP().String())
+
+	return streamCtx
+}