headlamp-plugin: Make the package arg of the build command optional

[joaquimrocha]

We rely on just calling the "headlamp-plugin build" command without
any arguments, but the build command expected a positional argument as
required, so the default and advised case for building plugins was
failing.

[illume]

interestingly, the CI found a bug when using npm 7. Where npm 7 gets into a loop resolving dependencies, and keeps processing until it runs out of memory. See npm/cli#3359 and npm/cli#3208

There's a work around for running it on CI with npm 7, but users of npm 7 will encounter this bug.

I tried updating the plugin dependencies, and still get the issue. There's another work around or two to try(which I will do next)... but ultimately the bug in npm 7 needs fixing (or maybe it's a bug in one of the dependencies).

[illume]

Adding a package-lock.json generated with npm v6 to the template lets npm v7 work.

[illume]

👍 🎉

[illume]

Probably we should release a new @kinvolk/headlamp-plugin version.

[joaquimrocha]

@illume , It all LGTM. The only thing I noticed is that we're not testing the headlamp-plugin build (no argument) which is what failed initially, or maybe I missed it?

[illume]

@joaquimrocha yeah. It's not directly calling headlamp-plugin build... but it does so through npm run build which calls that. I'll update the test to call headlamp-plugin build with no argument directly.

[illume]

The headlamp-plugin build is tested better now, and also added a test for headlamp-plugin extract.

[joaquimrocha]

Thanks!