feat(cloud monitoring): add support for cloud monitoring suppressions

[simonvetter]

This adds support for Cloud Monitoring suppressions.

It provides a couple of basic functions:

• getEntities to list all entities on your account,
• getEntityIdsByRegexp to get all the entity ids whose label matches a specific regexp (useful when entity labels are set to server hostnames and you want to get i.e. all your api servers or all your servers in a region)
• createEntitiesSuppression to create a suppression on an array of entity ids,
• deleteSuppression to delete a suppression.

[simonvetter]

in most cases, you would set up your dreadnot stacks so that the suppression is actually only created after both build and integration test phases have completed.

You'd think you should be able to set a suppression for 3+ hrs just to be safe, but in case your deploy fails, your DN stack won't execute entirely and you run the risk of leaving an active suppression on an entire DC behind. By making them expire after 30 mins, you make sure that even if you set a suppression that won't get deleted, it will still expire fairly shortly.

I guess the 30 min limit is rather arbitrary and depends on how long your deploy take, which is why you can always set an endTime of your choice from your DN stack (i.e. this is just a default used if you do not specify endTime, or an endTime of 0).

[rphillips]

+1

[ynachiket]

thanks for doing this .. the lights would be happy now :)