将 node.js 应用程序部署到 heroku 时出错找不到模块 dotenv，并且 npm ERR！errno 1

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该应用程序。这是部署的日志尾部。我不太确定问题出在哪里。使用邮递员测试时，所有本地主机路由实际上都在工作。我正在使用快速生成器，因此 PORT 在 .bin/www 中声明。我也在使用 .env。我有点不知道下一步该往哪里看。有什么建议么？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 如下所示：

{
  "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"
  }
}

而且我在我的入口点 app.js 中需要 dotenv 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') 

解决方法

Heroku 似乎默认没有安装 devDependencies。您可能希望将 dotenv 移动到 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

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