fix(monitoring): correct CoreDNS selector
diff --git a/atmosphere/jsonnet/rules.jsonnet b/atmosphere/jsonnet/rules.jsonnet
index 0589764..610332f 100644
--- a/atmosphere/jsonnet/rules.jsonnet
+++ b/atmosphere/jsonnet/rules.jsonnet
@@ -2,9 +2,14 @@
 
 local ceph = import 'ceph.libsonnet';
 local mysqld = import 'mysqld.libsonnet';
-local coredns = import 'vendor/coredns-mixin/mixin.libsonnet';
 local memcached = import 'vendor/memcached-mixin/mixin.libsonnet';
 
+local coredns = (import 'vendor/coredns-mixin/mixin.libsonnet') + {
+  _config+:: {
+    corednsSelector: 'job="coredns"',
+  },
+};
+
 {
   ceph: ceph.prometheusAlerts,
   coredns: coredns.prometheusAlerts,