server_test.go

/*
Copyright 2019 The Kubernetes Authors.

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 server

import (
	"context"
	"fmt"
	"io"
	"reflect"
	"testing"
	"time"

	"github.com/golang/mock/gomock"
	"github.com/google/uuid"
	"google.golang.org/grpc/metadata"

	authv1 "k8s.io/api/authentication/v1"
	"k8s.io/apimachinery/pkg/runtime"
	k8sfake "k8s.io/client-go/kubernetes/fake"
	fakeauthenticationv1 "k8s.io/client-go/kubernetes/typed/authentication/v1/fake"
	k8stesting "k8s.io/client-go/testing"

	client "sigs.k8s.io/apiserver-network-proxy/konnectivity-client/proto/client"
	agentmock "sigs.k8s.io/apiserver-network-proxy/proto/agent/mocks"
	"sigs.k8s.io/apiserver-network-proxy/proto/header"
)

func TestAgentTokenAuthenticationErrorsToken(t *testing.T) {
	stub := gomock.NewController(t)
	defer stub.Finish()

	ns := "test_ns"
	sa := "test_sa"

	testCases := []struct {
		desc               string
		mdKey              string
		tokens             []string
		wantNamespace      string
		wantServiceAccount string
		authenticated      bool
		authError          string
		tokenReviewError   error
		wantError          bool
	}{
		{
			desc:      "no context",
			wantError: true,
		},
		{
			desc:      "non valid metadata key",
			mdKey:     "someKey",
			tokens:    []string{"token1"},
			wantError: true,
		},
		{
			desc:      "non valid token prefix",
			mdKey:     header.AuthenticationTokenContextKey,
			tokens:    []string{"token1"},
			wantError: true,
		},
		{
			desc:      "multiple valid tokens",
			mdKey:     header.AuthenticationTokenContextKey,
			tokens:    []string{header.AuthenticationTokenContextSchemePrefix + "token1", header.AuthenticationTokenContextSchemePrefix + "token2"},
			wantError: true,
		},
		{
			desc:               "not authenticated",
			authenticated:      false,
			mdKey:              header.AuthenticationTokenContextKey,
			tokens:             []string{header.AuthenticationTokenContextSchemePrefix + "token1"},
			wantNamespace:      ns,
			wantServiceAccount: sa,
			wantError:          true,
		},
		{
			desc:               "tokenReview error",
			authenticated:      false,
			mdKey:              header.AuthenticationTokenContextKey,
			tokens:             []string{header.AuthenticationTokenContextSchemePrefix + "token1"},
			tokenReviewError:   fmt.Errorf("some error"),
			wantNamespace:      ns,
			wantServiceAccount: sa,
			wantError:          true,
		},
		{
			desc:               "non valid namespace",
			authenticated:      true,
			mdKey:              header.AuthenticationTokenContextKey,
			tokens:             []string{header.AuthenticationTokenContextSchemePrefix + "token1"},
			wantNamespace:      "_" + ns,
			wantServiceAccount: sa,
			wantError:          true,
		},
		{
			desc:               "non valid service account",
			authenticated:      true,
			mdKey:              header.AuthenticationTokenContextKey,
			tokens:             []string{header.AuthenticationTokenContextSchemePrefix + "token1"},
			wantNamespace:      ns,
			wantServiceAccount: "_" + sa,
			wantError:          true,
		},
		{
			desc:               "authorization succeed",
			authenticated:      true,
			mdKey:              header.AuthenticationTokenContextKey,
			tokens:             []string{header.AuthenticationTokenContextSchemePrefix + "token1"},
			wantNamespace:      ns,
			wantServiceAccount: sa,
		},
	}

	for _, tc := range testCases {
		t.Run(tc.desc, func(t *testing.T) {
			kcs := k8sfake.NewSimpleClientset()

			kcs.AuthenticationV1().(*fakeauthenticationv1.FakeAuthenticationV1).Fake.PrependReactor("create", "tokenreviews", func(action k8stesting.Action) (handled bool, ret runtime.Object, err error) {
				tr := &authv1.TokenReview{
					Status: authv1.TokenReviewStatus{
						Authenticated: tc.authenticated,
						Error:         tc.authError,
						User: authv1.UserInfo{
							Username: fmt.Sprintf("system:serviceaccount:%v:%v", ns, sa),
						},
					},
				}
				return true, tr, tc.tokenReviewError
			})

			var md metadata.MD
			for _, token := range tc.tokens {
				md = metadata.Join(md, metadata.Pairs(tc.mdKey, token))
			}

			md = metadata.Join(md, metadata.Pairs(header.AgentID, ""))

			ctx := context.Background()
			defer ctx.Done()
			ctx = metadata.NewIncomingContext(ctx, md)
			conn := agentmock.NewMockAgentService_ConnectServer(stub)
			conn.EXPECT().Context().AnyTimes().Return(ctx)

			// close agent's connection if no error is expected
			if !tc.wantError {
				conn.EXPECT().SendHeader(gomock.Any()).Return(nil)
				conn.EXPECT().Recv().Return(nil, io.EOF)
			}

			p := NewProxyServer("", []ProxyStrategy{ProxyStrategyDefault}, 1, &AgentTokenAuthenticationOptions{
				Enabled:             true,
				KubernetesClient:    kcs,
				AgentNamespace:      tc.wantNamespace,
				AgentServiceAccount: tc.wantServiceAccount,
			},
				false,
			)

			err := p.Connect(conn)
			if tc.wantError {
				if err == nil {
					t.Errorf("test case expected for error")
				}
			} else {
				if err != nil {
					t.Errorf("did not expected for error but got :%v", err)
				}
			}
		})
	}
}

func TestAddRemoveFrontends(t *testing.T) {
	agent1ConnID1 := new(ProxyClientConnection)
	agent1ConnID2 := new(ProxyClientConnection)
	agent2ConnID1 := new(ProxyClientConnection)
	agent2ConnID2 := new(ProxyClientConnection)
	agent3ConnID1 := new(ProxyClientConnection)

	p := NewProxyServer("", []ProxyStrategy{ProxyStrategyDefault}, 1, nil, false)
	p.addFrontend("agent1", int64(1), agent1ConnID1)
	p.removeFrontend("agent1", int64(1))
	expectedFrontends := make(map[string]map[int64]*ProxyClientConnection)
	if e, a := expectedFrontends, p.frontends; !reflect.DeepEqual(e, a) {
		t.Errorf("expected %v, got %v", e, a)
	}

	p = NewProxyServer("", []ProxyStrategy{ProxyStrategyDefault}, 1, nil, false)
	p.addFrontend("agent1", int64(1), agent1ConnID1)
	p.addFrontend("agent1", int64(2), agent1ConnID2)
	p.addFrontend("agent2", int64(1), agent2ConnID1)
	p.addFrontend("agent2", int64(2), agent2ConnID2)
	p.addFrontend("agent3", int64(1), agent3ConnID1)
	p.removeFrontend("agent2", int64(1))
	p.removeFrontend("agent2", int64(2))
	p.removeFrontend("agent1", int64(1))
	expectedFrontends = map[string]map[int64]*ProxyClientConnection{
		"agent1": {
			int64(2): agent1ConnID2,
		},
		"agent3": {
			int64(1): agent3ConnID1,
		},
	}
	if e, a := expectedFrontends, p.frontends; !reflect.DeepEqual(e, a) {
		t.Errorf("expected %v, got %v", e, a)
	}
}

func prepareFrontendConn(ctrl *gomock.Controller) *agentmock.MockAgentService_ConnectServer {
	// prepare the connection to fontend  of proxy-server
	frontendConn := agentmock.NewMockAgentService_ConnectServer(ctrl)
	frontendConnMD := metadata.MD{
		":authority":   []string{"127.0.0.1:8090"},
		"content-type": []string{"application/grpc"},
		"user-agent":   []string{"grpc-go/1.42.0"},
	}
	frontendConnCtx := metadata.NewIncomingContext(context.Background(), frontendConnMD)
	frontendConn.EXPECT().Context().Return(frontendConnCtx).AnyTimes()
	return frontendConn
}

func prepareAgentConnMD(ctrl *gomock.Controller, proxyServer *ProxyServer) *agentmock.MockAgentService_ConnectServer {
	// prepare the the connection to agent of proxy-server
	agentConn := agentmock.NewMockAgentService_ConnectServer(ctrl)
	agentConnMD := metadata.MD{
		":authority":       []string{"127.0.0.1:8091"},
		"agentid":          []string{uuid.New().String()},
		"agentidentifiers": []string{},
		"content-type":     []string{"application/grpc"},
		"user-agent":       []string{"grpc-go/1.42.0"},
	}
	agentConnCtx := metadata.NewIncomingContext(context.Background(), agentConnMD)
	agentConn.EXPECT().Context().Return(agentConnCtx).AnyTimes()

	_ = proxyServer.addBackend(uuid.New().String(), agentConn)
	return agentConn
}

func baseServerProxyTestWithoutBackend(t *testing.T, validate func(*agentmock.MockAgentService_ConnectServer)) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	frontendConn := prepareFrontendConn(ctrl)
	proxyServer := NewProxyServer(uuid.New().String(), []ProxyStrategy{ProxyStrategyDefault}, 1, &AgentTokenAuthenticationOptions{}, true)

	validate(frontendConn)

	proxyServer.Proxy(frontendConn)

	// add a sleep to make sure `serveRecvFrontend` ends after `Proxy` finished.
	time.Sleep(1 * time.Second)
}

func baseServerProxyTestWithBackend(t *testing.T, validate func(*agentmock.MockAgentService_ConnectServer, *agentmock.MockAgentService_ConnectServer)) {
	ctrl := gomock.NewController(t)
	defer ctrl.Finish()

	frontendConn := prepareFrontendConn(ctrl)

	// prepare proxy server
	proxyServer := NewProxyServer(uuid.New().String(), []ProxyStrategy{ProxyStrategyDefault}, 1, &AgentTokenAuthenticationOptions{}, true)

	agentConn := prepareAgentConnMD(ctrl, proxyServer)

	validate(frontendConn, agentConn)

	proxyServer.Proxy(frontendConn)

	// add a sleep to make sure `serveRecvFrontend` ends after `Proxy` finished.
	time.Sleep(1 * time.Second)
}

func TestServerProxyNoBackend(t *testing.T) {
	validate := func(frontendConn *agentmock.MockAgentService_ConnectServer) {
		// receive DIAL_REQ from frontend and proxy to backend
		dialReq := &client.Packet{
			Type: client.PacketType_DIAL_REQ,
			Payload: &client.Packet_DialRequest{
				DialRequest: &client.DialRequest{
					Protocol: "tcp",
					Address:  "127.0.0.1:8080",
					Random:   111,
				},
			},
		}

		dialResp := &client.Packet{
			Type: client.PacketType_DIAL_RSP,
			Payload: &client.Packet_DialResponse{
				DialResponse: &client.DialResponse{
					Random: 111,
					Error:  (&ErrNotFound{}).Error(),
				}},
		}

		gomock.InOrder(
			frontendConn.EXPECT().Recv().Return(dialReq, nil).Times(1),
			frontendConn.EXPECT().Recv().Return(nil, io.EOF).Times(1),
			// NOTE(mainred): `Send` should come before `Recv` io.EOF, but we cannot add wait between
			//                two Recvs, thus `Recv`` comes before `Send`
			frontendConn.EXPECT().Send(dialResp).Return(nil).Times(1),
		)

	}
	baseServerProxyTestWithoutBackend(t, validate)
}

func TestServerProxyNormalClose(t *testing.T) {
	validate := func(frontendConn, agentConn *agentmock.MockAgentService_ConnectServer) {
		// receive DIAL_REQ from frontend and proxy to backend
		dialReq := &client.Packet{
			Type: client.PacketType_DIAL_REQ,
			Payload: &client.Packet_DialRequest{
				DialRequest: &client.DialRequest{
					Protocol: "tcp",
					Address:  "127.0.0.1:8080",
					Random:   111,
				},
			},
		}

		// recevie CLOSE_REQ from frontend and proxy to backend
		closeReq := &client.Packet{
			Type: client.PacketType_CLOSE_REQ,
			Payload: &client.Packet_CloseRequest{
				CloseRequest: &client.CloseRequest{
					ConnectID: 1,
				}},
		}
		// This extra close is unwanted and should be removed; see
		// https://github.com/kubernetes-sigs/apiserver-network-proxy/pull/307
		extraCloseReq := &client.Packet{
			Type: client.PacketType_CLOSE_REQ,
			Payload: &client.Packet_CloseRequest{
				CloseRequest: &client.CloseRequest{}},
		}

		gomock.InOrder(
			frontendConn.EXPECT().Recv().Return(dialReq, nil).Times(1),
			frontendConn.EXPECT().Recv().Return(closeReq, nil).Times(1),
			frontendConn.EXPECT().Recv().Return(nil, io.EOF).Times(1),
		)
		gomock.InOrder(
			agentConn.EXPECT().Send(dialReq).Return(nil).Times(1),
			agentConn.EXPECT().Send(closeReq).Return(nil).Times(1),
			agentConn.EXPECT().Send(extraCloseReq).Return(nil).Times(1),
		)
	}
	baseServerProxyTestWithBackend(t, validate)
}