Set hostname via Puppet instead of Vagrant

Vagrant >=2.2.4 errors out while trying to set the hostname of an LXC
container (<fgrehm/vagrant-lxc#481>). This
combination will soon be common in Cloud VPS instances running Debian
Buster, so work around the bug by pushing hostname setting into our
Puppet code and avoid the Vagrant built-in management for it.

Bug: T236455
Change-Id: Ib1a8fe41a8c858a8a12ecf939fb6c7e55f07704d

Vagrantfile

@@ -61,7 +61,6 @@ end
 
 Vagrant.configure('2') do |config|
   config.vm.post_up_message = 'Documentation: https://www.mediawiki.org/wiki/MediaWiki-Vagrant'
-  config.vm.hostname = mwv.boxname + '.mediawiki-vagrant.dev'
   config.package.name = 'mediawiki.box'
 
   config.ssh.forward_agent = settings[:forward_agent]
@@ -273,7 +272,8 @@ Vagrant.configure('2') do |config|
     puppet.options << '--color=false' if Vagrant::Util::Platform.windows?
 
     puppet.facter = {
-      'fqdn'                   => config.vm.hostname,
+      'hostname'               => mwv.boxname,
+      'fqdn'                   => mwv.boxname + '.mediawiki-vagrant.dev',
       'git_user'               => settings[:git_user],
       'forwarded_port'         => settings[:http_port],
       'forwarded_https_port'   => settings[:https_port],

lib/mediawiki-vagrant/environment.rb

@@ -284,7 +284,7 @@ def hiera_set(key, value)
     #
     def boxname
       @path.basename.to_s.downcase
-        .gsub(/[^a-z0-9-]+/, '-')[0..62].gsub(/^-|-/, '')
+        .gsub(/[^a-z0-9-]+/, '-')[0..62].gsub(/^-|-$/, '')
     end
 
     private

puppet/modules/mwv/manifests/hostname.pp

@@ -0,0 +1,27 @@
+# == Class: mwv::hostname
+#
+# Set the hostname of the managed vm.
+#
+# === Parameters
+#
+# [*hostname*]
+#   Bare hostname
+# [*fqdn*]
+#   Fully qualified hostname
+#
+class mwv::hostname (
+    $hostname,
+    $fqdn,
+) {
+    exec { 'set-hostname':
+        command => "/usr/bin/hostnamectl set-hostname ${hostname}",
+        unless  => "/bin/hostname -s|/bin/grep -Eq '^${hostname}'",
+    }
+    host { $fqdn:
+        ensure       => 'present',
+        ip           => '127.0.0.2',
+        host_aliases => [
+            $hostname,
+        ],
+    }
+}

puppet/modules/mwv/manifests/init.pp

@@ -93,4 +93,11 @@
         content => $timezone,
         require => Package['tzdata'],
     }
+
+    # T236455: set hostname
+    class { '::mwv::hostname':
+        stage    => 'first',
+        hostname => $::hostname,
+        fqdn     => $::fqdn,
+    }
 }