Childchain relayer service

[mwaa]

Bounty

Listener and handler functionalities to relay transactions in the child-chains

Scope

• Handler function that receives lock events from CKB relayer service
• Collect validator signatures via contract method collectLock
• Listen for burn/unlock events on childchain
• Once a burn occurs trigger validator signing
• Collect the validator signature via contract method collectUnlock
• Listen for the BurnQuorum event
• Send BurnQuorum event data to CKB relayer service
• Use same json file to configure environment for both relayer services

listener sleep time
url endpoints for child chain
url endpoints for ckb relayer service
current chain mainent/testnet
bridge script hash
etc

Deliverables

• Deploy-able code with instructions on running service
• Service allow's validator to sign transactions for collectUnlock
• Service allow's relay of BurnQuorum to parent bridge

Funding Circle

Nervos

Bounty Owner/Gardener

@mwaa as LeadLink

Roles

bounty gardener: @mwaa / 50 DAI @johannbarbie / 50 DAI
bounty worker: @mwaa / 710 DAI
bounty reviewer: name / 90 DAI

Gardener checklist

• I have attached one of the size- labels to this bounty
• I have submitted this bounty via http://bounty.leapdao.org/viewform
• I have added this bounty to bounty board here https://github.com/orgs/leapdao/projects/6

[johannbarbie]

Use http calls to relay the transactions from indexer to child chain

This actually requires a signing over a lock receipt.

Provide an http endpoint to receive burn transcations from childchain

This requires a service to scan for EVM events on the child chain. Once an event has been found, it should be signed by validators again.

Provide an http endpoint to query bridge balances from the deposit cell

why is this needed?

Provide an http endpoint to receive deposit requests from UI

why is this needed?

@mwaa can you help me understand the above points? specifically i don't see how you integrate with the validator wallet. I'm getting the gut feeling that there is no other way but to write this as a go-lang module to ethermint, otherwise you can't access the wallet of the validators for signing receipts, can you?

[mwaa]

@johannbarbie

• i have updated the ticket to be precise and and only focus on unlock i.e from childchain to parent.
• questions on how validators will sign without using go module answered on Investigate validator signing functionality for the relayer service #39 (comment)
• removed irrelevant scope

No need for validator to manually sign with wallet as they wouldn't be able to do so for even a minimum of 10TPS.
Since the contract collects the signatures 2/3 validators would have to collude to have a fraudulent unlock
In such a case then the auditDelay script would come in play

[mwaa]

Testing of functionality as been forked out to new ticket #55.
Ran out of time because initial child chain bridge contract was not relaying events as expected on ethermint.