NPM 模块在 /node_modules 文件夹中但找不到？

Question

I am having a bit of an issue getting the md5 node module installed properly on an Ubuntu dev server I have setup.

(It works fine on my local windows machine, and I can install other modules with npm just fine on the dev server)

When I try and start a NodeJS application I am working on it fails stating that the md5 module is not installed.

    // trying to start my application that depends on md5.
    drichardson@devwebserver:/var/www/node_app/meanapp$ node server.js
    module.js:340
        throw err;
        ^
    Error: Cannot find module 'md5'
        at Function.Module._resolveFilename (module.js:338:15)
        at Function.Module._load (module.js:280:25)
        at Module.require (module.js:364:17)
        at require (module.js:380:17)
        at Object.<anonymous> (/var/www/node_app/node_modules/hashfile/index.js:7:11)
        at Module._compile (module.js:456:26)
        at Object.Module._extensions..js (module.js:474:10)
        at Module.load (module.js:356:32)
        at Function.Module._load (module.js:312:12)
        at Module.require (module.js:364:17)
        at require (module.js:380:17)
        at Object.<anonymous> (/var/www/node_app/meanapp/app/controllers/exchanges.server.controller.js:15:14)
        at Module._compile (module.js:456:26)
        at Object.Module._extensions..js (module.js:474:10)
        at Module.load (module.js:356:32)
        at Function.Module._load (module.js:312:12)

I have tried installing this within my working directory:

    // Installing in working directory
    drichardson@devwebserver:/var/www/node_app/meanapp$ sudo npm install --save md5
    npm http GET https://registry.npmjs.org/md5
    npm http GET https://registry.npmjs.org/md5
    npm http 304 https://registry.npmjs.org/md5
    npm http GET https://registry.npmjs.org/is-buffer
    npm http GET https://registry.npmjs.org/crypt
    npm http GET https://registry.npmjs.org/charenc
    npm http 304 https://registry.npmjs.org/crypt
    npm http GET https://registry.npmjs.org/is-buffer
    npm http GET https://registry.npmjs.org/charenc
    npm http 200 https://registry.npmjs.org/is-buffer
    npm http GET https://registry.npmjs.org/is-buffer/-/is-buffer-1.0.2.tgz
    npm http GET https://registry.npmjs.org/is-buffer/-/is-buffer-1.0.2.tgz
    npm http GET https://registry.npmjs.org/charenc
    npm http GET https://registry.npmjs.org/charenc/-/charenc-0.0.1.tgz
    npm http 200 https://registry.npmjs.org/charenc/-/charenc-0.0.1.tgz
    npm http GET https://registry.npmjs.org/is-buffer/-/is-buffer-1.0.2.tgz
    npm http 200 https://registry.npmjs.org/is-buffer/-/is-buffer-1.0.2.tgz
    md5@2.0.0 node_modules/md5
    ├── charenc@0.0.1
    ├── crypt@0.0.1
    └── is-buffer@1.0.2

Even though the node module shows up in my /node_modules folder, it still throws the "Cannot find module md5 "

    // MD5 In my node_modules folder:
    drichardson@devwebserver:/var/www/node_app/meanapp/node_modules$ ls -la | grep 'md5'
    drwxr-xr-x  2 drichardson drichardson 4096 Oct 30 13:53 md5

I have also tried:

- Installing the module globally with "npm install -g md5"
- Cleaning the Cache and Reinstalling "npm cache clean"
- Reinstalling the application with "npm install"

What else can I try to get this so that npm recognizes md5 as being installed?

Thanks,

Answer 1

I had a similar issue and the problem wasn't where the module was installed, but instead it was because the main property in the package.json file was not correctly set. In my case it referred to a file that wasn't there. Make sure that the "main":"..." is set correctly for the module.

If this is a module that you do not control, as a quick fix you can make the change in the nearest node_modules directory. In our case this was located in the root of the project.

Answer 2

Can you try clearing entire node_modules and installing everything again?

   rm -rf node_modules
   npm install

Answer 3

In folder /var/www/node_app/node_modules/hashfile/

run npm install md5

You tried this?

Answer 4

My problem ended up being the version of Node and NPM that I was running locally vs in my Docker containers.

# Local versions:
$ node --version
v12.18.2
$ npm --version
6.14.10

I changed in my Dockerfile

FROM node:15-alpine3.12
#         ^^
# ...

to

FROM node:12-alpine3.12
#         ^^
# ...