Testnet Mining – High CPU Usage in Testnet Mining

I fixed it. UI front-end now works, pulling contract data through to the browser.

I was not careful with my port references between geth/cors, http-server, and the one referenced in my UI javascript as Péter Szilágyi sniffed out. I list my working steps below to help others trace similar problems:

First: start geth using: geth --rpc --rpccorsdomain="http://localhost:3000" //presuming the UI will be run on port 3000

Second: Launch the http server on the above referenced port. In my case, used the npm installed module 'http-server': http-server -p 3000 //must match the port referenced in rpccorsdomain above.

Third: Made sure web3 was installed with npm. Linked app.js to index.html and included this code at the top:

 var Web3 = require('web3');

// Initialize connection
 var web3 = new Web3(new Web3.providers.HttpProvider('http://127.0.0.1:8545'));  //may want to test for non-existence first per docs
 var ABI = [...]
 var greeterAddress = "..."
 var greeter = web3.eth.contract(ABI).at(greeterAddress);

The problem was in the truffle.js file.

module.exports = {
  networks: {
    rinkeby: {
      network_id: 4,
      host: '127.0.0.1',
      port: 8545,
      gas: 4000000,
      from: <your account address>
    },
  },
  rpc: {
    // Use the default host and port when not using rinkeby
    host: 'localhost',
    port: 8080,
  },
};

Just needed to add a from: <account address> into rinkeby's config information.