Supermon - Solving the infamous node_modules Docker problem

Node.js and Docker go together like peanut butter and jelly (if you are into such things). However, that combination has a common problem that everyone eventually has to face which is that the volume mapping from host also brings in node_modules/ that has code built specifically for the host OS. This can be solved with internal node_modules/ volume but now you are left with the problem of how do you sync any module installations done in the host machine to the internal volume within the container?

Supermon

Supermon is nodemon replacement that, while restarting your application on file changes it also monitors the package.json and makes sure that the modules that are mentioned there are installed to locally available node_modules/ directory.

In practice, this means that when you run npm install awsomemodule on your host machine, supermon running in a docker container will install the same module on the internal node_modules/ directory before restarting the application as usual. Such magic, much wow.

If you are running supermon normally, without any Docker shenanigans, it will do the usual application restart on file changes since the module installation is only triggered on the misalignment of package.json and node_modules/.

Also, it supports TypeScript out of the box via ts-node.

Install & usage

Install nodemon as usual

npm install supermon --save-dev

Add package.json script that runs supermon with the application entry file

{
  "scripts": {
    "dev": "supermon app.js"
  }
}

You can run the script in the container by overriding the command in docker-compose.yml

services:
  app:
    command: "npm run dev"

Feedback and bugs

I'm using supermon in my projects daily, however, it is still in its infancy and missing a lot of features so if you have any feedback or ideas, don't hesitate to create an issue

Happy coding!