将 node.js 应用程序部署到 heroku 时出错（找不到模块 dotenv 和 npm ERR！errno 1）答案

【问题标题】：Error while deploying node.js application to heroku (cannot find module dotenv, and npm ERR! errno 1)将 node.js 应用程序部署到 heroku 时出错（找不到模块 dotenv 和 npm ERR！errno 1）
【发布时间】：2021-04-17 11:35:46
【问题描述】：

我正在尝试将我的第一个 node.js 应用程序上传到 heroku。构建显示成功，但无法在浏览器中打开应用程序。这是部署的日志尾部。我不太确定问题出在哪里。使用邮递员进行测试时，所有 localhost 路由实际上都在工作。我使用的是 express 生成器，所以 PORT 是在 .bin/www 中声明的。我也在使用.env。我有点不知道下一步该往哪里看。有什么建议？非常感谢！

2021-01-11T22:10:14.214188+00:00 app[web.1]: > finale-backend@0.0.0 start /app
2021-01-11T22:10:14.214189+00:00 app[web.1]: > node ./bin/www
2021-01-11T22:10:14.214189+00:00 app[web.1]: 
2021-01-11T22:10:14.285451+00:00 app[web.1]: internal/modules/cjs/loader.js:818
2021-01-11T22:10:14.285453+00:00 app[web.1]: throw err;
2021-01-11T22:10:14.285453+00:00 app[web.1]: ^
2021-01-11T22:10:14.285454+00:00 app[web.1]: 
2021-01-11T22:10:14.285454+00:00 app[web.1]: Error: Cannot find module 'dotenv'
2021-01-11T22:10:14.285454+00:00 app[web.1]: Require stack:
2021-01-11T22:10:14.285455+00:00 app[web.1]: - /app/app.js
2021-01-11T22:10:14.285455+00:00 app[web.1]: - /app/bin/www
2021-01-11T22:10:14.285456+00:00 app[web.1]: at Function.Module._resolveFilename (internal/modules/cjs/loader.js:815:15)
2021-01-11T22:10:14.285456+00:00 app[web.1]: at Function.Module._load (internal/modules/cjs/loader.js:667:27)
2021-01-11T22:10:14.285457+00:00 app[web.1]: at Module.require (internal/modules/cjs/loader.js:887:19)
2021-01-11T22:10:14.285457+00:00 app[web.1]: at require (internal/modules/cjs/helpers.js:74:18)
2021-01-11T22:10:14.285458+00:00 app[web.1]: at Object.<anonymous> (/app/app.js:1:1)
2021-01-11T22:10:14.285458+00:00 app[web.1]: at Module._compile (internal/modules/cjs/loader.js:999:30)
2021-01-11T22:10:14.285459+00:00 app[web.1]: at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)
2021-01-11T22:10:14.285459+00:00 app[web.1]: at Module.load (internal/modules/cjs/loader.js:863:32)
2021-01-11T22:10:14.285459+00:00 app[web.1]: at Function.Module._load (internal/modules/cjs/loader.js:708:14)
2021-01-11T22:10:14.285460+00:00 app[web.1]: at Module.require (internal/modules/cjs/loader.js:887:19) {
2021-01-11T22:10:14.285460+00:00 app[web.1]: code: 'MODULE_NOT_FOUND',
2021-01-11T22:10:14.285461+00:00 app[web.1]: requireStack: [ '/app/app.js', '/app/bin/www' ]
2021-01-11T22:10:14.285461+00:00 app[web.1]: }
2021-01-11T22:10:14.301983+00:00 app[web.1]: npm ERR! code ELIFECYCLE
2021-01-11T22:10:14.302357+00:00 app[web.1]: npm ERR! errno 1
2021-01-11T22:10:14.309690+00:00 app[web.1]: npm ERR! finale-backend@0.0.0 start: `node ./bin/www`
2021-01-11T22:10:14.309804+00:00 app[web.1]: npm ERR! Exit status 1
2021-01-11T22:10:14.309965+00:00 app[web.1]: npm ERR!
2021-01-11T22:10:14.310034+00:00 app[web.1]: npm ERR! Failed at the finale-backend@0.0.0 start script.
2021-01-11T22:10:14.310119+00:00 app[web.1]: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
2021-01-11T22:10:14.317026+00:00 app[web.1]: 
2021-01-11T22:10:14.317243+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2021-01-11T22:10:14.317339+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2021-01-11T22_10_14_310Z-debug.log
2021-01-11T22:10:14.361923+00:00 heroku[web.1]: Process exited with status 1
2021-01-11T22:10:14.435764+00:00 heroku[web.1]: State changed from starting to crashed
2021-01-11T22:10:14.439118+00:00 heroku[web.1]: State changed from crashed to starting
2021-01-11T22:10:16.805923+00:00 heroku[web.1]: Starting process with command `npm start`
2021-01-11T22:10:19.751944+00:00 app[web.1]: 
2021-01-11T22:10:19.751961+00:00 app[web.1]: > finale-backend@0.0.0 start /app
2021-01-11T22:10:19.751962+00:00 app[web.1]: > node ./bin/www
2021-01-11T22:10:19.751963+00:00 app[web.1]: 
2021-01-11T22:10:19.808881+00:00 app[web.1]: internal/modules/cjs/loader.js:818
2021-01-11T22:10:19.808883+00:00 app[web.1]: throw err;
2021-01-11T22:10:19.808883+00:00 app[web.1]: ^
2021-01-11T22:10:19.808883+00:00 app[web.1]: 
2021-01-11T22:10:19.808884+00:00 app[web.1]: Error: Cannot find module 'dotenv'
2021-01-11T22:10:19.808884+00:00 app[web.1]: Require stack:
2021-01-11T22:10:19.808884+00:00 app[web.1]: - /app/app.js
2021-01-11T22:10:19.808885+00:00 app[web.1]: - /app/bin/www
2021-01-11T22:10:19.808885+00:00 app[web.1]: at Function.Module._resolveFilename (internal/modules/cjs/loader.js:815:15)
2021-01-11T22:10:19.808885+00:00 app[web.1]: at Function.Module._load (internal/modules/cjs/loader.js:667:27)
2021-01-11T22:10:19.808886+00:00 app[web.1]: at Module.require (internal/modules/cjs/loader.js:887:19)
2021-01-11T22:10:19.808886+00:00 app[web.1]: at require (internal/modules/cjs/helpers.js:74:18)
2021-01-11T22:10:19.808887+00:00 app[web.1]: at Object.<anonymous> (/app/app.js:1:1)
2021-01-11T22:10:19.808887+00:00 app[web.1]: at Module._compile (internal/modules/cjs/loader.js:999:30)
2021-01-11T22:10:19.808887+00:00 app[web.1]: at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)
2021-01-11T22:10:19.808888+00:00 app[web.1]: at Module.load (internal/modules/cjs/loader.js:863:32)
2021-01-11T22:10:19.808888+00:00 app[web.1]: at Function.Module._load (internal/modules/cjs/loader.js:708:14)
2021-01-11T22:10:19.808889+00:00 app[web.1]: at Module.require (internal/modules/cjs/loader.js:887:19) {
2021-01-11T22:10:19.808889+00:00 app[web.1]: code: 'MODULE_NOT_FOUND',
2021-01-11T22:10:19.808889+00:00 app[web.1]: requireStack: [ '/app/app.js', '/app/bin/www' ]
2021-01-11T22:10:19.808890+00:00 app[web.1]: }
2021-01-11T22:10:19.834122+00:00 app[web.1]: npm ERR! code ELIFECYCLE
2021-01-11T22:10:19.834754+00:00 app[web.1]: npm ERR! errno 1
2021-01-11T22:10:19.843644+00:00 app[web.1]: npm ERR! finale-backend@0.0.0 start: `node ./bin/www`
2021-01-11T22:10:19.843996+00:00 app[web.1]: npm ERR! Exit status 1
2021-01-11T22:10:19.844353+00:00 app[web.1]: npm ERR!
2021-01-11T22:10:19.844619+00:00 app[web.1]: npm ERR! Failed at the finale-backend@0.0.0 start script.
2021-01-11T22:10:19.844914+00:00 app[web.1]: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
2021-01-11T22:10:19.858827+00:00 app[web.1]: 
2021-01-11T22:10:19.859298+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2021-01-11T22:10:19.859536+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2021-01-11T22_10_19_845Z-debug.log
2021-01-11T22:10:19.946324+00:00 heroku[web.1]: Process exited with status 1
2021-01-11T22:10:20.030800+00:00 heroku[web.1]: State changed from starting to crashed
2021-01-11T22:10:22.579029+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=XXXXXX.herokuapp.com request_id=28ed0f16-48b7-4edb-a4d4-bf5af57518a5 fwd="91.106.154.160" dyno= connect= service= status=503 bytes= protocol=https
2021-01-11T22:10:23.309377+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=XXXXXX.herokuapp.com request_id=967010fc-984e-49c7-a73e-9d9758907f49 fwd="91.106.154.160" dyno= connect= service= status=503 bytes= protocol=https

我的包 json 看起来像这样：

{
  "name": "finale-backend",
  "version": "0.0.0",
  "private": true,
  "scripts": {
    "start": "node ./bin/www",
    "dev": "nodemon ./bin/www"
  },
  "dependencies": {
    "bcrypt": "^5.0.0",
    "body-parser": "^1.19.0",
    "cookie-parser": "~1.4.4",
    "cors": "^2.8.5",
    "debug": "~2.6.9",
    "express": "~4.16.1",
    "helmet": "^4.3.1",
    "jsonwebtoken": "^8.5.1",
    "logger": "0.0.1",
    "morgan": "~1.9.1",
    "nodemon": "^2.0.7",
    "pg": "^8.5.1"
  },
  "devDependencies": {
    "dotenv": "^8.2.0"
  },
  "engines": {
    "node": "12.x"
  }
}

我在入口点 app.js 中需要 dotenv，就像这样

require('dotenv').config();
const express = require('express');
const path = require('path');
const cookieParser = require('cookie-parser');
const logger = require('morgan');
const cors = require('cors')

【问题讨论】：

标签： node.js heroku deployment errno dotenv

【解决方案1】：

Heroku 似乎没有默认安装 devDependencies。您可能希望将 dotenv 移至 package.json 中的依赖项，然后重试。

如果您的生产环境中不需要 dotenv，您可能希望完全删除 require 并使用不同的命令来运行您的开发服务器，如下所述：

https://www.npmjs.com/package/dotenv#preload

node -r dotenv/config your_script.js

这将防止您的服务器在 Heroku 上找不到 dotenv 依赖项时在生产中崩溃。

【讨论】：

非常感谢拉尔夫！它像魔术一样工作。 :D

【解决方案2】：

原因是因为您在 devDependencies 中使用了 dotenv。将 dotenv 依赖项更改为这样的依赖项：

 "dependencies": {
...,
"dotenv": "^8.2.0"
  }

【讨论】：