CODEWITHSUNDEEP
docker
yoursweater
yoursweater

Reputation: 2041

Docker app with json-server can't find the npm module

I have an extremely simple Docker app that uses json-server as a fake backend, but I can't get it to work for some bizarre reason. Here's the Docker file:

The directory I'm building this in contains a Dockerfile, server.js, and db.json.

FROM node:latest
RUN npm install json-server -g
WORKDIR /app
ADD . /app
EXPOSE 3004
CMD ["node", "server.js"]

The json-server itself is dead simple:

const jsonServer = require('json-server')
const server = jsonServer.create()
const router = jsonServer.router('db.json')
const middlewares = jsonServer.defaults()

server.use(middlewares)
server.use(router)
server.listen(3004, () => {
  console.log('JSON Server is running')
})

Docker is able to build this image. But when I try to run it, I get the following error:

node:internal/modules/cjs/loader:1042
  throw err;
  ^

Error: Cannot find module 'json-server'
Require stack:
- /app/server.js
    at Module._resolveFilename (node:internal/modules/cjs/loader:1039:15)
    at Module._load (node:internal/modules/cjs/loader:885:27)
    at Module.require (node:internal/modules/cjs/loader:1105:19)
    at require (node:internal/modules/cjs/helpers:103:18)
    at Object.<anonymous> (/app/server.js:1:20)
    at Module._compile (node:internal/modules/cjs/loader:1218:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1272:10)
    at Module.load (node:internal/modules/cjs/loader:1081:32)
    at Module._load (node:internal/modules/cjs/loader:922:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:82:12) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [ '/app/server.js' ]
}

Why can't it find the json-server module, especially when I just installed it globally? I'm so confused by this since it couldn't be simpler.

Upvotes: 2

Views: 743

Answers (2)

trepegorka
trepegorka

Reputation: 33

Using latest alpha version of json-server was not working for me as well.

Solution was downgrading version "json-server": "^0.17.0"

Upvotes: 3

Hans Kilian
Hans Kilian

Reputation: 25070

The node image doesn't set the NODE_PATH environment variable, so node can't find globally installed modules.

Since containers are only meant to run a single process, it doesn't really make sense to install things globally.

If you install the module non-globally in your /app directory, it works:

FROM node:latest
WORKDIR /app
RUN npm install json-server
ADD . /app
EXPOSE 3004
CMD ["node", "server.js"]

Upvotes: 1

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