truffle-config.js

const path = require("path");
const HDWalletProvider = require('truffle-hdwallet-provider');
const fs = require('fs');
const mnemonic = fs.readFileSync(".secret").toString().trim();
var networkId = process.env.npm_package_config_ganache_networkId;
var gasPrice = process.env.npm_package_config_ganache_gasPrice;
var gasLimit = process.env.npm_package_config_ganache_gasLimit;


module.exports = {
  // See <http://truffleframework.com/docs/advanced/configuration>
  // to customize your Truffle configuration!
  contracts_build_directory: path.join(__dirname, "client/src/contracts"),
  networks: {
    development: {
      host: "127.0.0.1",
      port: 8545,
      network_id: "*", // Match any network id
      gas: gasLimit,
      gasPrice: gasPrice
    },
    matic: {
      provider: () =>
      new HDWalletProvider(mnemonic, `https://rpc-mumbai.matic.today`),
        network_id: 80001,
        confirmations: 2,
        timeoutBlocks: 200,
        skipDryRun: true,
    },
  },
  compilers: {
    solc: {
      version: "0.6.12",
      optimizer: {
        enabled: true,
        runs: 200,
      },
    },
  }
};