Web API
- Nikita Puzankov
- Vadim Reutskiy
Issues
- We need to define networking format
- We need to define Iroha Peer entry-points
- We need to support communication with:
- Clients (Web, Android, iOS)
- Bridges (Polkadot)
- Peers (Iroha)
Current status
We already have `Iroha_Network` library crate with plain TCP API to:
- send requests
- listen for requests
Messages encoded via `SCALE` format and send as pure bytes.
iroha:peer:Peer and iroha:torii:Torii currently both use the second `Iroha_Network` API, listening for incoming requests:
As you can see, it's quite similar. Also during discussion with Egor Ivkov we found a way to remove "hardcode" from entry-points.
Proposal
First of all, we want to put listener for incoming Web Requests in one place - `Torii`, while send requests API of `Iroha_Network` crate will be available from several places.
Let's start from the entry-points:
| Entry-point | URI | Implementation | Comments |
|---|---|---|---|
| Client → Peer | |||
| Maintenance | Look Maintenance RFC | ||
| Transactions | /transaction | Torii + Queue | Web API for incoming Transactions with Instructions to execute on the ledger Transactions can be send from Clients, Bridges or other Peers |
| Query | /query | Torii + WSV | Web API for Queries which will work with World State View of the Peer |
| Peer ↔ Peer | |||
| Block synchronization | /block | Torii + Kura | Web API for data synchronization and propagation between Peers |
| Consensus | /vote | Torii + Sumeragi | Web API for consensus voting via Sumeragi logic |
Protocol and Formats
Right now we do not have application layer protocol and use TCP. All protocol related logic is placed inside `Iroha_Network` crate.
This way Torii as a listener and all "senders" can be decoupled from our decision about Protocol (REST/gRPC).
Payload Messages format is defined by Iroha lib and encoded via `SCALE` so it's just bytes in Network Message.
Right now our proposal is to stay with pure TCP, use C ABI for Android/iOS clients. Web API should be discussed with the appropriate team.
Configuration as a Contract
To remove hardcoded handlers in our entry-points we want to use ISI and event triggers.
For example this cases can be implemented in compliance with whitepaper, but without hardcode:
- changes in `Iroha` instances like new `ChangeBlockBuildStepTime`
- `AddPeer` instruction will add new peer to WSV:Peer:Peers
- `ShareNewBlock` event can trigger new block propagation to peers from WSV:Peer:Peers
- `Vote` can be implemented as Instruction
Open Questions
- When Peers send accepted transactions? Right after acceptance or each tick of Block Build Step
- What is the difference between Block commit message handling and Block synchronization
- How to update configuration which requires instance reloading (new address, etc)