Codex Trunk

Trunk node for between chains

• Codex Trunk
  • Introduction
    • Design
    • Types
    • Governance
  • Installation
  • Config

Introduction

Trunk is part of the Codex muit-chain system. Some trunk node provides a decentralized state synchronization channel between the two chains. In particular, all chains in codex muit-chain system will have a channel by trunk nodes to codex.relay chain, so every chains can share their state to others by this.

Design

The CODEX relay chain provides relay services between the chains. In the CODEX multi-chain system, chains and chains do not directly interact with each other, but through the CODEX relay chain. For hide the different between chains in the process of cross-chain, we add a 'relay layer' called trunk. Trunk can provide a state transmission channel between any two chains.

Different chains often have different governance structures and economic models,
So the channel in the symmetrical direction will not be equal.

Types

Support two chains called A and B, there are three types of trunk nodes: Committer, Watcher, and Checker,

• Committer : commit chain A block to B
• Watcher : commit chain B state change to A
• Checker : check committers and watchers

Committer can send block to other chain:

Watcher can handler state change from other chain:

Governance

Nodes in trunks need build governance way.

TODO: some examples

Installation

First build the trunk

go get -u -v github.com/codexnetwork/trunk
cd $GOPATH/src/github.com/codexnetwork/trunk
go get -v ./...
go install

You can use -h to get params for trunk:

trunk -h
Usage of ./trunk:
  -cfg string
    	config file path (default "./config.json")
  -d	run in debug mode

After make a config, can start trunk by:

trunk -cfg /path/to/config.json

Config

Now, we support chain A need connect to codex.relay chain by trunks, chain A is a chain bios by eosio.

By this way, we set the A is side chain, codex.relay is relay chain.

we need start a committer node and a watcher node, committer node config like this:

{
    "chains": [{
        "name": "relay",
        "typ": "forceio",
        "startNum": 10000,
        "p2p": [
            "127.0.0.1:8101"
        ],
        "cfg": {
            "url": "http://127.0.0.1:8001",
            "pri":["5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3"]
        }
    }, {
        "name": "side",
        "typ": "eosio",
        "startNum": 10000,
        "p2p": [
            "192.168.2.180:9001","192.168.2.180:9002","192.168.2.180:9003"
        ],
        "cfg": {
            "url": "http://192.168.2.180:8001",
            "pri":["5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3"]
        }
    }],

    "transfer": [{
        "sideacc": "transferc",
        "relayacc": "testc"
    }],

    "relay":{
        "chain":"a",
        "relaycontract":"rs.contract"
    }
}

First we need to config chain info, there is two chain: A and codex.relay.

A is "side" in config and codex.relay is "relay" in config:

   ...

    "chains": [{
        "name": "relay",
        "typ": "forceio",
        ...
    }, {
        "name": "side",
        "typ": "eosio",
        ...
    }],

    ...

typ is the type to chain:

• eosio : chain boot by eosio
• eosforce : chain boot by eosforce
• forceio : chain boot by codexio, also codex.relay
• enu : the enu chain
• bos : the bos chain
• telos : the telos chain

a chain config is like this in chains array:

   {
        "name": "relay", // "side" or "relay"
        "typ": "forceio", // chain typ
        "startNum": 10000, // start sync block num, some chain has boot for a long time, so it is no need to sync all block
        "p2p": [
            "127.0.0.1:8101" // chain p2p address
        ],
        "cfg": {
            "url": "http://127.0.0.1:8001", // chain http url
            "pri":["5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3"] // pri key for trunker 's account in this chain
        }
    }

committer need two account: in chain A, committer has a account called chain.a.acc, in codex.relay chain, committer has a account called relay.a.acc, so the transfer config will be :

    "transfer": [{
        "sideacc": "chain.a.acc",
        "relayacc": "relay.a.acc"
    }],

and watcher config is like this:

...
    "watcher": [{
        "sideacc":"chain.a.acc",
        "relayacc": "relay.a.acc"
    }],
...

at last, we need config channel info, this should some for all trunks:

    "relay":{
        "chain":"a", // chain channel name
        "relaycontract":"rs.contract" // relay contract in side chain
    }