connect ganache with web3
var Web3 = require('web3');
var web3 = new Web3('http://localhost:8545');
// or
var web3 = new Web3(new Web3.providers.HttpProvider('http://localhost:8545'));
// change provider
web3.setProvider('ws://localhost:8546');
// or
web3.setProvider(new Web3.providers.WebsocketProvider('ws://localhost:8546'));
// Using the IPC provider in node.js
var net = require('net');
var web3 = new Web3('/Users/myuser/Library/Ethereum/geth.ipc', net); // mac os path
// or
var web3 = new Web3(new Web3.providers.IpcProvider('/Users/myuser/Library/Ethereum/geth.ipc', net)); // mac os path
// on windows the path is: "\\\\.\\pipe\\geth.ipc"
// on linux the path is: "/users/myuser/.ethereum/geth.ipc"