Add sentinel localhost connection end to genesis state (#3040)

modules/core/03-connection/genesis.go

@@ -19,6 +19,9 @@ func InitGenesis(ctx sdk.Context, k keeper.Keeper, gs types.GenesisState) {
 	}
 	k.SetNextConnectionSequence(ctx, gs.NextConnectionSequence)
 	k.SetParams(ctx, gs.Params)
+
+	localhostConnection := k.CreateSentinelLocalhostConnection()
+	k.SetConnection(ctx, types.LocalhostID, localhostConnection)
 }
 
 // ExportGenesis returns the ibc connection submodule's exported genesis.

modules/core/03-connection/keeper/grpc_query_test.go

@@ -87,9 +87,12 @@ func (suite *KeeperTestSuite) TestQueryConnection() {
 }
 
 func (suite *KeeperTestSuite) TestQueryConnections() {
+	localhostConnectionEnd := suite.chainA.App.GetIBCKeeper().ConnectionKeeper.CreateSentinelLocalhostConnection()
+	localhostConn := types.NewIdentifiedConnection(types.LocalhostID, localhostConnectionEnd)
+
 	var (
 		req            *types.QueryConnectionsRequest
-		expConnections = []*types.IdentifiedConnection{}
+		expConnections = []*types.IdentifiedConnection{&localhostConn}
 	)
 
 	testCases := []struct {
@@ -137,11 +140,11 @@ func (suite *KeeperTestSuite) TestQueryConnections() {
 				iconn2 := types.NewIdentifiedConnection(path2.EndpointA.ConnectionID, conn2)
 				iconn3 := types.NewIdentifiedConnection(path3.EndpointA.ConnectionID, conn3)
 
-				expConnections = []*types.IdentifiedConnection{&iconn1, &iconn2, &iconn3}
+				expConnections = []*types.IdentifiedConnection{&iconn1, &iconn2, &iconn3, &localhostConn}
 
 				req = &types.QueryConnectionsRequest{
 					Pagination: &query.PageRequest{
-						Limit:      3,
+						Limit:      4,
 						CountTotal: true,
 					},
 				}

modules/core/03-connection/keeper/keeper.go

@@ -208,6 +208,12 @@ func (k Keeper) GetAllConnections(ctx sdk.Context) (connections []types.Identifi
 	return connections
 }
 
+// CreateSentinelLocalhostConnection returns the sentinel localhost connection end.
+func (k Keeper) CreateSentinelLocalhostConnection() types.ConnectionEnd {
+	counterparty := types.NewCounterparty(exported.Localhost, types.LocalhostID, commitmenttypes.NewMerklePrefix(k.GetCommitmentPrefix().Bytes()))
+	return types.NewConnectionEnd(types.OPEN, exported.Localhost, counterparty, types.ExportedVersionsToProto(types.GetCompatibleVersions()), 0)
+}
+
 // addConnectionToClient is used to add a connection identifier to the set of
 // connections associated with a client.
 func (k Keeper) addConnectionToClient(ctx sdk.Context, clientID, connectionID string) error {

modules/core/03-connection/keeper/keeper_test.go

@@ -7,6 +7,7 @@ import (
 	"github.com/stretchr/testify/suite"
 
 	"github.com/cosmos/ibc-go/v7/modules/core/03-connection/types"
+	commitmenttypes "github.com/cosmos/ibc-go/v7/modules/core/23-commitment/types"
 	"github.com/cosmos/ibc-go/v7/modules/core/exported"
 	ibctesting "github.com/cosmos/ibc-go/v7/testing"
 )
@@ -79,7 +80,10 @@ func (suite KeeperTestSuite) TestGetAllConnections() { //nolint:govet // this is
 	iconn1 := types.NewIdentifiedConnection(path1.EndpointA.ConnectionID, conn1)
 	iconn2 := types.NewIdentifiedConnection(path2.EndpointA.ConnectionID, conn2)
 
-	expConnections := []types.IdentifiedConnection{iconn1, iconn2}
+	localhostConnectionEnd := suite.chainA.App.GetIBCKeeper().ConnectionKeeper.CreateSentinelLocalhostConnection()
+	localhostConn := types.NewIdentifiedConnection(types.LocalhostID, localhostConnectionEnd)
+
+	expConnections := []types.IdentifiedConnection{iconn1, iconn2, localhostConn}
 
 	connections := suite.chainA.App.GetIBCKeeper().ConnectionKeeper.GetAllConnections(suite.chainA.GetContext())
 	suite.Require().Len(connections, len(expConnections))
@@ -156,3 +160,19 @@ func (suite *KeeperTestSuite) TestGetTimestampAtHeight() {
 		})
 	}
 }
+
+func (suite *KeeperTestSuite) TestLocalhostConnectionEndCreation() {
+	ctx := suite.chainA.GetContext()
+	connectionKeeper := suite.chainA.App.GetIBCKeeper().ConnectionKeeper
+	localhostConnection := connectionKeeper.CreateSentinelLocalhostConnection()
+	connectionKeeper.SetConnection(ctx, types.LocalhostID, localhostConnection)
+
+	connectionEnd, found := connectionKeeper.GetConnection(ctx, types.LocalhostID)
+
+	suite.Require().True(found)
+	suite.Require().Equal(types.OPEN, connectionEnd.State)
+	suite.Require().Equal(exported.Localhost, connectionEnd.ClientId)
+	suite.Require().Equal(types.ExportedVersionsToProto(types.GetCompatibleVersions()), connectionEnd.Versions)
+	expectedCounterParty := types.NewCounterparty(exported.Localhost, types.LocalhostID, commitmenttypes.NewMerklePrefix(connectionKeeper.GetCommitmentPrefix().Bytes()))
+	suite.Require().Equal(expectedCounterParty, connectionEnd.Counterparty)
+}

modules/core/03-connection/keeper/migrations.go

@@ -0,0 +1,24 @@
+package keeper
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+
+	connectionv7 "github.com/cosmos/ibc-go/v7/modules/core/03-connection/migrations/v7"
+)
+
+// Migrator is a struct for handling in-place store migrations.
+type Migrator struct {
+	keeper Keeper
+}
+
+// NewMigrator returns a new Migrator.
+func NewMigrator(keeper Keeper) Migrator {
+	return Migrator{keeper: keeper}
+}
+
+// Migrate3to4 migrates from version 3 to 4.
+// This migration writes the sentinel localhost connection end to state.
+func (m Migrator) Migrate3to4(ctx sdk.Context) error {
+	connectionv7.MigrateLocalhostConnection(ctx, m.keeper)
+	return nil
+}

modules/core/03-connection/migrations/v7/expected_keepers.go

@@ -0,0 +1,13 @@
+package v7
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+
+	"github.com/cosmos/ibc-go/v7/modules/core/03-connection/types"
+)
+
+// ConnectionKeeper expected IBC connection keeper
+type ConnectionKeeper interface {
+	CreateSentinelLocalhostConnection() types.ConnectionEnd
+	SetConnection(ctx sdk.Context, connectionID string, connection types.ConnectionEnd)
+}

modules/core/03-connection/migrations/v7/localhost.go

@@ -0,0 +1,14 @@
+package v7
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+
+	connectiontypes "github.com/cosmos/ibc-go/v7/modules/core/03-connection/types"
+)
+
+// MigrateLocalhostConnection creates the sentinel localhost connection end to enable
+// localhost ibc functionality.
+func MigrateLocalhostConnection(ctx sdk.Context, connectionKeeper ConnectionKeeper) {
+	localhostConnection := connectionKeeper.CreateSentinelLocalhostConnection()
+	connectionKeeper.SetConnection(ctx, connectiontypes.LocalhostID, localhostConnection)
+}

modules/core/module.go

@@ -19,6 +19,7 @@ import (
 	ibcclient "github.com/cosmos/ibc-go/v7/modules/core/02-client"
 	clientkeeper "github.com/cosmos/ibc-go/v7/modules/core/02-client/keeper"
 	clienttypes "github.com/cosmos/ibc-go/v7/modules/core/02-client/types"
+	connectionkeeper "github.com/cosmos/ibc-go/v7/modules/core/03-connection/keeper"
 	connectiontypes "github.com/cosmos/ibc-go/v7/modules/core/03-connection/types"
 	channeltypes "github.com/cosmos/ibc-go/v7/modules/core/04-channel/types"
 	"github.com/cosmos/ibc-go/v7/modules/core/client/cli"
@@ -124,9 +125,13 @@ func (am AppModule) RegisterServices(cfg module.Configurator) {
 	channeltypes.RegisterMsgServer(cfg.MsgServer(), am.keeper)
 	types.RegisterQueryService(cfg.QueryServer(), am.keeper)
 
-	m := clientkeeper.NewMigrator(am.keeper.ClientKeeper)
-	err := cfg.RegisterMigration(exported.ModuleName, 2, m.Migrate2to3)
-	if err != nil {
+	clientMigrator := clientkeeper.NewMigrator(am.keeper.ClientKeeper)
+	if err := cfg.RegisterMigration(exported.ModuleName, 2, clientMigrator.Migrate2to3); err != nil {
+		panic(err)
+	}
+
+	connectionMigrator := connectionkeeper.NewMigrator(am.keeper.ConnectionKeeper)
+	if err := cfg.RegisterMigration(exported.ModuleName, 3, connectionMigrator.Migrate3to4); err != nil {
 		panic(err)
 	}
 }
@@ -150,7 +155,7 @@ func (am AppModule) ExportGenesis(ctx sdk.Context, cdc codec.JSONCodec) json.Raw
 }
 
 // ConsensusVersion implements AppModule/ConsensusVersion.
-func (AppModule) ConsensusVersion() uint64 { return 3 }
+func (AppModule) ConsensusVersion() uint64 { return 4 }
 
 // BeginBlock returns the begin blocker for the ibc module.
 func (am AppModule) BeginBlock(ctx sdk.Context, req abci.RequestBeginBlock) {