Debian family: install NSS libraries when managing resolved

Fixes #526.

Author: kenyon

REFERENCE.md

@@ -115,6 +115,7 @@ The following parameters are available in the `systemd` class:
 * [`manage_resolved`](#-systemd--manage_resolved)
 * [`resolved_ensure`](#-systemd--resolved_ensure)
 * [`resolved_package`](#-systemd--resolved_package)
+* [`resolved_libraries`](#-systemd--resolved_libraries)
 * [`manage_nspawn`](#-systemd--manage_nspawn)
 * [`nspawn_package`](#-systemd--nspawn_package)
 * [`dns`](#-systemd--dns)
@@ -253,6 +254,14 @@ The name of a systemd sub package needed for systemd-resolved if one needs to be
 
 Default value: `undef`
 
+##### <a name="-systemd--resolved_libraries"></a>`resolved_libraries`
+
+Data type: `Array[String[1]]`
+
+List of library packages needed for systemd-resolved.
+
+Default value: `[]`
+
 ##### <a name="-systemd--manage_nspawn"></a>`manage_nspawn`
 
 Data type: `Boolean`

data/Debian-family.yaml

@@ -2,3 +2,7 @@
 systemd::nspawn_package: 'systemd-container'
 systemd::journal_upload::package_name: 'systemd-journal-remote'
 systemd::journal_remote::package_name: 'systemd-journal-remote'
+systemd::resolved_libraries:
+  - libnss-myhostname
+  - libnss-resolve
+  - libnss-systemd

manifests/init.pp

@@ -31,6 +31,9 @@
 # @param resolved_package
 #   The name of a systemd sub package needed for systemd-resolved if one needs to be installed.
 #
+# @param resolved_libraries
+#   List of library packages needed for systemd-resolved.
+#
 # @param manage_nspawn
 #   Manage the systemd-nspawn@service and machinectl subsystem.
 #
@@ -260,6 +263,7 @@
   Stdlib::CreateResources                             $unit_files = {},
   Boolean                                             $manage_resolved = false,
   Optional[Enum['systemd-resolved']]                  $resolved_package = undef,
+  Array[String[1]]                                    $resolved_libraries = [],
   Enum['stopped','running']                           $resolved_ensure = 'running',
   Optional[Variant[Array[String],String]]             $dns = undef,
   Optional[Variant[Array[String],String]]             $fallback_dns = undef,

manifests/install.pp

@@ -14,9 +14,17 @@
     }
   }
 
-  if $systemd::manage_resolved and $systemd::resolved_package {
-    package { $systemd::resolved_package:
-      ensure => present,
+  if $systemd::manage_resolved {
+    if $systemd::resolved_package {
+      package { $systemd::resolved_package:
+        ensure => installed,
+      }
+    }
+
+    $systemd::resolved_libraries.each |String[1] $pkg| {
+      package { $pkg:
+        ensure => installed,
+      }
     }
   }