cri/pkg: use our own interceptor grpc chain function

The grpc middleware uses difference protobuf version from
containerd@v1.2. In order to align with containerd, we should use our
own interceptor grpc chain function.

Signed-off-by: Wei Fu <fuweid89@gmail.com>

cri/v1alpha2/service.go

@@ -10,7 +10,6 @@ import (
 	"github.com/alibaba/pouch/pkg/grpc/interceptor"
 	"github.com/alibaba/pouch/pkg/netutils"
 
-	"github.com/grpc-ecosystem/go-grpc-middleware"
 	"github.com/sirupsen/logrus"
 	"google.golang.org/grpc"
 )
@@ -29,7 +28,7 @@ func NewService(cfg *config.Config, criMgr CriMgr) (*Service, error) {
 		config: cfg,
 		server: grpc.NewServer(
 			grpc.StreamInterceptor(metrics.GRPCMetrics.StreamServerInterceptor()),
-			grpc_middleware.WithUnaryServerChain(
+			interceptor.WithUnaryServerChain(
 				metrics.GRPCMetrics.UnaryServerInterceptor(),
 				interceptor.PayloadUnaryServerInterceptor(logEntry, criLogLevelDecider),
 			),

pkg/grpc/interceptor/chain.go

@@ -0,0 +1,31 @@
+package interceptor
+
+import (
+	"context"
+
+	"google.golang.org/grpc"
+)
+
+// WithUnaryServerChain creates a single interceptor out of a chain of many interceptors.
+func WithUnaryServerChain(interceptors ...grpc.UnaryServerInterceptor) grpc.ServerOption {
+	return grpc.UnaryInterceptor(chainUnaryServer(interceptors...))
+}
+
+// chainUnaryServer creates a single interceptor out of a chain of many interceptors.
+//
+// Execution is done in left-to-right order.
+func chainUnaryServer(interceptors ...grpc.UnaryServerInterceptor) grpc.UnaryServerInterceptor {
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		buildChain := func(current grpc.UnaryServerInterceptor, next grpc.UnaryHandler) grpc.UnaryHandler {
+			return func(currentCtx context.Context, currentReq interface{}) (interface{}, error) {
+				return current(currentCtx, currentReq, info, next)
+			}
+		}
+
+		chain := handler
+		for i := len(interceptors) - 1; i >= 0; i-- {
+			chain = buildChain(interceptors[i], chain)
+		}
+		return chain(ctx, req)
+	}
+}

pkg/grpc/interceptor/chain_test.go

@@ -0,0 +1,50 @@
+package interceptor
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"google.golang.org/grpc"
+)
+
+func TestChainUnaryServer(t *testing.T) {
+	type key int
+
+	var (
+		serviceName  = "Foo.UnaryMethod"
+		theUnaryInfo = &grpc.UnaryServerInfo{FullMethod: serviceName}
+
+		keyFirst    key = 1
+		keySecond   key = 2
+		valueFirst      = "I'm first"
+		valueSecond     = "I'm second"
+
+		input  = "input"
+		result = "result"
+	)
+
+	first := func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		assert.Equal(t, ctx.Value(keyFirst), nil, "there should be no first value")
+		assert.Equal(t, info, theUnaryInfo)
+		return handler(context.WithValue(ctx, keyFirst, valueFirst), req)
+	}
+
+	second := func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		assert.Equal(t, ctx.Value(keyFirst), valueFirst, "there should be first value")
+		assert.Equal(t, ctx.Value(keySecond), nil, "there should be no second value")
+		assert.Equal(t, info, theUnaryInfo)
+		return handler(context.WithValue(ctx, keySecond, valueSecond), req)
+	}
+
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		assert.Equal(t, req, input, "check the input")
+		assert.Equal(t, ctx.Value(keyFirst), valueFirst, "there should be first value")
+		assert.Equal(t, ctx.Value(keySecond), valueSecond, "there should be second value")
+		return result, nil
+	}
+
+	output, err := chainUnaryServer(first, second)(context.TODO(), input, theUnaryInfo, handler)
+	assert.Equal(t, err, nil)
+	assert.Equal(t, output, result)
+}