Support Cosmos SDK 0.46 and 0.47 chains side by side

[mzabaluev]

Summary

The relayer should work with chain nodes based on both Cosmos SDK 0.46 / Tendermint 0.34 and Cosmos SDK 0.47 / CometBFT 0.37.

Problem Definition

While the Cosmos ecosystem transitions to Cosmos SDK 0.47, the relayer should be expected to connect chains working on both old and new versions of the protocols and specifications. There are breaking changes in at least CometBFT 0.37, so the issue is more complex than just updating the libraries to the latest protocol and adding a few backward compatibility adaptations.

Proposal

• Update ibc-proto code generation to CometBFT 0.37, Cosmos SDK 0.47 and a compatible revision of ibc-go definitions TBD. Adapt the code using the protocol structures (Update to cosmos-sdk 0.46 and tendermint 0.35 #2213).
• Extend tendermint-rs to interoperate with tendermint RPC 0.34 as a static API variant (that is, no need to support both versions with a single client type).
• Implement support for both old and new (i.e. pre- and post-break) version combinations of Tendermint RPC, Cosmos-SDK and IBC with dynamic selection in ibc and ibc-relayer (the same chain endpoint should be able to dynamically discover the versions used by the node and adapt to the protocol).

Acceptance Criteria

Hermes is able to connect and relay between the following node versions, as confirmed by tests:

• A chain based on Cosmos SDK 0.46
• A chain based on Cosmos SDK 0.47

At least one test run should exercise relaying between SDK 0.46 and 0.47 nodes.

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[adizere]

Is this issue still relevant in its current form?

[webmaster128]

Right before the release, Cosmos SDK 0.46 switched back from Tendermint 0.35 to 0.34. So at least you only need to worry about one Tendermint version for the two SDK versions.

[romac]

Right! I've updated the issue to reflect that, switch from 0.45->0.46 to 0.46->0.47, and update on the progress.