custom-notary-flow

Custom Notary Flow

This CorDapp provides a simple example of how to propagate data from Corda to Ethereum by creating a Custom Notary Flow. This case consists of 2 flows and 1 custom notary flow:

• MakeAgreementFlow - Making an agreement between 2 parties
• TerminateAgreementFlow - Terminating the agreement
• CustomValidatingNotaryFlow - Sending a transaction that transfers 1 ether from an account to the other account only if the command is Terminate

Be aware that support of HTTP requests in flows is currently limited:

• The request must be executed in a BLOCKING way. Flows don't currently support suspending to await an HTTP call's response
• The request must be idempotent. If the flow fails and has to restart from a checkpoint, the request will also be replayed

Also, be aware that there is okhttp's dependency conflict between Corda Node v4 and web3j (later than 4.5.12).

Pre-requisites:

See https://docs.corda.net/getting-set-up.html.

Run ganache-cli

ganache-cli is a fast Ethereum RPC client for testing and development.

You can run ganache-cli by following Minimal Ethereum Environment.

Usage

Running the database:

docker run --name postgres96 -e POSTGRES_PASSWORD=password -p 5432:5432 -d postgres:9.6

Running the nodes:

See https://docs.corda.net/tutorial-cordapp.html#running-the-example-cordapp.

Use the deployNodes task and ./build/nodes/runnodes script.

Interacting with the nodes:

You'll be interacting with the node via its interactive shell.

Run MakeAgreementFlow from PartyA:

flow start jp.co.layerx.cordage.customnotaryflow.flows.MakeAgreementFlow target: "O=ParticipantB,L=Tokyo,C=JP", agreementBody: "RESIDENTIAL LEASE AGREEMENT"

Run this from both PartyA and PartyB:

run vaultQuery contractStateType: jp.co.layerx.cordage.customnotaryflow.states.Agreement

Run TerminateAgreementFlow from PartyA or PartyB:

flow start jp.co.layerx.cordage.customnotaryflow.flows.TerminateAgreementFlow linearId: "661504cb-ba74-4bd5-9b93-940201ca7a11"