Go Fusion

Official Golang implementation of the FUSION protocol.

FUSION would like to extend its gratitude to the Ethereum Foundation.
FUSION has used the official open-source golang implementation of the Ethereum protocol.

API Reference

The API reference can be found here

Building the source

Building efsn requires both a Go (version 1.11 or later) and a C compiler. You can install them using your favourite package manager.

On Ubuntu 18.04, run these commands to install dependencies:

add-apt-repository ppa:longsleep/golang-backports
apt-get update
apt-get install golang-go build-essential

Once the dependencies are installed, run

make efsn

or, to build the full suite of utilities:

make all

Executables

The go-efsn project comes with several wrappers/executables found in the cmd directory.

Command	Description
efsn	Our main FUSION CLI client. It is the entry point into the FUSION network (main-, test- or private net), capable of running as a full node (default), archive node (retaining all historical state) or a light node (retrieving data live). It can be used by other processes as a gateway into the FUSION network via JSON RPC endpoints exposed on top of HTTP, WebSocket and/or IPC transports. efsn --help for command line options.
bootnode	Stripped down version of our FUSION client implementation that only takes part in the network node discovery protocol, but does not run any of the higher level application protocols. It can be used as a lightweight bootstrap node to aid in finding peers in private networks.
rlpdump	Developer utility tool to convert binary RLP (Recursive Length Prefix) dumps (data encoding used by the FUSION protocol both network as well as consensus wise) to user-friendlier hierarchical representation (e.g. rlpdump --hex CE0183FFFFFFC4C304050583616263).

Running efsn

Going through all the possible command line flags is out of scope here (please see efsn --help),but we've enumerated a few common parameter combos to get you up to speed quickly on how you can run your own efsn instance.

Full node on the FUSION main network

By far the most common scenario is people wanting to simply interact with the FUSION network: create accounts; transfer funds; deploy and interact with contracts. For this particular use-case the user doesn't care about years-old historical data, so we can fast-sync quickly to the current state of the network. To do so:

$ efsn console

This command will:

• Start efsn in full sync mode (default, can be changed with the --syncmode flag), causing it to download more data in exchange for avoiding processing the entire history of the FUSION network, which is very CPU intensive.
• Start up efsn's built-in interactive, (via the trailing console subcommand) through which you can invoke all official [web3 methods] as well as efsn's own management APIs. This tool is optional and if you leave it out you can always attach to an already running efsn instance with efsn attach.

Full node on the FUSION test network

Transitioning towards developers, if you'd like to play around with creating FUSION contracts, you almost certainly would like to do that without any real money involved until you get the hang of the entire system. In other words, instead of attaching to the main network, you want to join the test network with your node, which is fully equivalent to the main network, but with play-FSN only.

$ efsn --testnet console

The console subcommand has the exact same meaning as above and they are equally useful on the testnet too. Please see above for their explanations if you've skipped here.

Specifying the --testnet flag, however, will reconfigure your efsn instance a bit:

• Instead of using the default data directory (~/.fusion on Linux for example), efsn will nest itself one level deeper into a testnet subfolder (~/.fusion/testnet on Linux). Note, on OSX and Linux this also means that attaching to a running testnet node requires the use of a custom endpoint since efsn attach will try to attach to a production node endpoint by default. E.g. efsn attach <datadir>/testnet/efsn.ipc. Windows users are not affected by this.
• Instead of connecting the main FUSION network, the client will connect to the test network, which uses different P2P bootnodes, different network IDs and genesis states.

Note: Although there are some internal protective measures to prevent transactions from crossing over between the main network and test network, you should make sure to always use separate accounts for play-money and real-money. Unless you manually move accounts, efsn will by default correctly separate the two networks and will not make any accounts available between them.

Configuration

As an alternative to passing the numerous flags to the efsn binary, you can also pass a configuration file via:

$ efsn --config /path/to/your_config.toml

To get an idea how the file should look like you can use the dumpconfig subcommand to export your existing configuration:

$ efsn --your-favourite-flags dumpconfig

Docker quick start

One of the quickest ways to get FUSION up and running on your machine is by using Docker:

docker run -d --name fusion -v /home/alice/fusion-node:/root \
           -p 9000:9000 -p 40408:40408 \
           jowenshaw/efsn

This will start efsn in full-sync mode with a DB memory allowance of 1GB just as the above command does. It will also create a persistent volume in your home directory for saving your blockchain as well as map the default ports. There is also an alpine tag available for a slim version of the image.

Do not forget --rpcaddr 0.0.0.0, if you want to access RPC from other containers and/or hosts. By default, efsn binds to the local interface and RPC endpoints is not accessible from the outside.

You can build your own image and run container from it (optional):

# build image
docker build -f Dockerfile -t myefsn .

# run container, you can specify your own <usual-flags> (see `efsn --help`)
docker run -d --name fusion -v /home/alice/fusion-node:/root \
           -p 9000:9000 -p 9001:9001 -p 40408:40408 \
           myefsn --rpc --rpcapi "web3,eth,net,fsn,fsntx" --rpcaddr 0.0.0.0 --rpccorsdomain "*"

Programmatically interfacing efsn nodes

As a developer, sooner rather than later you'll want to start interacting with efsn and the FUSION network via your own programs and not manually through the console. To aid this, efsn has built-in support for a JSON-RPC based APIs (standard APIs and efsn specific APIs). These can be exposed via HTTP, WebSockets and IPC (UNIX sockets on UNIX based platforms, and named pipes on Windows).

The IPC interface is enabled by default and exposes all the APIs supported by efsn, whereas the HTTP and WS interfaces need to manually be enabled and only expose a subset of APIs due to security reasons. These can be turned on/off and configured as you'd expect.

HTTP based JSON-RPC API options:

• --rpc Enable the HTTP-RPC server
• --rpcaddr HTTP-RPC server listening interface (default: localhost)
• --rpcport HTTP-RPC server listening port (default: 9000)
• --rpcapi API's offered over the HTTP-RPC interface
• --rpccorsdomain Comma separated list of domains from which to accept cross origin requests (browser enforced)
• --ws Enable the WS-RPC server
• --wsaddr WS-RPC server listening interface (default: localhost)
• --wsport WS-RPC server listening port (default: 9001)
• --wsapi API's offered over the WS-RPC interface
• --wsorigins Origins from which to accept websockets requests
• --ipcdisable Disable the IPC-RPC server
• --ipcpath Filename for IPC socket/pipe within the datadir (explicit paths escape it)

You'll need to use your own programming environments' capabilities (libraries, tools, etc) to connect via HTTP, WS or IPC to a efsn node configured with the above flags and you'll need to speak JSON-RPC on all transports. You can reuse the same connection for multiple requests!

Note: Please understand the security implications of opening up an HTTP/WS based transport before doing so! Hackers on the internet are actively trying to subvert FUSION nodes with exposed APIs! Further, all browser tabs can access locally running web servers, so malicious web pages could try to subvert locally available APIs!

For security, efsn forbid unlock account when account-related RPCs are exposed by http. If you still want to do this, please add the following option to start up efsn:

--allow-insecure-unlock             Allow insecure account unlocking when account-related RPCs are exposed by http

Operating a private network

For devnet private network, please refer Deploy private chain

Maintaining your own private network is more involved as a lot of configurations taken for granted in the official networks need to be manually set up.

Defining the private genesis state

First, you'll need to create the genesis state of your networks, which all nodes need to be aware of and agree upon. This consists of a small JSON file (e.g. call it genesis.json):

{
  "config": {
    "chainId": <arbitrary positive integer>,
    "homesteadBlock": 0,
    "eip150Block": 0,
    "eip155Block": 0,
    "eip158Block": 0,
    "byzantiumBlock": 0,
    "constantinopleBlock": 0,
    "petersburgBlock": 0,
    "DaTong": {
      "period": 15
    }
  },
  "ticketsCreate": {
    "owner": "0x0000000000000000000000000000000000000001",
    "count": 5,
    "time": 1586434131
  },
  "alloc": {},
  "coinbase": "0x0000000000000000000000000000000000000000",
  "difficulty": "0x20000",
  "extraData": "",
  "gasLimit": "0x2fefd8",
  "nonce": "0x0000000000000042",
  "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "timestamp": "0x00"
}

the ticketsCreate field must be specified to trigger mining where owner is the initial miner address, count is the initial number of tickets, and time is the start time of these tickets (normally near to now when you start this chain)

The above fields should be fine for most purposes, although we'd recommend changing the nonce to some random value so you prevent unknown remote nodes from being able to connect to you. If you'd like to pre-fund some accounts for easier testing, create the accounts and populate the alloc field with their addresses.

"alloc": {
  "0x0000000000000000000000000000000000000001": {
    "balance": "111111111"
  },
  "0x0000000000000000000000000000000000000002": {
    "balance": "222222222"
  }
}

With the genesis state defined in the above JSON file, you'll need to initialize every efsn node with it prior to starting it up to ensure all blockchain parameters are correctly set:

$ efsn init path/to/genesis.json

Creating the rendezvous point

With all nodes that you want to run initialized to the desired genesis state, you'll need to start a bootstrap node that others can use to find each other in your network and/or over the internet. The clean way is to configure and run a dedicated bootnode:

$ bootnode --genkey=boot.key
$ bootnode --nodekey=boot.key

With the bootnode online, it will display an enode URL that other nodes can use to connect to it and exchange peer information. Make sure to replace the displayed IP address information (most probably [::]) with your externally accessible IP to get the actual enode URL.

Note: You could also use a full-fledged efsn node as a bootnode, but it's the less recommended way.

Starting up your member nodes

With the bootnode operational and externally reachable (you can try telnet <ip> <port> to ensure it's indeed reachable), start every subsequent efsn node pointed to the bootnode for peer discovery via the --bootnodes flag. It will probably also be desirable to keep the data directory of your private network separated, so do also specify a custom --datadir flag.

$ efsn --datadir=path/to/custom/data/folder --bootnodes=<bootnode-enode-url-from-above>

Note: Since your network will be completely cut off from the main and test networks, you'll also need to configure a miner to process transactions and create new blocks for you.

Running a private miner

To start a efsn instance for mining, run it with all your usual flags, extended by:

$ efsn <usual-flags> --mine --miner.threads=1 --etherbase=0x0000000000000000000000000000000000000000

Which will start mining blocks and transactions on a single CPU thread, crediting all proceedings to the account specified by --etherbase. You can further tune the mining by changing the default gas limit blocks converge to (--targetgaslimit) and the price transactions are accepted at (--gasprice).

Contribution

Thank you for considering to help out with the source code! We welcome contributions from anyone on the internet, and are grateful for even the smallest of fixes!

If you'd like to contribute to go-efsn, please fork, fix, commit and send a pull request for the maintainers to review and merge into the main code base.

Please make sure your contributions adhere to our coding guidelines:

• Code must adhere to the official Go formatting guidelines (i.e. uses gofmt).
• Code must be documented adhering to the official Go commentary guidelines.
• Pull requests need to be based on and opened against the master branch.
• Commit messages should be prefixed with the package(s) they modify.
  • E.g. "eth, rpc: make trace configs optional"

Please see the Developers' Guide for more details on configuring your environment, managing project dependencies, and testing procedures.

License

The go-efsn library (i.e. all code outside of the cmd directory) is licensed under the GNU Lesser General Public License v3.0, also included in our repository in the COPYING.LESSER file.

The go-efsn binaries (i.e. all code inside of the cmd directory) is licensed under the GNU General Public License v3.0, also included in our repository in the COPYING file.