Merge ~stub/prometheus-charm:setactive into prometheus-charm:master

[Stuart Bishop]

Set active workload state after reload

Active workload state was only being set after a restart, which
caused the unit to remain in maintenance states if only a reload
was needed to complete the operation. Addresses lp:1668142

The alternative would be a new set_active handler that kicks in when all relevant state is set/unset. Which works better in complex charms, but I don't think we are there yet.

[Jacek Nykis (jacekn)]

LGTM

review: Approve

diff --git a/reactive/prometheus.py b/reactive/prometheus.py
index 5cfbef6..d870d5d 100644
--- a/reactive/prometheus.py
+++ b/reactive/prometheus.py
@@ -386,6 +386,7 @@ def reload_prometheus():
         # Use SIGHUP to reload config gracefully
         subprocess.check_call(['killall', '-HUP', 'prometheus'])
         remove_state('prometheus.do-reload')
+        hookenv.status_set('active', 'Ready')
     else:
         # Let's make sure prometheus is up
         set_state('prometheus.do-restart')