puppet: Factor out a sysctl operator.

puppet/zulip/manifests/app_frontend_base.pp

@@ -190,20 +190,9 @@ class zulip::app_frontend_base {
     content => template('zulip/uwsgi.ini.template.erb'),
     notify  => Service[$zulip::common::supervisor_service],
   }
-  file { '/etc/sysctl.d/40-uwsgi.conf':
-    ensure  => file,
-    owner   => 'root',
-    group   => 'root',
-    mode    => '0644',
-    content => template('zulip/sysctl.d/40-uwsgi.conf.erb'),
-  }
-  exec { 'sysctl_p_uwsgi':
-    command     => '/sbin/sysctl -p /etc/sysctl.d/40-uwsgi.conf',
-    subscribe   => File['/etc/sysctl.d/40-uwsgi.conf'],
-    refreshonly => true,
-    # We have to protect against running in Docker and other
-    # containerization which prevents adjusting these.
-    onlyif      => 'touch /proc/sys/net/core/somaxconn',
+  zulip::sysctl { 'uwsgi':
+    content     => template('zulip/sysctl.d/40-uwsgi.conf.erb'),
+    skip_docker => true,
   }
 
   file { [

puppet/zulip/manifests/sysctl.pp

@@ -0,0 +1,25 @@
+# @summary Adds a sysctl file, and immediately runs it.
+define zulip::sysctl (
+  $source = undef,
+  $content = undef,
+  $skip_docker = False,
+) {
+  file { "/etc/sysctl.d/40-${name}.conf":
+    ensure  => file,
+    owner   => 'root',
+    group   => 'root',
+    mode    => '0644',
+    source  => $source,
+    content => $content,
+  }
+  $onlyif = $skip_docker ? {
+    true    => 'touch /proc/sys/net/core/somaxconn',
+    default => undef,
+  }
+  exec { "sysctl_p_${name}":
+    command     => "/sbin/sysctl -p /etc/sysctl.d/40-${name}.conf",
+    subscribe   => File["/etc/sysctl.d/40-${name}.conf"],
+    refreshonly => true,
+    onlyif      => $onlyif,
+  }
+}

puppet/zulip_ops/manifests/profile/postgresql.pp

@@ -9,18 +9,9 @@ class zulip_ops::profile::postgresql {
 
   zulip_ops::firewall_allow{ 'postgresql': }
 
-  file { '/etc/sysctl.d/40-postgresql.conf':
-    ensure => file,
-    owner  => 'root',
-    group  => 'root',
-    mode   => '0644',
+  zulip::sysctl { 'postgresql':
     source => 'puppet:///modules/zulip_ops/postgresql/40-postgresql.conf',
   }
-  exec { 'sysctl_p':
-    command     => '/sbin/sysctl -p /etc/sysctl.d/40-postgresql.conf',
-    subscribe   => File['/etc/sysctl.d/40-postgresql.conf'],
-    refreshonly => true,
-  }
 
   file { '/root/setup_disks.sh':
     ensure => file,