xk6-ethereum

A k6 extension to interact with EVM based blockchains.

Getting started

1. Build or Install BlockSpeed

2. Check the examples folder to learn how to use it

Run and visualize

You can visualize benchmark results in your local machines using the provided Grafana + InfluxDB instance:

docker-compose up -d
xk6 run --out influxdb=http://localhost:8086/blockspeed examples/multiple.js

Navigate to http://localhost:3000/d/BuduMUd4k/blockspeed?orgId=1

Build

To build a k6 binary with this plugin, first ensure you have the prerequisites:

• Go toolchain
• If you're using SQLite, a build toolchain for your system that includes gcc or another C compiler. On Debian and derivatives install the build-essential package. On Windows you can use tdm-gcc. Make sure that gcc is in your PATH.
• Git

Then:

1. Install xk6:

   go install go.k6.io/xk6/cmd/xk6@latest

2. Build the binary:

   xk6 build --with github.com/distribworks/xk6-ethereum

Javascript API

Module k6/x/ethereum

The k6/x/ethereum module contains the Ethereum extension to interact with Ethereum RPC API. To import the module add

import eth from 'k6/x/ethereum';

Class eth.Client({[url, mnemonic, privateKey]})

The class Client is an Ethereum RPC client that can perform several operations to an Ethereum node. The constructor takes the following arguments:

Example:

import eth from 'k6/x/ethereum';
const client = new eth.Client({
    url: 'http://localhost:8545',
});

Methods

• gasPrice() number
• getBalance(address: string, blockNumber: number) number
• blockNumber() number
• getBlockByNumber(block: number, full: boolean) Block
• getNonce(address: string) number
• estimateGas(tx: Transaction) number
• sendTransaction(tx: Transaction) string
• sendRawTransaction(tx: Transaction) string
• getTransactionReceipt(tx_hash: string) Receipt
• waitForTransactionReceipt(tx_hash: string) => Promise<Receipt>
• accounts() string[]
• newContract(address: string, abi: string) Contract
• deployContract(abi: string, bytecode: string, args[]) Receipt

Objects

Transaction
{
  from:        string
  to:          string
  input:       object
  gas_price:   number
  gas_fee_cap: number
  gas_tip_cap: number
  gas:         number
  value:       number
  nonce:       number
  // eip-2930 values
  chain_id: number
}

Receipt
{
  transaction_hash:    object
  transaction_index:   number
  contract_address:    string
  block_hash:          object
  from:                string
  block_number:        number
  gas_used:            number
  cumulative_gas_used: number
  logs_bloom:          object
  logs:                Log[]
  status:              number
}

Log
{
  removed:           bool
  log_index:         number
  transaction_index: number
  transaction_hash:  object
  block_hash:        object
  block_number:      number
  address:           string
  topics:            object[]
  data:              object
}

Contract{}

txn() Receipt
call() object

Metrics

It exposes the following metrics:

• ethereum_block: Blocks in the chain during the test
• ethereum_req_duration: Time taken to perform an API call to the client
• ethereum_tps: Computation of Transactions Per Second mined
• ethereum_time_to_mine: Time it took since a transaction was sent to the client and it has been included in a block

Example

import eth from 'k6/x/ethereum';

const client = new eth.Client({
    url: 'http://localhost:8545',
    // You can also specify a private key here
    // privateKey: 'private key of your account',
    // or a mnemonic
    // mnemonic: 'my mnemonic'
});

// You can use an existing premined account
const root_address = "0x85da99c8a7c2c95964c8efd687e95e632fc533d6"

export function setup() {
  return { nonce: client.getNonce(root_address) };
}

export default function (data) {
  console.log(`nonce => ${data.nonce}`);
  const gas = client.gasPrice();
  console.log(`gas price => ${gas}`);

  const bal = client.getBalance(root_address, client.blockNumber());
  console.log(`bal => ${bal}`);

  const tx = {
    to: "0xDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEF",
    value: Number(0.0001 * 1e18),
    gas_price: gas,
    nonce: data.nonce,
  };

  const txh = client.sendRawTransaction(tx)
  console.log("tx hash => " + txh);
  // Optional: wait for the transaction to be mined
  // const receipt = client.waitForTransactionReceipt(txh).then((receipt) => {
  //   console.log("tx block hash => " + receipt.block_hash);
  //   console.log(typeof receipt.block_number);
  // });
  data.nonce = data.nonce + 1;
}