TechnologyAdvice/glambda

/*
 * Copyright (c) 2015 TechnologyAdvice
 */

/* eslint no-process-exit: 0, no-console: 0 */
const util = require('util')
const path = require('path')

// Override console.log to send messages back through proc emit
console.log = console.info = console.warn = console.error = console.debug = (...args) => {
  process.send({
    type: 'debug',
    output: {
      lambda: process.argv[2],
      data: args
    }
  })
}

// Sets the lambda from its path
const lambda = require(path.resolve(`${process.env.lambdas}/${process.argv[2]}/index`))

/**
 * Creates the context object passed to lambdas
 * @property context
 */
const context = {
  /**
   * Emit a success message with output
   * @param {Object|String} result The contents of the result
   */
  succeed: (result) => {
    process.send({ type: 'success', output: result })
    context.done()
  },
  /**
   * Emit an error message with output
   * @param {Object|String} error The error object or message
   */
  fail: (error) => {
    process.send({ type: 'error', output: error })
    context.done()
  },
  /**
   * Emit closing metrics and end the lambda process
   */
  done: () => {
    process.send({ type: 'metric', output: {
      lambda: process.argv[2],
      event: process.env.event,
      pid: process.pid,
      memory: util.inspect(process.memoryUsage()),
      time: process.uptime()
    }})
    process.exit()
  }
}

// Call lambda's handler
lambda.handler(JSON.parse(process.env.event), context)