prometheus: Move weblate metrics to pushgateway.

We leave the weblate metrics server and add a cron job to fetch its
contents and post them to the pushgateway.

puppet/kandra/manifests/prometheus/weblate.pp

@@ -17,7 +17,6 @@ class kandra::prometheus::weblate {
     source => 'puppet:///modules/kandra/weblate_exporter',
   }
 
-  kandra::firewall_allow { 'weblate_exporter': port => '9189' }
   file { "${zulip::common::supervisor_conf_dir}/weblate_exporter.conf":
     ensure  => file,
     require => [
@@ -31,4 +30,11 @@ class kandra::prometheus::weblate {
     content => template('kandra/supervisor/conf.d/weblate_exporter.conf.template.erb'),
     notify  => Service[supervisor],
   }
+
+  include kandra::prometheus::pushgateway
+  zulip::cron { 'weblate-to-pushgateway':
+    minute    => '*/15',
+    command   => 'curl http://localhost:9189/metrics | curl --data-binary @- http://localhost:9091/metrics/job/weblate',
+    use_proxy => false,
+  }
 }

puppet/kandra/templates/prometheus/prometheus.yaml.template.erb

@@ -285,12 +285,6 @@ scrape_configs:
       - target_label: __address__
         replacement: localhost:9188
 
-  - job_name: "weblate"
-    scrape_interval: 15m
-    scrape_timeout: 120s
-    static_configs:
-      - targets: ["localhost:9189"]
-
   - job_name: "vector"
     scrape_interval: 30s
     scrape_timeout: 3s