add observer

admission/plugin/grpc.go

@@ -0,0 +1,67 @@
+package admission
+
+import (
+	"context"
+	"io"
+
+	"github.com/go-gost/core/admission"
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/plugin/admission/proto"
+	"github.com/go-gost/x/internal/plugin"
+	"google.golang.org/grpc"
+)
+
+type grpcPlugin struct {
+	conn   grpc.ClientConnInterface
+	client proto.AdmissionClient
+	log    logger.Logger
+}
+
+// NewGRPCPlugin creates an Admission plugin based on gRPC.
+func NewGRPCPlugin(name string, addr string, opts ...plugin.Option) admission.Admission {
+	var options plugin.Options
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	log := logger.Default().WithFields(map[string]any{
+		"kind":      "admission",
+		"admission": name,
+	})
+	conn, err := plugin.NewGRPCConn(addr, &options)
+	if err != nil {
+		log.Error(err)
+	}
+
+	p := &grpcPlugin{
+		conn: conn,
+		log:  log,
+	}
+	if conn != nil {
+		p.client = proto.NewAdmissionClient(conn)
+	}
+	return p
+}
+
+func (p *grpcPlugin) Admit(ctx context.Context, addr string, opts ...admission.Option) bool {
+	if p.client == nil {
+		return false
+	}
+
+	r, err := p.client.Admit(ctx,
+		&proto.AdmissionRequest{
+			Addr: addr,
+		})
+	if err != nil {
+		p.log.Error(err)
+		return false
+	}
+	return r.Ok
+}
+
+func (p *grpcPlugin) Close() error {
+	if closer, ok := p.conn.(io.Closer); ok {
+		return closer.Close()
+	}
+	return nil
+}