Add alert from the cortex mixin. (#275)

* Add alert from the cortex mixin.

Signed-off-by: Tom Wilkie <[email protected]>

* lint

Signed-off-by: Tom Wilkie <[email protected]>

Author: tomwilkie

memcached-mixin/alerts.libsonnet

@@ -0,0 +1,26 @@
+{
+  prometheusAlerts+: {
+    groups+: [
+      {
+        name: 'memcached',
+        rules: [
+          {
+            alert: 'MemcachedDown',
+            expr: |||
+              memcached_up == 0
+            |||,
+            'for': '15m',
+            labels: {
+              severity: 'critical',
+            },
+            annotations: {
+              message: |||
+                Memcached Instance {{ $labels.job }} / {{ $labels.instance }} is down for more than 15mins.
+              |||,
+            },
+          },
+        ],
+      },
+    ],
+  },
+}

memcached-mixin/mixin.libsonnet

@@ -1,3 +1,5 @@
-(import 'dashboards.libsonnet') {
+(import 'dashboards.libsonnet') +
+(import 'alerts.libsonnet') +
+{
   grafanaDashboardFolder: 'Memcached',
 }