P:wmcs::prometheus: fix openstack-exporter

The openstack exporter logic was relying on the fact that the openstack.
endpoint was hosted on a cloudcontrol host. We still want to scrape it
from a single cloudcontrol, so add a hiera variable to control which one
is used.

Bug: T346439
Change-Id: I6cd147e024ddb273eee18a64f2bf2cea9a51ebe0

hieradata/eqiad/profile/wmcs/prometheus.yaml

@@ -0,0 +1 @@
+profile::wmcs::prometheus::openstack_exporter_host: cloudcontrol1006.wikimedia.org

modules/profile/manifests/openstack/eqiad1/metrics.pp

@@ -1,18 +1,9 @@
 class profile::openstack::eqiad1::metrics (
-    Stdlib::Fqdn $controller = lookup('profile::openstack::eqiad1::keystone_api_fqdn'),
+    Stdlib::Fqdn $active_host = lookup('profile::wmcs::prometheus::openstack_exporter_host'),
 ) {
-    $this_ip = ipresolve($::fqdn, 4)
-    $controller_ip = ipresolve($controller, 4)
-
-    if $this_ip == $controller_ip {
-        class { '::profile::prometheus::openstack_exporter':
-            listen_port => 12345,
-            cloud       => 'eqiad1',
-        }
-        contain '::profile::prometheus::openstack_exporter'
-    } else {
-        class { '::profile::prometheus::openstack_exporter':
-            ensure => absent,
-        }
+    class { '::profile::prometheus::openstack_exporter':
+        ensure      => ($active_host == $::facts['networking']['fqdn']).bool2str('present', 'absent'),
+        listen_port => 12345,
+        cloud       => 'eqiad1',
     }
 }

modules/profile/manifests/wmcs/prometheus.pp

@@ -1,10 +1,11 @@
 class profile::wmcs::prometheus(
-    Stdlib::Unixpath $targets_path = '/srv/prometheus/labs/targets',
-    String $storage_retention = lookup('prometheus::server::storage_retention', {'default_value' => '4032h'}),
-    Integer $max_chunks_to_persist = lookup('prometheus::server::max_chunks_to_persist', {'default_value' => 524288}),
-    Integer $memory_chunks = lookup('prometheus::server::memory_chunks', {'default_value' => 1048576}),
-    Optional[Stdlib::Datasize] $storage_retention_size = lookup('profile::wmcs::prometheus::storage_retention_size',   {default_value => undef}),
-    Array[Stdlib::Host] $alertmanagers = lookup('alertmanagers', {'default_value' => []}),
+    Stdlib::Unixpath           $targets_path            = '/srv/prometheus/labs/targets',
+    String                     $storage_retention       = lookup('prometheus::server::storage_retention', {'default_value' => '4032h'}),
+    Integer                    $max_chunks_to_persist   = lookup('prometheus::server::max_chunks_to_persist', {'default_value' => 524288}),
+    Integer                    $memory_chunks           = lookup('prometheus::server::memory_chunks', {'default_value' => 1048576}),
+    Optional[Stdlib::Datasize] $storage_retention_size  = lookup('profile::wmcs::prometheus::storage_retention_size',   {default_value => undef}),
+    Stdlib::Fqdn               $openstack_exporter_host = lookup('profile::wmcs::prometheus::openstack_exporter_host'),
+    Array[Stdlib::Host]        $alertmanagers           = lookup('alertmanagers', {'default_value' => []}),
 ) {
     $config_extra = {
         'external_labels' => {
@@ -181,7 +182,7 @@
                 'site'    => 'eqiad',
             },
             'targets' => [
-                'openstack.eqiad1.wikimediacloud.org:12345',
+                "${openstack_exporter_host}:12345",
             ]
         }]),
     }