Keep wireguard keys Sensitive and generate missing private keys

hieradata/common.yaml

@@ -178,6 +178,8 @@ lookup_options:
     convert_to: Sensitive
   stalwart::fallback_admin_password:
     convert_to: Sensitive
+  wireguard::interfaces:
+    convert_to: Sensitive
 
 facts_path: '/opt/puppetlabs/facter/facts.d'
 

modules/wireguard/manifests/init.pp

@@ -0,0 +1,44 @@
+# manage wireguard interfaces via wg-quick
+class wireguard (
+  Boolean                        $manage_package = true,
+  String                         $package_name   = 'wireguard-tools',
+  Variant[Hash, Sensitive[Hash]] $interfaces = {},
+) {
+
+  if $manage_package {
+    package { $package_name:
+      ensure => installed,
+      before => File['/etc/wireguard'],
+    }
+  }
+
+  file { '/etc/wireguard':
+    ensure => directory,
+    owner  => 'root',
+    group  => 'root',
+    mode   => '0700',
+  }
+
+  # hiera hands eyaml secrets over as plain strings inside the (Sensitive) hash; re-wrap them per resource
+  $raw = $interfaces ? {
+    Sensitive => $interfaces.unwrap,
+    default   => $interfaces,
+  }
+
+  $raw.each |String $iface, Hash $data| {
+    $peers = $data.get('peers', []).map |Hash $peer| {
+      $peer['preshared_key'] =~ String ? {
+        true    => $peer + { 'preshared_key' => Sensitive($peer['preshared_key']) },
+        default => $peer,
+      }
+    }
+    $private_key = $data['private_key'] =~ String ? {
+      true    => Sensitive($data['private_key']),
+      default => $data['private_key'],
+    }
+
+    wireguard::interface { $iface:
+      * => $data + { 'peers' => $peers, 'private_key' => $private_key },
+    }
+  }
+}

modules/wireguard/manifests/interface.pp

@@ -0,0 +1,63 @@
+# manage one wg-quick interface; without private_key, /etc/wireguard/<iface>.key is generated once and loaded via PostUp
+define wireguard::interface (
+  Array[Stdlib::IP::Address]           $addresses,
+  Optional[Stdlib::Port]               $listen_port = undef,
+  Optional[Integer[1280, 9000]]        $mtu         = undef,
+  Optional[Sensitive[String[1]]]       $private_key = undef,
+  Array[Struct[{
+    public_key           => String[1],
+    allowed_ips          => Variant[String[1], Array[String[1], 1]],
+    preshared_key        => Optional[Sensitive[String[1]]],
+    endpoint             => Optional[String[1]],
+    persistent_keepalive => Optional[Integer[0, 65535]],
+  }]]                                  $peers       = [],
+) {
+
+  $conf = "/etc/wireguard/${name}.conf"
+  $key  = $private_key.then |$k| { $k.unwrap }
+
+  if $private_key =~ Undef {
+    $keyfile = "/etc/wireguard/${name}.key"
+
+    exec { "wireguard_genkey_${name}":
+      command => "/bin/sh -c 'umask 077; wg genkey > ${keyfile}'",
+      creates => $keyfile,
+      path    => ['/usr/bin', '/usr/sbin', '/bin', '/sbin'],
+      require => File['/etc/wireguard'],
+    }
+
+    file { $keyfile:
+      ensure  => file,
+      owner   => 'root',
+      group   => 'root',
+      mode    => '0600',
+      require => Exec["wireguard_genkey_${name}"],
+      before  => [File[$conf], Service["wg-quick@${name}"]],
+    }
+  }
+
+  file { $conf:
+    ensure    => file,
+    owner     => 'root',
+    group     => 'root',
+    mode      => '0600',
+    content   => Sensitive(template('wireguard/wg.conf.erb')),
+    show_diff => false,
+    notify    => Exec["wireguard_syncconf_${name}"],
+  }
+
+  service { "wg-quick@${name}":
+    ensure  => running,
+    enable  => true,
+    require => File[$conf],
+  }
+
+  # syncconf applies peer/key changes without bouncing the tunnel; address/mtu changes need a manual restart
+  exec { "wireguard_syncconf_${name}":
+    command     => "/bin/bash -c 'wg syncconf ${name} <(wg-quick strip ${name})'",
+    onlyif      => "/usr/sbin/ip link show ${name}",
+    path        => ['/usr/bin', '/usr/sbin', '/bin', '/sbin'],
+    refreshonly => true,
+    require     => Service["wg-quick@${name}"],
+  }
+}

modules/wireguard/templates/wg.conf.erb

@@ -0,0 +1,31 @@
+# THIS FILE IS MANAGED BY PUPPET
+[Interface]
+<% @addresses.each do |addr| -%>
+Address = <%= addr %>
+<% end -%>
+<% if @listen_port -%>
+ListenPort = <%= @listen_port %>
+<% end -%>
+<% if @mtu -%>
+MTU = <%= @mtu %>
+<% end -%>
+<% if @key -%>
+PrivateKey = <%= @key %>
+<% else -%>
+PostUp = wg set %i private-key /etc/wireguard/%i.key
+<% end -%>
+<% @peers.each do |peer| -%>
+
+[Peer]
+PublicKey = <%= peer['public_key'] %>
+<% if peer['preshared_key'] -%>
+PresharedKey = <%= peer['preshared_key'].unwrap %>
+<% end -%>
+AllowedIPs = <%= Array(peer['allowed_ips']).join(', ') %>
+<% if peer['endpoint'] -%>
+Endpoint = <%= peer['endpoint'] %>
+<% end -%>
+<% if peer['persistent_keepalive'] -%>
+PersistentKeepalive = <%= peer['persistent_keepalive'] %>
+<% end -%>
+<% end -%>