Merge ~afreiberger/charm-grafana/+git/grafana-charm:anymetricdashboards into ~prometheus-charmers/charm-grafana:master

[Drew Freiberger]

Update dashboard generation to allow for 50% or more matching metrics to enable dashboard

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[Chris Sanders (chris.sanders)]

I like the list comprehension it's a lot easier to understand than the break/else. We should rework that without the % comparison and instead fix the dashboards to not have missing metrics.

review: Disapprove

Unmerged commits

e42cf7b... by Drew Freiberger on 2018-08-23

Update dashboard generation to allow for 50% or more matching metrics to enable dashboard

diff --git a/reactive/grafana.py b/reactive/grafana.py
index add41be..370686d 100644
--- a/reactive/grafana.py
+++ b/reactive/grafana.py
@@ -44,6 +44,7 @@ GRAFANA_INI_TMPL = 'grafana.ini.j2'
 GRAFANA_DEPS = ['libfontconfig1']
 DASHBOARDS_BACKUP_CRON = '/etc/cron.d/juju-dashboards-backup'
 DASHBOARDS_BACKUP_CRON_TMPL = 'juju-dashboards-backup.j2'
+MIN_MATCHING_METRICS_FOR_DASH_PCT = 50
 
 
 try:
@@ -518,13 +519,15 @@ def generate_prometheus_dashboards(gf_adminpasswd, ds):
             expr = str(re.findall('"expr":(.*),', template.read()))
             metrics = re.findall('[a-zA-Z0-9]*_[a-zA-Z0-9_]*', expr)
             if not metrics:
-                hookenv.log("Skipping Dashboard Template: {} no metrics"
+                hookenv.log("Skipping Dashboard Template: {} no metrics in template"
                             " {}".format(filename, metrics))
                 continue
-            for metric in metrics:
-                if metric not in prom_metrics:
-                    hookenv.log("Skipping Dashboard Template: {} no metric"
-                                " {}".format(filename, metric))
+            matching_metrics = [x for x in metrics if x in prom_metrics]
+            missing_metrics = [x for x in metrics if x not in prom_metrics]
+            matching_pct = (len(matching_metrics) / len(metrics)) * 100
+            if matching_pct < MIN_MATCHING_METRICS_FOR_DASH_PCT:
+                    hookenv.log("Skipping Dashboard Template: {} missing metrics for"
+                                " {}".format(filename, missing_metrics))
                     break
             else:
                 hookenv.log("Using Dashboard Template: {}".format(filename))