feat: add externaldnscontext networkservice chain element (networkser…

…vicemesh#1295)

* add externaldnscontext pkg

Signed-off-by: denis-tingaikin <denis.tingajkin@xored.com>

* fix typos

Signed-off-by: denis-tingaikin <denis.tingajkin@xored.com>

pkg/networkservice/connectioncontext/externaldnscontext/server.go

@@ -0,0 +1,155 @@
+// Copyright (c) 2022 Cisco and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package externaldnscontext gets dnscontext from the remote side.
+package externaldnscontext
+
+import (
+	"context"
+	"errors"
+	"net"
+	"net/url"
+	"sync/atomic"
+	"time"
+
+	"github.com/golang/protobuf/ptypes/empty"
+	"github.com/networkservicemesh/api/pkg/api/dns"
+	"github.com/networkservicemesh/api/pkg/api/networkservice"
+
+	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
+
+	"google.golang.org/grpc"
+
+	"github.com/networkservicemesh/sdk/pkg/tools/grpcutils"
+	"github.com/networkservicemesh/sdk/pkg/tools/log"
+)
+
+type externaldnscontextServer struct {
+	serverLabels map[string]string
+	clientQueue  chan *dns.DNSRequest
+	configs      atomic.Value
+}
+
+// NewServer cretes new externaldnscontext networkservice server instance
+func NewServer(ctx context.Context, serverLabels map[string]string, remoteURL *url.URL, opts ...grpc.DialOption) networkservice.NetworkServiceServer {
+	var r = &externaldnscontextServer{
+		serverLabels: serverLabels,
+		clientQueue:  make(chan *dns.DNSRequest, 100),
+	}
+	var logger = log.FromContext(ctx).WithField("externaldnscontextServer", "managePrefixes go-routine")
+
+	r.configs.Store((*dns.Configs)(nil))
+
+	go func() {
+		defer close(r.clientQueue)
+		<-ctx.Done()
+	}()
+
+	go func() {
+		for ; ctx.Err() == nil; time.Sleep(time.Millisecond * 100) {
+			cc, err := grpc.DialContext(ctx, grpcutils.URLToTarget(remoteURL), opts...)
+			if err != nil {
+				logger.Errorf("cant dial: %v", err.Error())
+				continue
+			}
+			defer func() { _ = cc.Close() }()
+
+			c := dns.NewDNSClient(cc)
+			resp, err := c.FetchConfigs(ctx, new(empty.Empty))
+
+			if err != nil {
+				logger.Errorf("cant fetch configs: %v")
+			}
+
+			r.configs.Store(resp)
+
+			stream, err := c.ManageNames(ctx)
+			if err != nil {
+				logger.Errorf("cant open stream: %v", err.Error())
+				continue
+			}
+
+			for req := range r.clientQueue {
+				err = stream.Send(req)
+				if err != nil {
+					logger.Errorf("cant send msg: %v", err.Error())
+					break
+				}
+				_, err = stream.Recv()
+				if err != nil {
+					logger.Errorf("cant recv msg: %v", err.Error())
+					break
+				}
+			}
+			r.configs.Store((*dns.Configs)(nil))
+			_ = cc.Close()
+		}
+	}()
+
+	return r
+}
+
+func (e *externaldnscontextServer) Request(ctx context.Context, request *networkservice.NetworkServiceRequest) (*networkservice.Connection, error) {
+	var configs []*networkservice.DNSConfig
+
+	if v, ok := e.configs.Load().(*dns.Configs); ok && v != nil {
+		configs = v.Configs
+	} else {
+		return nil, errors.New("dns service is not ready yet")
+	}
+
+	if request.GetConnection() == nil {
+		request.Connection = new(networkservice.Connection)
+	}
+	if request.GetConnection().GetContext() == nil {
+		request.GetConnection().Context = new(networkservice.ConnectionContext)
+	}
+	if request.GetConnection().GetContext().GetDnsContext() == nil {
+		request.GetConnection().GetContext().DnsContext = new(networkservice.DNSContext)
+	}
+
+	e.enqueueDNSRequest(dns.Type_ASSIGN, e.serverLabels, request.GetConnection().GetContext().GetIpContext().GetDstIPNets())
+	e.enqueueDNSRequest(dns.Type_ASSIGN, request.GetConnection().GetLabels(), request.GetConnection().GetContext().GetIpContext().GetSrcIPNets())
+
+	request.GetConnection().GetContext().GetDnsContext().Configs = append(request.GetConnection().GetContext().GetDnsContext().Configs, configs...)
+
+	resp, err := next.Server(ctx).Request(ctx, request)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return resp, err
+}
+
+func (e *externaldnscontextServer) enqueueDNSRequest(t dns.Type, labels map[string]string, ipNets []*net.IPNet) {
+	var ips []string
+	for _, ipNet := range ipNets {
+		ips = append(ips, ipNet.IP.String())
+	}
+
+	select {
+	case e.clientQueue <- &dns.DNSRequest{Type: t, Ips: ips, Labels: labels}:
+	default:
+	}
+}
+
+func (e *externaldnscontextServer) Close(ctx context.Context, conn *networkservice.Connection) (*empty.Empty, error) {
+	e.enqueueDNSRequest(dns.Type_UNASSIGN, e.serverLabels, conn.GetContext().GetIpContext().GetDstIPNets())
+	e.enqueueDNSRequest(dns.Type_UNASSIGN, conn.GetLabels(), conn.GetContext().GetIpContext().GetSrcIPNets())
+
+	return next.Server(ctx).Close(ctx, conn)
+}

pkg/networkservice/connectioncontext/externaldnscontext/server_test.go

@@ -0,0 +1,237 @@
+// Copyright (c) 2022 Cisco and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package externaldnscontext_test
+
+import (
+	"context"
+	"net/url"
+	"sort"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/golang/protobuf/ptypes/empty"
+	"github.com/networkservicemesh/api/pkg/api/dns"
+	"github.com/networkservicemesh/api/pkg/api/networkservice"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/goleak"
+	"google.golang.org/grpc"
+
+	"github.com/networkservicemesh/sdk/pkg/networkservice/common/retry"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/connectioncontext/dnscontext"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/connectioncontext/externaldnscontext"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/core/adapters"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/core/chain"
+	"github.com/networkservicemesh/sdk/pkg/tools/grpcutils"
+)
+
+func newTestingDNSRegisterServce(ctx context.Context, t *testing.T) *testingDNSRegisterService {
+	var s = grpc.NewServer()
+
+	var r = new(testingDNSRegisterService)
+	dns.RegisterDNSServer(s, r)
+
+	var serverAddr url.URL
+
+	require.Len(t, grpcutils.ListenAndServe(ctx, &serverAddr, s), 0)
+
+	r.Addr = serverAddr
+	return r
+}
+
+type testingDNSRegisterService struct {
+	entries sync.Map
+	Addr    url.URL
+}
+
+func (e *testingDNSRegisterService) lenEntries() int {
+	var r int
+
+	e.entries.Range(func(key, value interface{}) bool {
+		r++
+		return true
+	})
+
+	return r
+}
+
+func (e *testingDNSRegisterService) FetchConfigs(ctx context.Context, _ *empty.Empty) (*dns.Configs, error) {
+	return &dns.Configs{Configs: []*networkservice.DNSConfig{{DnsServerIps: []string{"8.8.8.8"}}}}, nil
+}
+
+func (e *testingDNSRegisterService) ManageNames(s dns.DNS_ManageNamesServer) error {
+	for s.Context().Err() == nil {
+		r, err := s.Recv()
+		if err != nil {
+			return err
+		}
+		var values []string
+
+		for _, v := range r.Labels {
+			values = append(values, v)
+		}
+
+		sort.Strings(values)
+
+		var name = strings.Join(values, ".")
+
+		if r.Type == dns.Type_ASSIGN {
+			e.entries.Store(name, r.Ips[0])
+		} else {
+			e.entries.Delete(name)
+		}
+
+		err = s.Send(&dns.DNSResponse{
+			Names: []string{name},
+		})
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func Test_ExternalDNSContext_EmptyRequest(t *testing.T) {
+	t.Cleanup(func() { goleak.VerifyNone(t) })
+
+	var ctx, cancel = context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+
+	var s = newTestingDNSRegisterServce(ctx, t)
+
+	var c = retry.NewClient(
+		adapters.NewServerToClient(
+			externaldnscontext.NewServer(
+				ctx,
+				map[string]string{"app": "vl3", "podName": "nse1"},
+				&s.Addr, grpc.WithInsecure(),
+			),
+		),
+		retry.WithTryTimeout(time.Second/10),
+		retry.WithInterval(time.Millisecond*100),
+	)
+
+	_, err := c.Request(ctx, &networkservice.NetworkServiceRequest{})
+
+	require.NoError(t, err)
+}
+
+func Test_ExternalDNSContext_RequestRefreshClose(t *testing.T) {
+	t.Cleanup(func() { goleak.VerifyNone(t) })
+
+	var ctx, cancel = context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+
+	var s = newTestingDNSRegisterServce(ctx, t)
+
+	var c = retry.NewClient(
+		adapters.NewServerToClient(
+			externaldnscontext.NewServer(
+				ctx,
+				map[string]string{"app": "vl3", "podName": "nse1"},
+				&s.Addr, grpc.WithInsecure(),
+			),
+		),
+		retry.WithTryTimeout(time.Second/10),
+		retry.WithInterval(time.Millisecond*100),
+	)
+
+	req := &networkservice.NetworkServiceRequest{
+		Connection: &networkservice.Connection{
+			Id: t.Name(),
+			Context: &networkservice.ConnectionContext{
+				IpContext: &networkservice.IPContext{
+					SrcIpAddrs: []string{"1.1.1.1/32"},
+					DstIpAddrs: []string{"1.1.1.2/32"},
+				},
+			},
+		},
+	}
+
+	_, err := c.Request(ctx, req)
+
+	require.NoError(t, err)
+
+	require.Eventually(t, func() bool {
+		return s.lenEntries() == 2
+	}, time.Second/2, time.Second/10)
+
+	resp, err := c.Request(ctx, req)
+
+	require.NoError(t, err)
+
+	require.Eventually(t, func() bool {
+		return s.lenEntries() == 2
+	}, time.Second/2, time.Second/10)
+
+	_, err = c.Close(ctx, resp)
+	require.NoError(t, err)
+
+	require.Eventually(t, func() bool {
+		return s.lenEntries() == 0
+	}, time.Second/2, time.Second/10)
+}
+func Test_ExternalDNSContext_WorksCorrectly_WithDNSContext(t *testing.T) {
+	t.Cleanup(func() { goleak.VerifyNone(t) })
+
+	var ctx, cancel = context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+
+	var s = newTestingDNSRegisterServce(ctx, t)
+
+	var c = retry.NewClient(
+		adapters.NewServerToClient(
+			chain.NewNetworkServiceServer(
+				externaldnscontext.NewServer(
+					ctx,
+					map[string]string{"app": "vl3", "podName": "nse1"},
+					&s.Addr, grpc.WithInsecure(),
+				),
+				dnscontext.NewServer(&networkservice.DNSConfig{DnsServerIps: []string{"8.8.4.4"}}),
+			),
+		),
+		retry.WithTryTimeout(time.Second/10),
+		retry.WithInterval(time.Millisecond*100),
+	)
+
+	req := &networkservice.NetworkServiceRequest{
+		Connection: &networkservice.Connection{
+			Id: t.Name(),
+			Context: &networkservice.ConnectionContext{
+				IpContext: &networkservice.IPContext{
+					SrcIpAddrs: []string{"1.1.1.1/32"},
+					DstIpAddrs: []string{"1.1.1.2/32"},
+				},
+			},
+		},
+	}
+
+	resp, err := c.Request(ctx, req)
+
+	require.NoError(t, err)
+
+	var ips []string
+
+	for _, cfg := range resp.GetContext().GetDnsContext().GetConfigs() {
+		ips = append(ips, cfg.DnsServerIps...)
+	}
+
+	require.Equal(t, []string{"8.8.8.8", "8.8.4.4"}, ips)
+}