Set mysql max_connections to 1024 on nodepool

Nodepool can end up with one connection per thread when dealing
with launches and deletions.  If we have a lot of node turnover,
that's a lot of threads.

Change-Id: Ice483f5f9f3a47963357f9ff59bf4d735a18aa43

modules/nodepool/manifests/init.pp

@@ -49,6 +49,14 @@ class nodepool (
     ],
   }
 
+  file { '/etc/mysql/conf.d/max_connections.cnf':
+    ensure  => present,
+    content => "[server]\nmax_connections = 1024\n",
+    mode    => '0444',
+    owner   => 'root',
+    group   => 'root',
+  }
+
   user { 'nodepool':
     ensure     => present,
     home       => '/home/nodepool',