psql via vagrant ssh with help from knex.js

vpsql

#!/usr/bin/env node

// Usage: vpsql [<environment>] [-- [<psql args>]]
//
// This script looks up the appropriate PostgreSQL database information in your
// local Vagrant development environment and opens a psql session via the
// vagrant ssh command. Without specifying the name of a database (as per your
// knexfile) it will default to "development" or "dev" (whichever exists). In
// addition to that you can pass arbitrary arguments through to the psql command
// by including them after "--".
//
// Examples:
//
//   Connect to your configured `test` database instead of `dev`:
//     $ vpsql test
//
//   Show the schema for `myTable`:
//     $ vpsql -- -c '\d myTable'
//
//   Try out some query:
//     $ vpsql -- -c 'select * from users where id=1;'
//
// Note that psql likes to page larger outputs. If you have a custom PAGER
// environment variable (or specify one when using vpsql) it will be passed in
// through the vagrant ssh call, so you don't need to include unnecessary
// customizations in your VM.
//
// Installation:
// This script should live somewhere in your PATH and run from a directory that
//   1) exists under a vagrant VM directory
//   2) includes a file by the name `knexfile.js`

const fs = require('fs')
const process = require('process')
const childProcess = require('child_process')

let knexFile, knexEnv

function parseArgs(args) {
  const split = args.indexOf('--')
  return split !== -1
    ? [args.slice(0, split), args.slice(split + 1)]
    : [args, []]
}

function psqlCommand(dbEnv, extraArgs) {
  const pager = 'PAGER=${PAGER:-"' + (process.env.PAGER || 'less -S') + '"}'
  const extraArgString = extraArgs.map(arg => `'${arg}'`).join(' ')
  const { connection } = dbEnv

  if (typeof connection === 'string') {
    return `${pager} psql ${connection} ${extraArgString}`
  }

  const { database } = connection
  const user = connection.user || connection.username

  return `${pager} psql -U ${user} -d ${database} ${extraArgString}`
}

try {
  knexFile = require(`${process.cwd()}/knexfile.js`)
} catch (err) {
  console.error('Could not open "knexfile.js". Perhaps you are in the wrong directory?')
  process.exit(1)
}

const [ scriptArgs, extraArgs ] = parseArgs(process.argv.slice(2))
const [ desiredEnv ] = scriptArgs

if (desiredEnv) {
  knexEnv = knexFile[desiredEnv]
} else {
  knexEnv = knexFile.development || knexFile.dev
}

if (!knexEnv) {
  console.error('Could not find an appropriate knex database')
  process.exit(1)
}

childProcess.spawn(
  'vagrant',
  ['ssh', '-c', psqlCommand(knexEnv, extraArgs)],
  { stdio: 'inherit' }
)