Investigate gc metrics on alpine dists

[joao-fontenele]

maybe there's a problem with the lib prometheus-gc-stats that do not build on alpine dists.

I think I got an error for missing python on the container

[aledemajo]

I'm seeing a similar library problems problem when building express-prometheus-middleware as a Docker container using an apline distro. Here's some extra info for when you get around to this:

• I was able to replicate using node:14.15.4-alpine3.10 as the base image.

• I got a 403 while downloading gc-stats from AWS

node-pre-gyp WARN Tried to download(403): https://node-binaries.s3.amazonaws.com/gcstats/v1.4.0/Release/node-v83-linux-x64.tar.gz

• later in the installation process, this error:

gyp ERR! configure error
gyp ERR! stack Error: Could not find any Python installation to use

I'm assuming python comes with gcstats?

• However, I was still able to build the image and run it successfully without the dependencies:

npm WARN optional SKIPPING OPTIONAL DEPENDENCY: gc-stats@1.4.0 (node_modules/gc-stats):
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: gc-stats@1.4.0 install: `node-pre-gyp install --fallback-to-build`
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: Exit status 1