[nodejs] allow mounting local dd-trace-js as weblog volume

[rochdev]

Motivation

Right now we have to npm pack the local code, copy the resulting archive to system-tests/binaries, and rebuild weblog for every single code change before we can rerun the tests.

By allowing to instead mount the local dd-trace-js folder as a volume on the container, we can simply rerun the tests on code changes without having to go through any of the above.

Changes

Allow mounting local dd-trace-js as weblog volume.

Workflow

1. ⚠️ Create your PR as draft ⚠️
2. Work on you PR until the CI passes (if something not related to your task is failing, you can ignore it)
3. Mark it as ready for review
   • Test logic is modified? -> Get a review from RFC owner. We're working on refining the codeowners file quickly.
   • Framework is modified, or non obvious usage of it -> get a review from R&P team

🚀 Once your PR is reviewed, you can merge it!

🛟 #apm-shared-testing 🛟

Reviewer checklist

• If PR title starts with [<language>], double-check that only <language> is impacted by the change
• No system-tests internal is modified. Otherwise, I have the approval from R&P team
• CI is green, or failing jobs are not related to this change (and you are 100% sure about this statement)
• A docker base image is modified?
  • the relevant build-XXX-image label is present
• A scenario is added (or removed)?
  • Get a review from R&P team

[robertomonteromiguel]

I like the idea of assembling the volumes, but I also wonder how much we gain. I mean looking for the balance of keeping the code easy to read, its complexity and homogeneity (we run apps in different languages).

[rochdev]

I like the idea of assembling the volumes, but I also wonder how much we gain. I mean looking for the balance of keeping the code easy to read, its complexity and homogeneity (we run apps in different languages).

This is by far the biggest pain point of working with system tests (except for them being slow), so I'd say it's warranted especially since it doesn't really increase complexity all that much. As for homogeneity, I would agree but only in the sense that this should also be done for other languages if possible, although this is out of scope of this first PR.

I addressed his comments and he just went on vacation for a month

[cbeauchesne]

I addressed his comments and he just went on vacation for a month

Don't worry, he just sent me all his pending reviews.

[rochdev]

It looks like the CI failure is also happening on other branches and so it's unrelated to this PR.

[simon-id]

Don't know much about the python internals but otherwise LGTM

[rochdev]

@cbeauchesne PR is ready for one last look!

[cbeauchesne]

All good, thank you for tackling this.