So I have this NodeJS express app. This is code works:

Dockerfile

FROM node:10.16-alpine

WORKDIR /app

COPY . /app

RUN npm install

CMD [npm, start]

docker-compose.yml

version: 3.7



services:

  node-express:

    build: .

    ports: 

      - 80:3000

But for this app I want to see the live code changes. So I know that
is where you can use Bind Mounts, but as soon as I add the volumes
like so:

docker-compose.yml

version: 3.7



services:

  node-express:

    build: .

    volumes: 

      - .:/app

    ports: 

      - 80:3000

It looks like the node_modules is not in the app directory anymore..
How can I fix this? I've worked on this for four hours, and I still
can't spot the mistake!

Error

HijackManiac:webserver hijackmaniac$ docker-compose up

Creating network webserver_default with the default driver

Building node-express

Step 1/5 : FROM node:10.16-alpine

 ---> a298c79121d9

Step 2/5 : WORKDIR /app

 ---> Running in 9b99df0f54ba

Removing intermediate container 9b99df0f54ba

 ---> 48f9b606b32d

Step 3/5 : COPY . /app

 ---> 1f29dc735dc7

Step 4/5 : RUN npm install

 ---> Running in 81225f56a9fd

npm WARN [email protected] No description

npm WARN [email protected] No repository field.



added 106 packages from 130 contributors and audited 202 packages in 3.344s

found 0 vulnerabilities



Removing intermediate container 81225f56a9fd

 ---> 2985dc77bc12

Step 5/5 : CMD [npm, start]

 ---> Running in 271ab42687ce

Removing intermediate container 271ab42687ce

 ---> 38a39768792e



Successfully built 38a39768792e

Successfully tagged webserver_node-express:latest

WARNING: Image for service node-express was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`.

Creating webserver_node-express_1 ... done

Attaching to webserver_node-express_1

node-express_1  | 

node-express_1  | > [email protected] start /app

node-express_1  | > node src/app.js

node-express_1  | 

node-express_1  | internal/modules/cjs/loader.js:638

node-express_1  |     throw err;

node-express_1  |     ^

node-express_1  | 

node-express_1  | Error: Cannot find module 'express'

node-express_1  |     at Function.Module._resolveFilename (internal/modules/cjs/loader.js:636:15)

node-express_1  |     at Function.Module._load (internal/modules/cjs/loader.js:562:25)

node-express_1  |     at Module.require (internal/modules/cjs/loader.js:690:17)

node-express_1  |     at require (internal/modules/cjs/helpers.js:25:18)

node-express_1  |     at Object.<anonymous> (/app/src/app.js:2:17)

node-express_1  |     at Module._compile (internal/modules/cjs/loader.js:776:30)

node-express_1  |     at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10)

node-express_1  |     at Module.load (internal/modules/cjs/loader.js:653:32)

node-express_1  |     at tryModuleLoad (internal/modules/cjs/loader.js:593:12)

node-express_1  |     at Function.Module._load (internal/modules/cjs/loader.js:585:3)

node-express_1  | npm ERR! code ELIFECYCLE

node-express_1  | npm ERR! errno 1

node-express_1  | npm ERR! [email protected] start: `node src/app.js`

node-express_1  | npm ERR! Exit status 1

node-express_1  | npm ERR! 

node-express_1  | npm ERR! Failed at the [email protected] start script.

node-express_1  | npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

node-express_1  | npm WARN Local package.json exists, but node_modules missing, did you mean to install?

node-express_1  | 

node-express_1  | npm ERR! A complete log of this run can be found in:

node-express_1  | npm ERR!     /root/.npm/_logs/2019-06-04T23_55_20_327Z-debug.log

webserver_node-express_1 exited with code 1

See working tree:

Before I added the volume in the docker-compose.yml, the container runs succesfully. This is the structure: