feat(eureka): add CLI to submit MsgProvideCounterparty (#7118)

* wip

* wip

* chore: added description

* fix: fixed lint issues

* address my self-review

* lint

* accept hex-encoded strings for merkle path prefix

* fix build error

---------

Co-authored-by: Carlos Rodriguez <carlos@interchain.io>

modules/core/02-client/client/cli/cli.go

@@ -50,6 +50,7 @@ func NewTxCmd() *cobra.Command {
 		newUpgradeClientCmd(),
 		newSubmitRecoverClientProposalCmd(),
 		newScheduleIBCUpgradeProposalCmd(),
+		newProvideCounterpartyCmd(),
 	)
 
 	return txCmd

modules/core/02-client/client/cli/tx.go

@@ -1,9 +1,11 @@
 package cli
 
 import (
+	"encoding/hex"
 	"fmt"
 	"os"
 	"strconv"
+	"strings"
 
 	"github.com/spf13/cobra"
 
@@ -20,6 +22,7 @@ import (
 	govtypes "github.com/cosmos/cosmos-sdk/x/gov/types"
 
 	"github.com/cosmos/ibc-go/v9/modules/core/02-client/types"
+	commitmenttypesv2 "github.com/cosmos/ibc-go/v9/modules/core/23-commitment/types/v2"
 	"github.com/cosmos/ibc-go/v9/modules/core/exported"
 )
 
@@ -450,3 +453,54 @@ func newScheduleIBCUpgradeProposalCmd() *cobra.Command {
 
 	return cmd
 }
+
+// newProvideCounterpartyCmd defines the command to provide the counterparty to an IBC client.
+func newProvideCounterpartyCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "provide-counterparty [client-identifier] [counterparty-client-identifier] [counterparty-merkle-path-prefix]",
+		Args:  cobra.ExactArgs(3),
+		Short: "provide the counterparty to an IBC client",
+		Long: `Provide the counterparty to an IBC client specified by its client ID.
+The [counterparty-merkle-path-prefix] is a comma-separated list of hex-encoded strings.`,
+		Example: fmt.Sprintf("%s tx %s %s provide-counterparty 07-tendermint-0 07-tendermint-1 696263,657572656b61", version.AppName, exported.ModuleName, types.SubModuleName),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			clientCtx, err := client.GetClientTxContext(cmd)
+			if err != nil {
+				return err
+			}
+
+			clientIdentifier := args[0]
+			counterpartyClientIdentifier := args[1]
+			counterpartyMerklePathPrefix, err := parseMerklePathPrefix(args[2])
+			if err != nil {
+				return err
+			}
+
+			counterparty := types.NewCounterparty(counterpartyClientIdentifier, counterpartyMerklePathPrefix)
+			msg := types.MsgProvideCounterparty{
+				ClientId:     clientIdentifier,
+				Counterparty: counterparty,
+				Signer:       clientCtx.GetFromAddress().String(),
+			}
+			return tx.GenerateOrBroadcastTxCLI(clientCtx, cmd.Flags(), &msg)
+		},
+	}
+
+	flags.AddTxFlagsToCmd(cmd)
+	return cmd
+}
+
+// parseMerklePathPrefix parses a comma-separated list of hex-encoded strings into a MerklePath.
+func parseMerklePathPrefix(merklePathPrefixString string) (commitmenttypesv2.MerklePath, error) {
+	var keyPath [][]byte
+	hexPrefixes := strings.Split(merklePathPrefixString, ",")
+	for _, hexPrefix := range hexPrefixes {
+		prefix, err := hex.DecodeString(hexPrefix)
+		if err != nil {
+			return commitmenttypesv2.MerklePath{}, fmt.Errorf("invalid hex merkle path prefix: %w", err)
+		}
+		keyPath = append(keyPath, prefix)
+	}
+
+	return commitmenttypesv2.MerklePath{KeyPath: keyPath}, nil
+}