Geth-private NPM

geth-private

Quickly setup a local, private Ethereum blockchain.

Features:

Programmatic as well as command-line interface
Automatically enables IPC and RPC/CORS access
Override all options passed to the geth executable.
Execute console commands against the running geth instance.
Logging capture
Works with Mist wallet

## Requirements:

Node.js v4 or above
Geth 1.8+

Installation

I recommend installing geth-private as a global module so that the CLI becomes available in your PATH:

$ npm install -g geth-private

Usage

via command-line

Quickstart

$ geth-private

You should see something like:

geth is now running (pid: 2428).

Etherbase:  8864324ac84c3b6c507591dfabeffdc1ad02e09b
Data folder:  /var/folders/br6x6mlx113235/T/tmp-242211yX

To attach:  geth attach ipc:///var/folders/br6x6mlx113235/T/tmp-242211yX/geth.ipc

Note: geth-private runs Geth on port 60303 (and HTTP RPC on port 58545) by default with networkid 33333

Run the attach command given to attach a console to this running geth instance. By default web3 RPC is also enabled on port 58545.

Once it's running launch the Ethereum/Mist wallet with the --rpc http://localhost:58545 CLI option - it should be able to connect to your geth instance.

Options

Usage: geth-private [options]

Options:
  --gethPath      Path to geth executable to use instead of default
  -v              Verbose logging
  -h, --help      Show help                                                [boolean]
  --version       Output version.

All other options get passed onto the geth executable.

You can also pass options directly to geth. For example, you can customize network identity, port, etc:

$ geth-private --port 10023 --networkid 54234 --identity testnetwork

By default geth-private stores its keystore and blockchain data inside a temporarily generated folder, which gets automatically deleted once it exits. You can override this behaviour by providing a custom location using the datadir option:

$ geth-private --datadir /path/to/data/folder

When geth-private exits it won't auto-delete this data folder since you manually specified it. This allows you to re-use once created keys and accounts easily.

via API

var geth = require('geth-private');

var inst = geth();

inst.start()
  .then(function() {
    // do some work
  });
  .then(function() {
    // stop it
    return inst.stop();
  });
  .catch(function(err) {
    console.error(err);
  })

Same as for the CLI, you can customize it by passing options during construction:

var geth = require('geth-private');

var inst = geth({
  balance: 10,
  gethPath: '/path/to/geth',
  verbose: true,
  gethOptions: {
    /*
      These options get passed to the geth command-line

      e.g.

      mine: true
      rpc: false,
      identity: 'testnetwork123'
    */
  },
});

inst.start().then(...);

You can execute web3 commands against the running geth instance:

var inst = geth();

inst.start()
  .then(() => {
    return inst.consoleExec('web3.version.api');
  })
  .then((version) => {
    console.log(version);
  })
  ...

Mining

To start and stop mining:

var inst = geth();

inst.start()
  .then(() => {
    return inst.consoleExec('miner.start()');
  })
  ...
  .then(() => {
    return inst.consoleExec('miner.stop()');
  })
  ...

If you've never mined before then Geth will first generate a DAG, which could take a while. Use the -v option to Geth's logging.

Logging capture

When using the programmatic API you can capture all output logging by passing a custom logging object:

var inst = geth({
  verbose: true,
  logger: {
    debug: function() {...},
    info: function() {...},
    error: function() {...}
  }
});

inst.start();