Simple binary approach

[guybedford]

One of the major issues with binaries is that they are typically built for the target platform on install. This makes it very difficult to "statically" make binaries work for all platforms.

This PR brings back the google datastore test and gets it to pass by simply leaving the base-level binary package as an external of the build.

It may be possible to auto-detect binaries in this way (package.json with a binary field seems sufficient), and then inform users to keep them as dependencies so that this provides a fully automated binary workflow (combined with the corresponding node_modules location and build of the specific binary file on the target machine).

If the target architecture is known, then binary inlining could certainly be provided though. Most likely forking node-pre-gyp in such specific implementation work would be the best way to achieve this.

(note the reason this external approach works is because the previous asset relocation work overrides the webpack require to fall back to the build-time require).

[rauchg]

Very cool. I wonder if in this case we should also emit node_modules?

[rauchg]

CCing @TooTallNate who might have thoughts about this

[TooTallNate]

As far as node-gyp based dependencies goes, the presence of a binding.gyp file and a build dir in the dep signifies a native dependency.

I think when a native dep is encountered, we should find build/Release/*.node build/Release/*.so and copy those into <outdir>/build/. Native deps that rely on bindings module would then just work, and for the cases that directly require the .node file we can rewrite the location to reference the location relative to the outdir.

This would handle most cases I think. However I could imagine there being issues if there are conflicting binary artifacts in the outdir (for example, I know I name it binding.node in at least a few of my modules, as opposed to <modulename>.node which I think is more common).

[TooTallNate]

Is this PR actually related to binary support?

[guybedford]

It just gets a binary integration test to pass, but let's try and do better certainly. Happy to close this to tackle the more meaty approaches.

[Zertz]

FWIW, while there might be a better or more robust solution, getting "@google-cloud/datastore" to work would be a win 😃

[guybedford]

Note this is done with test options (setting grpc as an external) over being automatic or introducing code improvements. So it's really just adding a new unit integration test!

[Zertz]

Is it possible to set externals within a deployment on Now or otherwise get grpc to work while a full fix is developed?