add observer

hop/plugin/grpc.go

@@ -0,0 +1,101 @@
+package hop
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+
+	"github.com/go-gost/core/chain"
+	"github.com/go-gost/core/hop"
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/plugin/hop/proto"
+	"github.com/go-gost/x/config"
+	node_parser "github.com/go-gost/x/config/parsing/node"
+	ctxvalue "github.com/go-gost/x/internal/ctx"
+	"github.com/go-gost/x/internal/plugin"
+	"google.golang.org/grpc"
+)
+
+type grpcPlugin struct {
+	name   string
+	conn   grpc.ClientConnInterface
+	client proto.HopClient
+	log    logger.Logger
+}
+
+// NewGRPCPlugin creates a Hop plugin based on gRPC.
+func NewGRPCPlugin(name string, addr string, opts ...plugin.Option) hop.Hop {
+	var options plugin.Options
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	log := logger.Default().WithFields(map[string]any{
+		"kind": "hop",
+		"hop":  name,
+	})
+	conn, err := plugin.NewGRPCConn(addr, &options)
+	if err != nil {
+		log.Error(err)
+	}
+
+	p := &grpcPlugin{
+		name: name,
+		conn: conn,
+		log:  log,
+	}
+	if conn != nil {
+		p.client = proto.NewHopClient(conn)
+	}
+	return p
+}
+
+func (p *grpcPlugin) Select(ctx context.Context, opts ...hop.SelectOption) *chain.Node {
+	if p.client == nil {
+		return nil
+	}
+
+	var options hop.SelectOptions
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	r, err := p.client.Select(ctx,
+		&proto.SelectRequest{
+			Network: options.Network,
+			Addr:    options.Addr,
+			Host:    options.Host,
+			Path:    options.Path,
+			Client:  string(ctxvalue.ClientIDFromContext(ctx)),
+			Src:     string(ctxvalue.ClientAddrFromContext(ctx)),
+		})
+	if err != nil {
+		p.log.Error(err)
+		return nil
+	}
+
+	if r.Node == nil {
+		return nil
+	}
+
+	var cfg config.NodeConfig
+	if err := json.NewDecoder(bytes.NewReader(r.Node)).Decode(&cfg); err != nil {
+		p.log.Error(err)
+		return nil
+	}
+
+	node, err := node_parser.ParseNode(p.name, &cfg, logger.Default())
+	if err != nil {
+		p.log.Error(err)
+		return nil
+	}
+	return node
+}
+
+func (p *grpcPlugin) Close() error {
+	if closer, ok := p.conn.(io.Closer); ok {
+		return closer.Close()
+	}
+	return nil
+}