[r2r] cosmos ibc transfer implementation

[onur-ozkan]

Implements:

• one of the Cosmos integration. #1432 (comment) task
• Created mm2_git crate
• Implemented ibc_withdraw, ibc_chains and ibc_transfer_channels RPC methods

This implementation requires chain_registry_name field to be added in coins configuration. It's an optional field, so if chain doesn't have directory in the repository, we can simply leave it as it is.
e.g:

  {
    "coin":"IRIS-TEST",
    "avg_blocktime": 5,
    "protocol":{
      "type":"TENDERMINT",
      "protocol_data":{
        "decimals":6,
        "denom":"unyan",
        "account_prefix":"iaa",
        "chain_id":"nyancat-9",
        "chain_registry_name":"irisnet"
      }
    }
  }

We need this field so we can find the proper path of chains to find informations in cosmos/chain-registry repository.

Examples of implemented RPC methods

ibc_chains

List of cosmos chains that supports IBC operations.

curl -v --url "http://127.0.0.1:7783" -s --data '{
	"userpass": "'$userpass'",
	"mmrpc": "2.0",
	"method": "ibc_chains",
	"id": 0
}'

ibc_transfer_channels

Get IBC channel for doing IBC operation (useful for people who doesn't want to check channels manually from cosmos chains)

curl -v --url "http://127.0.0.1:7783" -s --data '{
	"userpass": "'$userpass'",
	"mmrpc": "2.0",
	"method": "ibc_transfer_channels",
  	"params": {
		"coin": "IRIS-TEST",
		"destination_chain_registry_name": "osmosis" // a chain name from ibc_chains response
	},
	"id": 0
}'

ibc_withdraw

Just a witdhdraw, but through the cosmos IBC channels.

curl -v --url "http://127.0.0.1:7783" -s --data '{
	"userpass": "'$userpass'",
	"mmrpc": "2.0",
	"method": "ibc_withdraw",
	"params": {
		"ibc_source_channel": "channel-81", // IBC source channel(also known as channel id) to use for withdraw operation
		"coin": "IRIS-TEST",
		"to": "cosmos1r5v5srda7xfth3hn2s26txvrcrntldjumt8mhl",
		"amount": "1",
		"memo": "asd"
	},
	"id": 0
}'

[shamardy]

Amazing work as always! Just a few questions/suggestions at this stage of the review :)

[shamardy]

Parts of this function and the ibc_withdraw function for tendermint_coin can probably be made into a common function, do you think this is a good idea?

[onur-ozkan]

I already unified their shared flows, but I realized if I do it too much, it will be harder to debug and maintain.

It's even worst if we combine them into single function because their fee calculations are pretty different.

[shamardy]

Using a trait with some common implementations alongside the builder pattern might work in this case, similar to UtxoWithdraw
https://github.com/KomodoPlatform/atomicDEX-API/blob/dcba19bf11a1e29602cffc291d41808c36775b21/mm2src/coins/utxo/utxo_withdraw.rs#L93
It's up to you in the end, since this suggestion might have some drawbacks too. Just please consider this refactor in next PRs, since more withdraw methods might be added in the future if hardware wallet is to be implemented for tendermint.

[shamardy]

Thanks a lot for the fixes! Only non-blocker question.

[borngraced]

Great work! 🔥

[laruh]

Awesome job!
I just have a small note. Could you please fix this typo? :) I think its contains

[shamardy]

Re-approve

[caglaryucekaya]

You can add some additional checks to this test to make sure that the transaction does what it's supposed to do, e.g. you can compare the balances of the sender and the receiver before/after the send_raw_transaction. I see that the PR is merged now so you can do it on the next PR.

[onur-ozkan]

the relayer I used in this test doesn't work properly on testnet, that's why I couldn't compare balances. So either we have to deploy relayer for testnet that works properly, or use nucleus chain for this specific test because it works without any issue

[shamardy]

Sorry, didn't know you were reviewing this. I merged it since it got the minimum of 2 approvals and was under review for a long time. From now on we should be adding only 2 reviewers on a PR (1 is also enough for a small PR), if someone doesn't plan to review a PR, they can remove themselves and another team member can review it instead :)

[caglaryucekaya]

Yeah no problem, I only had this one comment anyways.

[smk762]

@onur-ozkan I just noticed these methods are not documented. Can you please provide a description of each method and its parameters used in your examples?

Docs issue: KomodoPlatform/komodo-docs-mdx#100

[onur-ozkan]

@onur-ozkan I just noticed these methods are not documented. Can you please provide a description of each method and its parameters used in your examples?

Sure, updated the PR description.