Use generated client identifiers (#8034)

* add client identifier generation

* update proto and start fixing tests

* fix ibc tests

* fix auth rest test

* update spec

* fix lint

* add parsing tests and fix bugs

* fix regexp

* add godoc

* address @AdityaSripal review suggestions for identifier parsing

* address rest of @AdityaSripal's review comments

* remove unnecessary comment

* typos

* fix lint

* Apply suggestions from code review

Co-authored-by: Aditya <adityasripal@gmail.com>

* add more heigh tests as per @AdityaSripal suggestion

Co-authored-by: Aditya <adityasripal@gmail.com>

proto/ibc/core/client/v1/genesis.proto

@@ -20,4 +20,6 @@ message GenesisState {
   Params params = 3 [(gogoproto.nullable) = false];
   // create localhost on initialization
   bool create_localhost = 4 [(gogoproto.moretags) = "yaml:\"create_localhost\""];
+  // the sequence for the next generated client identifier
+  uint64 next_client_sequence = 5 [(gogoproto.moretags) = "yaml:\"next_client_sequence\""];
 }

proto/ibc/core/client/v1/tx.proto

@@ -27,15 +27,13 @@ message MsgCreateClient {
   option (gogoproto.equal)           = false;
   option (gogoproto.goproto_getters) = false;
 
-  // client unique identifier
-  string client_id = 1 [(gogoproto.moretags) = "yaml:\"client_id\""];
   // light client state
-  google.protobuf.Any client_state = 2 [(gogoproto.moretags) = "yaml:\"client_state\""];
+  google.protobuf.Any client_state = 1 [(gogoproto.moretags) = "yaml:\"client_state\""];
   // consensus state associated with the client that corresponds to a given
   // height.
-  google.protobuf.Any consensus_state = 3 [(gogoproto.moretags) = "yaml:\"consensus_state\""];
+  google.protobuf.Any consensus_state = 2 [(gogoproto.moretags) = "yaml:\"consensus_state\""];
   // signer address
-  string signer = 4;
+  string signer = 3;
 }
 
 // MsgCreateClientResponse defines the Msg/CreateClient response type.

x/auth/client/rest/rest_test.go

@@ -453,7 +453,6 @@ func (s *IntegrationTestSuite) TestLegacyRestErrMessages() {
 			"Successful IBC message",
 			ibcsolomachinecli.NewCreateClientCmd(),
 			[]string{
-				"21212121212",        // dummy client-id
 				"1",                  // dummy sequence
 				consensusJSON.Name(), // path to consensus json,
 				fmt.Sprintf("--%s=true", flags.FlagSkipConfirmation),

x/ibc/core/02-client/genesis.go

@@ -7,7 +7,6 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/ibc/core/02-client/keeper"
 	"github.com/cosmos/cosmos-sdk/x/ibc/core/02-client/types"
 	"github.com/cosmos/cosmos-sdk/x/ibc/core/exported"
-	localhosttypes "github.com/cosmos/cosmos-sdk/x/ibc/light-clients/09-localhost/types"
 )
 
 // InitGenesis initializes the ibc client submodule's state from a provided genesis
@@ -39,29 +38,10 @@ func InitGenesis(ctx sdk.Context, k keeper.Keeper, gs types.GenesisState) {
 		}
 	}
 
-	if !gs.CreateLocalhost {
-		return
-	}
-
-	// NOTE: return if the localhost client was already imported. The chain-id and
-	// block height will be overwriten to the correct values during BeginBlock.
-	if _, found := k.GetClientState(ctx, exported.Localhost); found {
-		return
-	}
-
-	// client id is always "localhost"
-	revision := types.ParseChainID(ctx.ChainID())
-	clientState := localhosttypes.NewClientState(
-		ctx.ChainID(), types.NewHeight(revision, uint64(ctx.BlockHeight())),
-	)
+	k.SetNextClientSequence(ctx, gs.NextClientSequence)
 
-	if err := clientState.Validate(); err != nil {
-		panic(err)
-	}
-
-	if err := k.CreateClient(ctx, exported.Localhost, clientState, nil); err != nil {
-		panic(err)
-	}
+	// NOTE: localhost creation is specifically disallowed for the time being.
+	// Issue: https://github.com/cosmos/cosmos-sdk/issues/7871
 }
 
 // ExportGenesis returns the ibc client submodule's exported genesis.

x/ibc/core/02-client/keeper/client.go

@@ -15,20 +15,17 @@ import (
 //
 // CONTRACT: ClientState was constructed correctly from given initial consensusState
 func (k Keeper) CreateClient(
-	ctx sdk.Context, clientID string, clientState exported.ClientState, consensusState exported.ConsensusState,
-) error {
+	ctx sdk.Context, clientState exported.ClientState, consensusState exported.ConsensusState,
+) (string, error) {
 	params := k.GetParams(ctx)
 	if !params.IsAllowedClient(clientState.ClientType()) {
-		return sdkerrors.Wrapf(
+		return "", sdkerrors.Wrapf(
 			types.ErrInvalidClientType,
 			"client state type %s is not registered in the allowlist", clientState.ClientType(),
 		)
 	}
 
-	_, found := k.GetClientState(ctx, clientID)
-	if found {
-		return sdkerrors.Wrapf(types.ErrClientExists, "cannot create client with ID %s", clientID)
-	}
+	clientID := k.GenerateClientIdentifier(ctx, clientState.ClientType())
 
 	// check if consensus state is nil in case the created client is Localhost
 	if consensusState != nil {
@@ -46,7 +43,7 @@ func (k Keeper) CreateClient(
 		)
 	}()
 
-	return nil
+	return clientID, nil
 }
 
 // UpdateClient updates the consensus state and the state root from a provided header.