InitGenesis in migrations when fromVersion==0

simapp/app.go

@@ -339,7 +339,7 @@ func NewSimApp(
 
 	app.mm.RegisterInvariants(&app.CrisisKeeper)
 	app.mm.RegisterRoutes(app.Router(), app.QueryRouter(), encodingConfig.Amino)
-	app.configurator = module.NewConfigurator(app.MsgServiceRouter(), app.GRPCQueryRouter())
+	app.configurator = module.NewConfigurator(app.appCodec, app.MsgServiceRouter(), app.GRPCQueryRouter())
 	app.mm.RegisterServices(app.configurator)
 
 	// add test gRPC service for testing gRPC queries in isolation
@@ -536,22 +536,6 @@ func (app *SimApp) RegisterTendermintService(clientCtx client.Context) {
 	tmservice.RegisterTendermintService(app.BaseApp.GRPCQueryRouter(), clientCtx, app.interfaceRegistry)
 }
 
-// RunMigrations performs in-place store migrations for all modules. This
-// function MUST be only called by x/upgrade UpgradeHandler.
-//
-// `migrateFromVersions` is a map of moduleName to fromVersion (unit64), where
-// fromVersion denotes the version from which we should migrate the module, the
-// target version being the module's latest ConsensusVersion.
-//
-// Example:
-//   cfg := module.NewConfigurator(...)
-//   app.UpgradeKeeper.SetUpgradeHandler("store-migration", func(ctx sdk.Context, plan upgradetypes.Plan, vm module.VersionMap) {
-//       return app.RunMigrations(ctx, vm)
-//   })
-func (app *SimApp) RunMigrations(ctx sdk.Context, migrateFromVersions module.VersionMap) (module.VersionMap, error) {
-	return app.mm.RunMigrations(ctx, app.configurator, migrateFromVersions)
-}
-
 // RegisterSwaggerAPI registers swagger route with API Server
 func RegisterSwaggerAPI(ctx client.Context, rtr *mux.Router) {
 	statikFS, err := fs.New()

simapp/app_test.go

@@ -5,18 +5,21 @@ import (
 	"os"
 	"testing"
 
+	"github.com/golang/mock/gomock"
 	"github.com/stretchr/testify/require"
 	abci "github.com/tendermint/tendermint/abci/types"
 	"github.com/tendermint/tendermint/libs/log"
 	tmproto "github.com/tendermint/tendermint/proto/tendermint/types"
 	dbm "github.com/tendermint/tm-db"
 
 	"github.com/cosmos/cosmos-sdk/baseapp"
+	"github.com/cosmos/cosmos-sdk/tests/mocks"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/module"
 	"github.com/cosmos/cosmos-sdk/x/auth"
 	"github.com/cosmos/cosmos-sdk/x/auth/vesting"
 	"github.com/cosmos/cosmos-sdk/x/authz"
+	"github.com/cosmos/cosmos-sdk/x/bank"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 	"github.com/cosmos/cosmos-sdk/x/capability"
 	"github.com/cosmos/cosmos-sdk/x/crisis"
@@ -80,7 +83,7 @@ func TestRunMigrations(t *testing.T) {
 	bApp.SetCommitMultiStoreTracer(nil)
 	bApp.SetInterfaceRegistry(encCfg.InterfaceRegistry)
 	app.BaseApp = bApp
-	app.configurator = module.NewConfigurator(app.MsgServiceRouter(), app.GRPCQueryRouter())
+	app.configurator = module.NewConfigurator(app.appCodec, app.MsgServiceRouter(), app.GRPCQueryRouter())
 
 	// We register all modules on the Configurator, except x/bank. x/bank will
 	// serve as the test subject on which we run the migration tests.
@@ -160,8 +163,8 @@ func TestRunMigrations(t *testing.T) {
 			// Run migrations only for bank. That's why we put the initial
 			// version for bank as 1, and for all other modules, we put as
 			// their latest ConsensusVersion.
-			_, err = app.RunMigrations(
-				app.NewContext(true, tmproto.Header{Height: app.LastBlockHeight()}),
+			_, err = app.mm.RunMigrations(
+				app.NewContext(true, tmproto.Header{Height: app.LastBlockHeight()}), app.configurator,
 				module.VersionMap{
 					"bank":         1,
 					"auth":         auth.AppModule{}.ConsensusVersion(),
@@ -185,12 +188,58 @@ func TestRunMigrations(t *testing.T) {
 				require.EqualError(t, err, tc.expRunErrMsg)
 			} else {
 				require.NoError(t, err)
+				// Make sure bank's migration is called.
 				require.Equal(t, tc.expCalled, called)
 			}
 		})
 	}
 }
 
+func TestInitGenesisOnMigration(t *testing.T) {
+	db := dbm.NewMemDB()
+	encCfg := MakeTestEncodingConfig()
+	logger := log.NewTMLogger(log.NewSyncWriter(os.Stdout))
+	app := NewSimApp(logger, db, nil, true, map[int64]bool{}, DefaultNodeHome, 0, encCfg, EmptyAppOptions{})
+	ctx := app.NewContext(true, tmproto.Header{Height: app.LastBlockHeight()})
+
+	// Create a mock module. This module will serve as the new module we're
+	// adding during a migration.
+	mockCtrl := gomock.NewController(t)
+	t.Cleanup(mockCtrl.Finish)
+	mockModule := mocks.NewMockAppModule(mockCtrl)
+	mockDefaultGenesis := json.RawMessage(`{"key": "value"}`)
+	mockModule.EXPECT().DefaultGenesis(gomock.Eq(app.appCodec)).Times(1).Return(mockDefaultGenesis)
+	mockModule.EXPECT().InitGenesis(gomock.Eq(ctx), gomock.Eq(app.appCodec), gomock.Eq(mockDefaultGenesis)).Times(1).Return(nil)
+
+	app.mm.Modules["mock"] = mockModule
+
+	// Run migrations only for "mock" module. That's why we put the initial
+	// version for bank as 0 (to run its InitGenesis), and for all other
+	// modules, we put their latest ConsensusVersion to skip migrations.
+	_, err := app.mm.RunMigrations(ctx, app.configurator,
+		module.VersionMap{
+			"mock":         0,
+			"bank":         bank.AppModule{}.ConsensusVersion(),
+			"auth":         auth.AppModule{}.ConsensusVersion(),
+			"authz":        authz.AppModule{}.ConsensusVersion(),
+			"staking":      staking.AppModule{}.ConsensusVersion(),
+			"mint":         mint.AppModule{}.ConsensusVersion(),
+			"distribution": distribution.AppModule{}.ConsensusVersion(),
+			"slashing":     slashing.AppModule{}.ConsensusVersion(),
+			"gov":          gov.AppModule{}.ConsensusVersion(),
+			"params":       params.AppModule{}.ConsensusVersion(),
+			"upgrade":      upgrade.AppModule{}.ConsensusVersion(),
+			"vesting":      vesting.AppModule{}.ConsensusVersion(),
+			"feegrant":     feegrant.AppModule{}.ConsensusVersion(),
+			"evidence":     evidence.AppModule{}.ConsensusVersion(),
+			"crisis":       crisis.AppModule{}.ConsensusVersion(),
+			"genutil":      genutil.AppModule{}.ConsensusVersion(),
+			"capability":   capability.AppModule{}.ConsensusVersion(),
+		},
+	)
+	require.NoError(t, err)
+}
+
 func TestUpgradeStateOnGenesis(t *testing.T) {
 	encCfg := MakeTestEncodingConfig()
 	db := dbm.NewMemDB()

types/module/configurator.go

@@ -3,6 +3,7 @@ package module
 import (
 	"github.com/gogo/protobuf/grpc"
 
+	"github.com/cosmos/cosmos-sdk/codec"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 )
@@ -34,6 +35,7 @@ type Configurator interface {
 }
 
 type configurator struct {
+	cdc         codec.Marshaler
 	msgServer   grpc.Server
 	queryServer grpc.Server
 
@@ -42,8 +44,9 @@ type configurator struct {
 }
 
 // NewConfigurator returns a new Configurator instance
-func NewConfigurator(msgServer grpc.Server, queryServer grpc.Server) Configurator {
+func NewConfigurator(cdc codec.Marshaler, msgServer grpc.Server, queryServer grpc.Server) Configurator {
 	return configurator{
+		cdc:         cdc,
 		msgServer:   msgServer,
 		queryServer: queryServer,
 		migrations:  map[string]map[uint64]MigrationHandler{},

types/module/module.go

@@ -337,7 +337,31 @@ type MigrationHandler func(sdk.Context) error
 // version from which we should perform the migration for each module.
 type VersionMap map[string]uint64
 
-// RunMigrations performs in-place store migrations for all modules.
+// RunMigrations performs in-place store migrations for all modules. This
+// function MUST be called insde an x/upgrade UpgradeHandler.
+//
+// Recall that in an upgrade handler, the `fromVM` VersionMap is retrieved from
+// x/upgrade's store, and the function needs to return to target VersionMap
+// that will in turn be persisted to the x/upgrade's store. In general,
+// returning RunMigrations should be enough:
+//
+// Example:
+//   cfg := module.NewConfigurator(...)
+//   app.UpgradeKeeper.SetUpgradeHandler("my-plan", func(ctx sdk.Context, plan upgradetypes.Plan, fromVM module.VersionMap) {
+//       return app.mm.RunMigrations(ctx, cfg, fromVM)
+//   })
+//
+// Internally, RunMigrations will perform the following steps:
+// - create an `updatedVM` VersionMap of module with their latest ConsensusVersion
+// - make a diff of `fromVM` and `udpatedVM`, and for each module:
+//    - if the module's `fromVM` version is less than its `updatedVM` version,
+//      then run in-place store migrations for that module between those versions.
+//    - if the module's `fromVM` is 0 (which means that it's a new module,
+//      because it was not in the previous x/upgrade's store), then run
+//      `InitGenesis` on that module.
+// - return the `updatedVM` to be persisted in the x/upgrade's store.
+//
+// Please also refer to docs/core/upgrade.md for more information.
 func (m Manager) RunMigrations(ctx sdk.Context, cfg Configurator, fromVM VersionMap) (VersionMap, error) {
 	c, ok := cfg.(configurator)
 	if !ok {
@@ -349,13 +373,34 @@ func (m Manager) RunMigrations(ctx sdk.Context, cfg Configurator, fromVM Version
 		fromVersion := fromVM[moduleName]
 		toVersion := module.ConsensusVersion()
 
-		// only run migrations when the from version is > 0
-		// from version will be 0 when a new module is added and migrations shouldn't be run in this case
+		// Only run migrations when the fromVersion is > 0, or run InitGenesis
+		// if fromVersion == 0.
+		//
+		// fromVersion will be 0 in two cases:
+		// 1. If a new module is added. In this case we run InitGenesis with an
+		// empty genesis state.
+		// 2. If the app developer is running in-place store migrations for the
+		// first time. In this case, it is the app developer's responsibility
+		// to set their module's fromVersions to a version that suits them.
 		if fromVersion > 0 {
 			err := c.runModuleMigrations(ctx, moduleName, fromVersion, toVersion)
 			if err != nil {
 				return nil, err
 			}
+		} else {
+			cfgtor, ok := cfg.(configurator)
+			if !ok {
+				// Currently, the only implementator of Configurator (the interface)
+				// is configurator (the struct).
+				return nil, sdkerrors.Wrapf(sdkerrors.ErrInvalidType, "expected %T, got %T", configurator{}, cfg)
+			}
+
+			moduleValUpdates := module.InitGenesis(ctx, cfgtor.cdc, module.DefaultGenesis(cfgtor.cdc))
+			// The module manager assumes only one module will update the
+			// validator set, and that it will not be by a new module.
+			if len(moduleValUpdates) > 0 {
+				return nil, sdkerrors.Wrapf(sdkerrors.ErrLogic, "validator InitGenesis updates already set by a previous module")
+			}
 		}
 
 		updatedVM[moduleName] = toVersion

types/module/module_test.go

@@ -179,7 +179,9 @@ func TestManager_RegisterQueryServices(t *testing.T) {
 
 	msgRouter := mocks.NewMockServer(mockCtrl)
 	queryRouter := mocks.NewMockServer(mockCtrl)
-	cfg := module.NewConfigurator(msgRouter, queryRouter)
+	interfaceRegistry := types.NewInterfaceRegistry()
+	cdc := codec.NewProtoCodec(interfaceRegistry)
+	cfg := module.NewConfigurator(cdc, msgRouter, queryRouter)
 	mockAppModule1.EXPECT().RegisterServices(cfg).Times(1)
 	mockAppModule2.EXPECT().RegisterServices(cfg).Times(1)
 

x/upgrade/types/handler.go

@@ -5,5 +5,16 @@ import (
 	"github.com/cosmos/cosmos-sdk/types/module"
 )
 
-// UpgradeHandler specifies the type of function that is called when an upgrade is applied
-type UpgradeHandler func(ctx sdk.Context, plan Plan, vm module.VersionMap) (module.VersionMap, error)
+// UpgradeHandler specifies the type of function that is called when an upgrade
+// is applied.
+//
+// `fromVM` is a VersionMap of moduleName to fromVersion (unit64), where
+// fromVersion denotes the version from which we should migrate the module, the
+// target version being the module's latest version in the return VersionMap,
+// let's call it `toVM`.
+//
+// fromVM is retrieved from x/upgrade's store, whereas `toVM` is chosen
+// arbitrarily by the app developer (and persisted to x/upgrade's store right
+// after the upgrade handler runs). In general, `toVM` should map module names
+// to their latest ConsensusVersion.
+type UpgradeHandler func(ctx sdk.Context, plan Plan, fromVM module.VersionMap) (module.VersionMap, error)