Official Golang execution layer implementation of the Zond protocol.

This code is a test release. All code, features and documentation are subject to change and may represent a work in progress

For prerequisites and detailed build instructions please read the Installation Instructions.

Building gzond requires both a Go (version 1.21 or later) and a C compiler. You can install them using your favourite package manager. Once the dependencies are installed, run

make gzond

or, to build the full suite of utilities:

make all

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

Going through all the possible command line flags is out of scope here (please see our nascent Zond Testnet docs or consult the geth CLI Wiki page), but we've enumerated a few common parameter combos to get you up to speed quickly on how you can run your own gzond instance.

Minimum:

• CPU with 2+ cores
• 4GB RAM
• 1TB free storage space to sync the Mainnet
• 8 MBit/sec download Internet service

Recommended:

• Fast CPU with 4+ cores
• 16GB+ RAM
• High-performance SSD with at least 1TB of free space
• 25+ MBit/sec download Internet service

By far the most common scenario is people wanting to simply interact with the Zond 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 sync quickly to the current state of the network. To do so:

$ gzond console

This command will:

• Start gzond in snap 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 Zond network, which is very CPU intensive.
• Start the built-in interactive JavaScript console, (via the trailing console subcommand) through which you can interact using web3 methods (note: the web3 version bundled within gzond is very old, and not up to date with official docs), as well as gzond's own management APIs. This tool is optional and if you leave it out you can always attach it to an already running gzond instance with gzond attach.

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

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

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

$ gzond --your-favourite-flags dumpconfig

Docker deployment in development

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

docker run -d --name zond-node -v /Users/alice/zond:/root \
           -p 8545:8545 -p 30303:30303 \
           zond/client-go

This will start gzond in snap-sync mode with a DB memory allowance of 1GB, 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 --http.addr 0.0.0.0, if you want to access RPC from other containers and/or hosts. By default, gzond binds to the local interface and RPC endpoints are not accessible from the outside.

As a developer, sooner rather than later you'll want to start interacting with gzond and the Zond network via your own programs and not manually through the console. To aid this, gzond has built-in support for Ethereum-compatible, JSON-RPC based APIs (standard APIs and gzond 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 gzond, 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:

• --http Enable the HTTP-RPC server
• --http.addr HTTP-RPC server listening interface (default: localhost)
• --http.port HTTP-RPC server listening port (default: 8545)
• --http.api API's offered over the HTTP-RPC interface (default: zond,net,web3)
• --http.corsdomain Comma separated list of domains from which to accept cross origin requests (browser enforced)
• --ws Enable the WS-RPC server
• --ws.addr WS-RPC server listening interface (default: localhost)
• --ws.port WS-RPC server listening port (default: 8546)
• --ws.api API's offered over the WS-RPC interface (default: zond,net,web3)
• --ws.origins Origins from which to accept WebSocket requests
• --ipcdisable Disable the IPC-RPC server
• --ipcapi API's offered over the IPC-RPC interface (default: admin,debug,zond,miner,net,personal,txpool,web3)
• --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 gzond 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 Zond 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!

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.

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,
    "istanbulBlock": 0,
    "berlinBlock": 0,
    "londonBlock": 0
  },
  "alloc": {},
  "coinbase": "0x0000000000000000000000000000000000000000",
  "difficulty": "0x20000",
  "extraData": "",
  "gasLimit": "0x2fefd8",
  "nonce": "0x0000000000000042",
  "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "timestamp": "0x00"
}

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 gzond node with it prior to starting it up to ensure all blockchain parameters are correctly set:

$ gzond init path/to/genesis.json

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 gzond node as a bootnode, but it's the less recommended way.

With the bootnode operational and externally reachable (you can try telnet <ip> <port> to ensure it's indeed reachable), start every subsequent gzond 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.

$ gzond --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.

In a private network setting a single CPU miner instance is more than enough for practical purposes as it can produce a stable stream of blocks at the correct intervals without needing heavy resources (consider running on a single thread, no need for multiple ones either). To start a gzond instance for mining, run it with all your usual flags, extended by:

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

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

Thank you for considering helping 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-zond, please fork, fix, commit and send a pull request for the maintainers to review and merge into the main code base. If you wish to submit more complex changes though, please check up with the core devs first on our Discord Server to ensure those changes are in line with the general philosophy of the project and/or get some early feedback which can make both your efforts much lighter as well as our review and merge procedures quick and simple.

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 main branch.
• Commit messages should be prefixed with the package(s) they modify.
• E.g. "zond, rpc: make trace configs optional"

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