feat: emitting an event when handling a client upgrade proposal (backport #1570)

CHANGELOG.md

@@ -47,6 +47,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+* (core/02-client) [\#1570](https://github.com/cosmos/ibc-go/pull/1570) Emitting an event when handling an upgrade client proposal.
 * (app/20-transfer) [\#1680](https://github.com/cosmos/ibc-go/pull/1680) Adds migration to correct any malformed trace path information of tokens with denoms that contains slashes. The transfer module consensus version has been bumped to 2.
 * (app/20-transfer) [\#1730](https://github.com/cosmos/ibc-go/pull/1730) parse the ics20 denomination provided via a packet using the channel identifier format specified by ibc-go.
 

modules/core/02-client/keeper/events.go

@@ -0,0 +1,20 @@
+package keeper
+
+import (
+	"fmt"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+
+	"github.com/cosmos/ibc-go/v2/modules/core/02-client/types"
+)
+
+// EmitUpgradeClientProposalEvent emits an upgrade client proposal event
+func EmitUpgradeClientProposalEvent(ctx sdk.Context, title string, height int64) {
+	ctx.EventManager().EmitEvent(
+		sdk.NewEvent(
+			types.EventTypeUpgradeClientProposal,
+			sdk.NewAttribute(types.AttributeKeyUpgradePlanTitle, title),
+			sdk.NewAttribute(types.AttributeKeyUpgradePlanHeight, fmt.Sprintf("%d", height)),
+		),
+	)
+}

modules/core/02-client/keeper/proposal.go

@@ -105,5 +105,12 @@ func (k Keeper) HandleUpgradeProposal(ctx sdk.Context, p *types.UpgradeProposal)
 
 	// sets the new upgraded client in last height committed on this chain is at plan.Height,
 	// since the chain will panic at plan.Height and new chain will resume at plan.Height
-	return k.upgradeKeeper.SetUpgradedClient(ctx, p.Plan.Height, bz)
+	if err = k.upgradeKeeper.SetUpgradedClient(ctx, p.Plan.Height, bz); err != nil {
+		return err
+	}
+
+	// emitting an event for handling client upgrade proposal
+	EmitUpgradeClientProposalEvent(ctx, p.Title, p.Plan.Height)
+
+	return nil
 }

modules/core/02-client/types/events.go

@@ -8,20 +8,23 @@ import (
 
 // IBC client events
 const (
-	AttributeKeyClientID        = "client_id"
-	AttributeKeySubjectClientID = "subject_client_id"
-	AttributeKeyClientType      = "client_type"
-	AttributeKeyConsensusHeight = "consensus_height"
-	AttributeKeyHeader          = "header"
+	AttributeKeyClientID          = "client_id"
+	AttributeKeySubjectClientID   = "subject_client_id"
+	AttributeKeyClientType        = "client_type"
+	AttributeKeyConsensusHeight   = "consensus_height"
+	AttributeKeyHeader            = "header"
+	AttributeKeyUpgradePlanTitle  = "title"
+	AttributeKeyUpgradePlanHeight = "height"
 )
 
 // IBC client events vars
 var (
-	EventTypeCreateClient         = "create_client"
-	EventTypeUpdateClient         = "update_client"
-	EventTypeUpgradeClient        = "upgrade_client"
-	EventTypeSubmitMisbehaviour   = "client_misbehaviour"
-	EventTypeUpdateClientProposal = "update_client_proposal"
+	EventTypeCreateClient          = "create_client"
+	EventTypeUpdateClient          = "update_client"
+	EventTypeUpgradeClient         = "upgrade_client"
+	EventTypeSubmitMisbehaviour    = "client_misbehaviour"
+	EventTypeUpdateClientProposal  = "update_client_proposal"
+	EventTypeUpgradeClientProposal = "upgrade_client_proposal"
 
 	AttributeValueCategory = fmt.Sprintf("%s_%s", host.ModuleName, SubModuleName)
 )