puppet: Extract zulip::analytics.

I'm not altogether happy with this (a better solution would be
database-level locking), but I think it solves the immediate problem
of folks with 2 servers being very likely to run analytics on both of
them.

puppet/zulip/manifests/analytics.pp

@@ -0,0 +1,11 @@
+# Default configuration for a Zulip app frontend
+class zulip::analytics {
+  # This should only be enabled on exactly 1 Zulip server in a cluster.
+  file { "/etc/cron.d/update-analytics-counts":
+    ensure => file,
+    owner  => "root",
+    group  => "root",
+    mode => 644,
+    source => "puppet:///modules/zulip/cron.d/update-analytics-counts",
+  }
+}

puppet/zulip/manifests/app_frontend.pp

@@ -1,6 +1,8 @@
 # Default configuration for a Zulip app frontend
 class zulip::app_frontend {
   include zulip::app_frontend_base
+  # For a single-server setup, run analytics on that server
+  include zulip::analytics
 
   file { "/etc/nginx/sites-available/zulip-enterprise":
     require => Package["nginx-full"],
@@ -42,12 +44,4 @@
     mode => 644,
     source => "puppet:///modules/zulip/cron.d/restart-zulip",
   }
-  # This should only be enabled on exactly 1 Zulip server in a cluster.
-  file { "/etc/cron.d/update-analytics-counts":
-    ensure => file,
-    owner  => "root",
-    group  => "root",
-    mode => 644,
-    source => "puppet:///modules/zulip/cron.d/update-analytics-counts",
-  }
 }

puppet/zulip_ops/manifests/prod_app_frontend.pp

@@ -1,6 +1,7 @@
 class zulip_ops::prod_app_frontend {
   include zulip_ops::base
   include zulip_ops::app_frontend
+  include zulip::analytics
 
   file { "/etc/nginx/sites-available/zulip":
     require => Package["nginx-full"],