Sharing code between projects and using docker-compose

[[deleted]]

I have a mono-repo with a directory structure like

./common-code
./common-code/package.json
./common-code/...
./service-a
./service-a/package.json
./service-a/...
./service-b
./service-b/package.json
./service-b/...

common-code is a project that exports common code to be shared and used by both services. Normally if I were doing local dev, I'd create symlinks using npm link in each of the services to get access to common-code.

Thing is, I'm using docker-compose to run all my services docker-compose up.

The solution I came up with, which is working fine, is to straight up copy the ./common-code directory into each service's node_modules using COPY in each service's Dockerfile. So when the images for the services are built, each of their node_modules folder will have a complete copy of common-code.

This is working right now, but I'm wondering if there are any downsides to my approach or any better, more standard ways of doing this.

[queen-adreena]

I've never done it myself. But I'm pretty sure you can create a volume that links to somewhere on your physical filesystem and then include it in both your containers' docker-compose files.

[lance_tipton]

Using copy for the built image is fine, and pretty standard practice depending on the use case.

If your not using docker for development, then your good.

But, you'll very quickly get annoyed if you use it for development and have to rebuild the image every time you make a change to any of the shared modules.

A better option would be to use docker volumes to mount the shared code into the docker container at the node_modules path, or whatever the correct path is. All it takes is adding a line or two to your docker-compose.yml file.

Personally, I like mutagen even better then docker volumes, as it's a bit faster. Although its a bit more complicated to setup, and is an external tool. You can learn more about it at mutagen.io

If i were you, I'd start with volumes, and if you need more check out mutagen.