Channel upgradability

.changelog/unreleased/features/ibc-relayer/2547-channel-upgrades.md

@@ -0,0 +1,2 @@
+  - Add support for upgrading channels, as per the [ICS 004 specification](https://github.com/cosmos/ibc/blob/main/spec/core/ics-004-channel-and-packet-semantics/UPGRADES.md) ([#3228](https://github.com/informalsystems/hermes/issues/2547))
+    This feature allows chains to upgrade an existing channel to take advantage of new features without having to create a new channel, thus preserving all existing packet state processed on the channel. For example, a channel could now be upgraded to enable the [ICS 029 fee middleware](https://ibc.cosmos.network/main/middleware/ics29-fee/overview), allowing relayer operators on that channel to receive fees each time they relay an incentivized packet. 

.github/workflows/integration.yaml

@@ -64,7 +64,7 @@ jobs:
             command: simd
             account_prefix: cosmos
             native_token: stake
-            features: ica,ics29-fee
+            features: ica,ics29-fee,channel-upgrade
           - package: wasmd
             command: wasmd
             account_prefix: wasm

crates/relayer-cli/src/commands/tx.rs

@@ -44,6 +44,24 @@ pub enum TxCmd {
     /// Confirm the closing of a channel (ChannelCloseConfirm)
     ChanCloseConfirm(channel::TxChanCloseConfirmCmd),
 
+    /// Relay the channel upgrade attempt (ChannelUpgradeTry)
+    ChanUpgradeTry(channel::TxChanUpgradeTryCmd),
+
+    /// Relay the channel upgrade attempt (ChannelUpgradeAck)
+    ChanUpgradeAck(channel::TxChanUpgradeAckCmd),
+
+    /// Relay the channel upgrade attempt (ChannelUpgradeConfirm)
+    ChanUpgradeConfirm(channel::TxChanUpgradeConfirmCmd),
+
+    /// Relay the channel upgrade attempt (ChannelUpgradeOpen)
+    ChanUpgradeOpen(channel::TxChanUpgradeOpenCmd),
+
+    /// Relay the channel upgrade cancellation (ChannelUpgradeCancel)
+    ChanUpgradeCancel(channel::TxChanUpgradeCancelCmd),
+
+    /// Relay the channel upgrade timeout (ChannelUpgradeTimeout)
+    ChanUpgradeTimeout(channel::TxChanUpgradeTimeoutCmd),
+
     /// Send a fungible token transfer test transaction (ICS20 MsgTransfer)
     FtTransfer(transfer::TxIcs20MsgTransferCmd),