Merge ~ballot/content-cache-charm/+git/content-cache-charm:add_relations into content-cache-charm:master

[Benjamin Allot]

Unmerged commits

4a57101... by Benjamin Allot on 2019-10-02

Add an endpoint exposing the url for nginx metrics.

diff --git a/layer.yaml b/layer.yaml
index 6a7e8dc..bb61bd1 100644
--- a/layer.yaml
+++ b/layer.yaml
@@ -2,6 +2,7 @@ includes:
   - layer:basic
   - layer:nagios
   - layer:status
+  - interface:input-prometheus
 repo: lp:content-cache-charm
 options:
   basic:
diff --git a/metadata.yaml b/metadata.yaml
index a3b5a01..ca7a3c8 100644
--- a/metadata.yaml
+++ b/metadata.yaml
@@ -20,3 +20,6 @@ provides:
   haproxy-statistics:
     interface: statistics
     scope: container
+  nginx-prometheus-exporter:
+    interface: input-prometheus
+    scope: container
diff --git a/reactive/content_cache.py b/reactive/content_cache.py
index e40c284..24b70c4 100644
--- a/reactive/content_cache.py
+++ b/reactive/content_cache.py
@@ -382,6 +382,16 @@ def advertise_stats_endpoint():
         rel.local['password'] = password
 
 
[e-mail]('content_cache.nginx.configured')
[e-mail]('input-prometheus.available')
+def advertise_input_prometheus_urls():
+    rels = context.Relations()
+
+    for rel in rels['input-prometheus'].values():
+        rel.local['private-address'] = hookenv.unit_private_ip()
+        rel.local['port'] = nginx.METRICS_PORT
+
+
 @reactive.when('haproxy-statistics.available')
 @reactive.when('nrpe-external-master.available')
 @reactive.when_not('nagios-nrpe-telegraf.configured')