fix(lnd): do not require a single lnd process

There is no need to check wether an lnd process exists and prevent
Zap from starting if so. We don't care if there is another process
running. We only care that we can successfully start up our own process.
If there is a conflict with another lnd process such as a port that we
need already being in use we already handle this elsewhere in our code.

app/lib/lnd/util.js

@@ -4,7 +4,6 @@ import axios from 'axios'
 import { promisify } from 'util'
 import { basename, dirname, join, normalize } from 'path'
 import { platform } from 'os'
-import { lookup } from 'ps-node'
 import { app } from 'electron'
 import isDev from 'electron-is-dev'
 import grpc from 'grpc'
@@ -182,27 +181,3 @@ export const createMacaroonCreds = async macaroonPath => {
     callback(null, metadata)
   )
 }
-
-/**
- * Check to see if an LND process is running.
- * @return {Promise} Boolean indicating wether an existing lnd process was found on the host machine.
- */
-export const isLndRunning = () => {
-  return new Promise((resolve, reject) => {
-    mainLog.info('Looking for existing lnd process')
-    lookup({ command: 'lnd' }, (err, results) => {
-      // There was an error checking for the LND process.
-      if (err) {
-        return reject(err)
-      }
-
-      if (!results.length) {
-        // An LND process was found, no need to start our own.
-        mainLog.info('Existing lnd process not found')
-        return resolve(false)
-      }
-      mainLog.info('Found existing lnd process')
-      return resolve(true)
-    })
-  })
-}

app/lib/zap/controller.js

@@ -5,7 +5,6 @@ import pick from 'lodash.pick'
 import Store from 'electron-store'
 import StateMachine from 'javascript-state-machine'
 import { mainLog } from '../utils/log'
-import { isLndRunning } from '../lnd/util'
 
 import LndConfig from '../lnd/config'
 import Lightning from '../lnd/lightning'
@@ -152,22 +151,11 @@ class ZapController {
   onBeforeStartLnd() {
     mainLog.debug('[FSM] onBeforeStartLnd...')
 
-    return isLndRunning().then(res => {
-      if (res) {
-        mainLog.error('lnd already running: %s', res)
-        dialog.showMessageBox({
-          type: 'error',
-          message: 'Unable to start lnd because it is already running.'
-        })
-        return app.quit()
-      }
-
     mainLog.info('Starting new lnd instance')
     mainLog.info(' > alias:', this.lndConfig.alias)
     mainLog.info(' > autopilot:', this.lndConfig.autopilot)
 
     return this.startNeutrino()
-    })
   }
 
   onBeforeConnectLnd() {

package.json

@@ -297,7 +297,6 @@
     "lodash.pick": "^4.4.0",
     "moment": "^2.22.2",
     "prop-types": "^15.6.2",
-    "ps-node": "^0.1.6",
     "qrcode.react": "0.8.0",
     "react": "^16.4.2",
     "react-dom": "^16.4.2",

yarn.lock

@@ -3159,10 +3159,6 @@ connect-history-api-fallback@^1.5.0:
   version "1.5.0"
   resolved "https://registry.yarnpkg.com/connect-history-api-fallback/-/connect-history-api-fallback-1.5.0.tgz#b06873934bc5e344fef611a196a6faae0aee015a"
 
-connected-domain@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/connected-domain/-/connected-domain-1.0.0.tgz#bfe77238c74be453a79f0cb6058deeb4f2358e93"
-
 console-browserify@1.1.x, console-browserify@^1.1.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/console-browserify/-/console-browserify-1.1.0.tgz#f0241c45730a9fc6323b206dbf38edc741d0bb10"
@@ -9604,12 +9600,6 @@ prr@~1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/prr/-/prr-1.0.1.tgz#d3fc114ba06995a45ec6893f484ceb1d78f5f476"
 
-ps-node@^0.1.6:
-  version "0.1.6"
-  resolved "https://registry.yarnpkg.com/ps-node/-/ps-node-0.1.6.tgz#9af67a99d7b1d0132e51a503099d38a8d2ace2c3"
-  dependencies:
-    table-parser "^0.1.3"
-
 pseudomap@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/pseudomap/-/pseudomap-1.0.2.tgz#f052a28da70e618917ef0a8ac34c1ae5a68286b3"
@@ -11524,12 +11514,6 @@ symbol-tree@^3.2.2:
   version "3.2.2"
   resolved "https://registry.yarnpkg.com/symbol-tree/-/symbol-tree-3.2.2.tgz#ae27db38f660a7ae2e1c3b7d1bc290819b8519e6"
 
-table-parser@^0.1.3:
-  version "0.1.3"
-  resolved "https://registry.yarnpkg.com/table-parser/-/table-parser-0.1.3.tgz#0441cfce16a59481684c27d1b5a67ff15a43c7b0"
-  dependencies:
-    connected-domain "^1.0.0"
-
 table@^4.0.1:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/table/-/table-4.0.1.tgz#a8116c133fac2c61f4a420ab6cdf5c4d61f0e435"