Now it is able to install proemtheus on host and
use it to scrape data from other prometheuses.
Prod-related: PROD-17350
Change-Id: I11d65920c0e9b685dead22a5551521fa15d13f25
New version changes:
* different alerts format
* rewritten storage (some config flags removed)
Closes-Bug: PROD-16609
Change-Id: I805fa322e4744e98177d6c3e29589ebc6fb917a2
For some alerts we use reclass to get variables
(ex. threshold). To get those reclass variables
we use `prometheus_server` dict, which on nodes
without prometheus class is None.
We need to provide at least empty dict in that
case.
Change-Id: Ic1f2c1776c4852701dcf9f8a76f933926b2d9aec