[FAB-2640] Gossip: Support empty set of anchor peers

Gossip currently doesn't support an empty set of anchor peers
in the genesis block.
In such a case, it should be assumed that the organization
of the peer is the only member in the channel.

Change-Id: I37e3149076addc6e1e05746488360f700addfee9
Signed-off-by: Yacov Manevich <[email protected]>

Author: yacovm

gossip/gossip/channel/channel.go

@@ -44,6 +44,7 @@ type Config struct {
 	PullPeerNum              int
 	PullInterval             time.Duration
 	RequestStateInfoInterval time.Duration
+	Identity                 api.PeerIdentityType
 }
 
 // GossipChannel defines an object that deals with all channel-related messages
@@ -335,15 +336,22 @@ func (gc *gossipChannel) ConfigureChannel(joinMsg api.JoinChannelMessage) {
 		gc.logger.Warning("Already have a more updated JoinChannel message(", gc.joinMsg.SequenceNumber(), ") than", gc.joinMsg.SequenceNumber())
 		return
 	}
-	orgs := []api.OrgIdentityType{}
+
+	var orgs []api.OrgIdentityType
 	existingOrgInJoinChanMsg := make(map[string]struct{})
+	// We are in the channel if the joinMsg contains an empty set of anchor peers
+	selfOrg := gc.OrgByPeerIdentity(gc.GetConf().Identity)
+	if len(joinMsg.AnchorPeers()) == 0 {
+		orgs = []api.OrgIdentityType{selfOrg}
+	}
 	for _, anchorPeer := range joinMsg.AnchorPeers() {
 		orgID := anchorPeer.OrgID
 		if _, exists := existingOrgInJoinChanMsg[string(orgID)]; !exists {
 			orgs = append(orgs, orgID)
 			existingOrgInJoinChanMsg[string(orgID)] = struct{}{}
 		}
 	}
+
 	gc.orgs = orgs
 	gc.joinMsg = joinMsg
 }

gossip/gossip/channel/channel_test.go

@@ -44,6 +44,7 @@ var conf = Config{
 	PullPeerNum:              3,
 	PullInterval:             time.Second,
 	RequestStateInfoInterval: time.Millisecond * 100,
+	Identity:                 api.PeerIdentityType("pkiIDInOrg1"),
 }
 
 func init() {
@@ -197,8 +198,7 @@ func (ga *gossipAdapterMock) ValidateStateInfoMessage(msg *proto.SignedGossipMes
 }
 
 func (ga *gossipAdapterMock) OrgByPeerIdentity(identity api.PeerIdentityType) api.OrgIdentityType {
-	args := ga.Called(identity)
-	return args.Get(0).(api.OrgIdentityType)
+	return ga.GetOrgOfPeer(common.PKIidType(identity))
 }
 
 func (ga *gossipAdapterMock) GetOrgOfPeer(PKIIID common.PKIidType) api.OrgIdentityType {
@@ -217,6 +217,9 @@ func configureAdapter(adapter *gossipAdapterMock, members ...discovery.NetworkMe
 	adapter.On("GetOrgOfPeer", pkiIDInOrg1ButNotEligible).Return(orgInChannelA)
 	adapter.On("GetOrgOfPeer", pkiIDinOrg2).Return(orgNotInChannelA)
 	adapter.On("GetOrgOfPeer", mock.Anything).Return(api.OrgIdentityType(nil))
+	adapter.On("OrgByPeerIdentity", mock.Anything).Run(func(args mock.Arguments) {
+		fmt.Println(args.Get(0))
+	})
 }
 
 func TestChannelPeriodicalPublishStateInfo(t *testing.T) {
@@ -815,6 +818,35 @@ func TestChannelReconfigureChannel(t *testing.T) {
 	}
 }
 
+func TestChannelNoAnchorPeers(t *testing.T) {
+	t.Parallel()
+
+	// Scenario: We got a join channel message with no anchor peers
+	// In this case, we should be in the channel
+
+	cs := &cryptoService{}
+	adapter := new(gossipAdapterMock)
+	configureAdapter(adapter, discovery.NetworkMember{PKIid: pkiIDInOrg1})
+
+	adapter.On("GetConf").Return(conf)
+	adapter.On("GetMembership").Return([]discovery.NetworkMember{})
+	adapter.On("OrgByPeerIdentity", api.PeerIdentityType(orgInChannelA)).Return(orgInChannelA)
+	adapter.On("GetOrgOfPeer", pkiIDInOrg1).Return(orgInChannelA)
+	adapter.On("GetOrgOfPeer", pkiIDinOrg2).Return(orgNotInChannelA)
+
+	jcm := &joinChanMsg{
+		anchorPeers: func() []api.AnchorPeer {
+			return []api.AnchorPeer{}
+		},
+		getTS: func() time.Time {
+			return time.Now().Add(time.Millisecond * 100)
+		},
+	}
+
+	gc := NewGossipChannel(cs, channelA, adapter, api.JoinChannelMessage(jcm))
+	assert.True(t, gc.IsOrgInChannel(orgInChannelA))
+}
+
 func TestChannelGetPeers(t *testing.T) {
 	t.Parallel()
 

gossip/gossip/chanstate.go

@@ -86,6 +86,7 @@ func (ga *gossipAdapterImpl) GetConf() channel.Config {
 		PullInterval:             ga.conf.PullInterval,
 		PullPeerNum:              ga.conf.PullPeerNum,
 		RequestStateInfoInterval: ga.conf.RequestStateInfoInterval,
+		Identity:                 ga.selfIdentity,
 	}
 }