Nodemon is not working in Docker environment

Question

I'm using Docker with fig to build NodeJS dev-env.

While I using nodemon to watch the server.js, changing server.js won't restart the server.

CMD ["nodemon", "/nodeapp/server.js"]

But while I changed from nodemon to supervisor, then it worked!

CMD ["supervisor", "/nodeapp/server.js"]

Does anyone know where the problem is?

More informations are below:

My fig folder structure:

app/server.js
    package.json
    node_modules/
fig.yml
Dockerfile

fig.yml:

nodejs:
  build: .
  ports:
    - "8080:8080"

Dockerfile:

RUN apt-get update --fix-missing
RUN rm /bin/sh && ln -s /bin/bash /bin/sh

# NVM
RUN curl -sL https://deb.nodesource.com/setup | sudo bash - && \
  apt-get install -y nodejs

VOLUME ./app:/nodeapp
WORKDIR /nodeapp

RUN rm /bin/sh && ln -s /bin/bash /bin/sh && \
  npm install -g nodemon mocha supervisor
CMD ["nodemon", "/nodeapp/server.js"]

Server.js: (sample code from NodeJS website)

var http = require('http');

http.createServer(function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end('Hello 12\n');
}).listen(8080);

console.log('Server running at http://127.0.0.1:8080/');

score 30 · Answer 1 · edited Jul 30 '20 at 07:25

30

There is a special option to enable nodemon's legacy watching mode:

nodemon --legacy-watch

edited Jul 30 '20 at 07:25

Jonathan Holvey

467
5
17

answered Dec 14 '18 at 08:31

haiflive

917
10
12

2

This is apparently the recommended way to get nodemon working inside a Docker container https://github.com/remy/nodemon#application-isnt-restarting – Jonathan Holvey Jul 30 '20 at 02:42
`-L` shorthand, but this also worked for me – Jeremy Hamm Mar 04 '21 at 06:10

Jan · Answer 2 · 2014-12-12T12:16:23.553

This is how I do it:

You will need nodemon version 1.3.0-5 for this (npm i -g nodemon@dev)

.dockerignore:

node_modules/*

Dockerfile:

FROM node:0.10

WORKDIR /nodeapp
ADD ./package.json /nodeapp/package.json
RUN npm install --production

ADD ./app /nodeapp/app

EXPOSE 8080

CMD ["node", ".", "--production"]

package.json:

{
  "name": "fig-nodemon",
  "version": "1.0.0",
  "description": "",
  "main": "./app/server.js",
  "scripts": {
    "nodemon": "fig up -d && fig run nodejs npm i --development && nodemon -x \"fig kill nodejs && fig build nodejs && fig start nodejs && fig logs nodejs\""
  },
  "author": "",
  "license": "MIT"
}

fig.yml:

nodejs:
  build: .
  command: node . --development
  volumes:
    - ./app:/nodeapp/app
  ports:
    - "8080:8080"

app/server.js:

var http = require('http');

http.createServer(function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end('Hello 13\n');
}).listen(8080);

console.log('Server running at http://127.0.0.1:8080/');

then I run npm run nodemon to get started.

score 3 · Accepted Answer · answered Dec 02 '14 at 02:29

first up - VOLUME ./app:/nodeapp does not do what you want - you're creating a directory in the image called /app:/nodeapp - and so at no point is the server.js file getting onto your image.

test using docker run --rm -it yourimagename ls -la

changing your Dockerfile to

FROM ubuntu

RUN apt-get update --fix-missing
RUN apt-get install -yq curl
RUN rm /bin/sh && ln -s /bin/bash /bin/sh

# NVM
RUN curl -sL https://deb.nodesource.com/setup | sudo bash - && \
  apt-get install -y nodejs

#VOLUME ./app:/nodeapp
ADD     app /nodeapp
WORKDIR /nodeapp

RUN rm /bin/sh && ln -s /bin/bash /bin/sh && \
  npm install -g nodemon mocha supervisor
CMD ["nodemon", "/nodeapp/server.js"]

gets me:

mini:nodaemon sven$ docker run --rm -it -p 8080:8080 nodaemon     
2 Dec 02:27:52 - [nodemon] v1.2.1
2 Dec 02:27:52 - [nodemon] to restart at any time, enter `rs`
2 Dec 02:27:52 - [nodemon] watching: *.*
2 Dec 02:27:52 - [nodemon] starting `node /nodeapp/server.js`
Server running at http://127.0.0.1:8080/

Thanks for your reply. There's a mistake in my Dockerfile. Actually, what I want is: My nodejs env is in the Docker container. While I change my code in the project folder on my host OS, the container will detect the changed file and then restart the server.js automatically. It's my mistake that I didn't describe my problem well. Can Docker do that? — kerkerj, Dec 04 '14 at 07:45

score -1 · Answer 4 · answered Oct 29 '19 at 11:39

Assuming you've the project running using a nodemon and struggling with docker-izing it.

Make sure the terminal points inside the project's root folder.

Step 1 : Build docker image

docker build -t docker-image-name .

Step 2: Run image with a volume mount

docker run -it -p 9000:3000 -v $(pwd):/app docker-image-name

Nodemon is not working in Docker environment

4 Answers4