faucet.js

import express from 'express';
import * as path from 'path'

import { DirectSecp256k1HdWallet } from "@cosmjs/proto-signing";
import { SigningStargateClient } from "@cosmjs/stargate";
import { FrequencyChecker } from './checker';

import conf from './config'

// load config
console.log("loaded config: ", conf)

const app = express()

const checker = new FrequencyChecker(conf)

app.get('/', (req, res) => {
  res.sendFile(path.resolve('./index.html'));
})

app.get('/config.json', async (req, res) => {
  const wallet = await DirectSecp256k1HdWallet.fromMnemonic(conf.sender.mnemonic, conf.sender.option);
  const [firstAccount] = await wallet.getAccounts();
  const project = conf.project
  project.sample = firstAccount.address
  res.send(project);
})

app.get('/send/:address', async (req, res) => {
  const {address} = req.params;
  console.log('request tokens to ', address, req.ip)
  if (address) {
    try {
      if (address.startsWith(conf.sender.option.prefix)) {
        if( await checker.checkAddress(address) && await checker.checkIp(req.ip) ) {
          checker.update(req.ip) // get ::1 on localhost
          sendTx(address).then(ret => {
            console.log('sent tokens to ', address)
            checker.update(address)
            res.send({ result: ret })
          });
        }else {
          res.send({ result: "You requested too often" })
        }
      } else {
        res.send({ result: `Address [${address}] is not supported.` })
      }
    } catch (err) {
      console.error(err);
      res.send({ result: 'Failed, Please contact to admin.' })
    }

  } else {
    // send result
    res.send({ result: 'address is required' });
  }
})

app.listen(conf.port, () => {
  console.log(`Faucet app listening on port ${conf.port}`)
})


async function sendTx(recipient) {
  // const mnemonic = "surround miss nominee dream gap cross assault thank captain prosper drop duty group candy wealth weather scale put";
  const wallet = await DirectSecp256k1HdWallet.fromMnemonic(conf.sender.mnemonic, conf.sender.option);
  const [firstAccount] = await wallet.getAccounts();

  // console.log("sender", firstAccount);

  const rpcEndpoint = conf.blockchain.rpc_endpoint;
  const client = await SigningStargateClient.connectWithSigner(rpcEndpoint, wallet);

  // const recipient = "cosmos1xv9tklw7d82sezh9haa573wufgy59vmwe6xxe5";
  const amount = conf.tx.amount;
  const fee = conf.tx.fee;
  return client.sendTokens(firstAccount.address, recipient, [amount], fee);
}