feat: adaptation for gRPC

Author: saicaca

pkg/adapters/grpc/traffic.go

@@ -0,0 +1,75 @@
+package grpc
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"github.com/alibaba/sentinel-golang/core/route"
+	"github.com/alibaba/sentinel-golang/core/route/base"
+	"google.golang.org/grpc/metadata"
+	"net"
+	"strings"
+)
+
+type DialerOption func(*dialerOptions)
+type dialerOptions struct {
+	cm *route.ClusterManager
+	md metadata.MD
+}
+
+func NewDialer(opts ...DialerOption) func(context.Context, string) (net.Conn, error) {
+	options := evaluateDialerOptions(opts)
+	return func(ctx context.Context, addr string) (net.Conn, error) {
+		cm := options.cm
+		parts := strings.Split(addr, "/")
+		if len(parts) != 2 {
+			return nil, errors.New("invalid address format")
+		}
+		tc := &base.TrafficContext{
+			ServiceName: parts[0],
+			MethodName:  parts[1],
+			Headers:     make(map[string]string),
+		}
+
+		for key, vals := range options.md {
+			if len(vals) == 0 {
+				continue
+			}
+			tc.Headers[key] = vals[len(vals)-1]
+		}
+
+		instance, err := cm.GetOne(tc)
+
+		for k, v := range tc.Baggage {
+			options.md[k] = []string{v}
+		}
+
+		if err != nil {
+			return nil, err
+		}
+		if instance == nil {
+			return nil, errors.New("no matched provider")
+		}
+		return net.Dial("tcp", fmt.Sprintf("%s:%v", instance.Host, instance.Port))
+	}
+}
+
+func WithClusterManager(cm *route.ClusterManager) DialerOption {
+	return func(d *dialerOptions) {
+		d.cm = cm
+	}
+}
+
+func WithMetadata(md metadata.MD) DialerOption {
+	return func(d *dialerOptions) {
+		d.md = md
+	}
+}
+
+func evaluateDialerOptions(opts []DialerOption) *dialerOptions {
+	ret := &dialerOptions{}
+	for _, opt := range opts {
+		opt(ret)
+	}
+	return ret
+}