(FACT-1557) Extend the cloud.provider fact to Google Compute Engine

[natemccurdy]

Similar to #2475 , this allows the cloud.provider fact to resolve on Google Compute Engine nodes to gce.

For example:

[user@a_gce_node]> facter cloud.provider
gce

This partially resolves https://tickets.puppetlabs.com/browse/FACT-1557

Note that I chose to have this resolve to the string "gce" because that's what the current virtual fact resolves to, so Facter/Puppet users are probably most familiar with "gce" meaning Google Compute Engine.

[puppetlabs-jenkins]

Can one of the admins verify this patch?

[joshcooper]

@natemccurdy could you prepend (FACT-1557) to your commit summary and force push to your feature branch?

[natemccurdy]

could you prepend (FACT-1557) to your commit summary and force push to your feature branch?

@joshcooper Done. Thanks for looking!

[natemccurdy]

Offering given to the Rubocop gods, tests updated for lint failures, and branch force pushed. The rubocop tests should pass now.

[natemccurdy]

Guess I didn't make the right offering, sorry RuboCop gods.
This time I fixed the lint issue, and verified locally with:

~/src/puppetlabs/facter [FACT-1557/cloud_provider_gce] be rubocop --parallel
Inspecting 1730 files
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1730 files inspected, no offenses detected

[natemccurdy]

@joshcooper What do you recommend I do about the new RuboCop warnings?

New offenses:
  - lib/facter/facts/linux/cloud/provider.rb:
    - Metrics/CyclomaticComplexity: changed from 0 to 1
  - lib/facter/facts/windows/cloud/provider.rb:
    - Metrics/CyclomaticComplexity: changed from 0 to 1

[joshcooper]

@natemccurdy could you add exclusions for those files to .rubocop.yml and add that as a second commit? If the rubocop checks are performed for each commit, you may need to switch the order so the files are excluded first?

[natemccurdy]

...add exclusions for those files to .rubocop.yml

Done 👍

[joshcooper]

Verified this behaves as expected on GCE:

~/facter# bundle exec facter cloud.provider
gce

and it has parity with other cloud providers facts like https://tickets.puppetlabs.com/browse/FACT-1441