allow all python versions

Fixes issue #448, "Impossible to use version number in Ubuntu 16.04"

1) It does not make sense to restrict the allowed python versions per
distribution. Newer distribution releases add new python versions and
you can add repositories containing backports.
2) The List was outdated.

Note:
python version is needed for spec test

manifests/init.pp

@@ -62,8 +62,9 @@
   }
 
   $allowed_versions = concat(['system', 'pypy'], $valid_versions)
-  unless $version =~ Enum[$allowed_versions] {
-    fail("version needs to be within${allowed_versions}")
+  unless $version =~ Pattern[/\A(python)?[0-9](\.[0-9])+/,
+        /\Apypy\Z/, /\Asystem\Z/] {
+    fail("version needs to be pypy, system or a version string like '3.5' or 'python3.5)")
   }
 
   # Module compatibility check

manifests/install.pp

@@ -9,7 +9,8 @@
   $python = $::python::version ? {
     'system' => 'python',
     'pypy'   => 'pypy',
-    default  => "${python::version}", # lint:ignore:only_variable_string
+    /\A(python)?([0-9](\.[0-9])+)/ => "python${1}",
+    default  => "python${python::version}",
   }
 
   $pythondev = $::osfamily ? {

manifests/params.pp

@@ -10,12 +10,7 @@
   $gunicorn               = 'absent'
   $manage_gunicorn        = true
   $provider               = undef
-  $valid_versions = $::osfamily ? {
-    'RedHat' => ['3','27','33'],
-    'Debian' => ['3', '3.3', '2.7'],
-    'Suse'   => [],
-    'Gentoo' => ['2.7', '3.3', '3.4', '3.5']
-  }
+  $valid_versions         = undef
 
   if $::osfamily == 'RedHat' {
     if $::operatingsystem != 'Fedora' {

manifests/pyvenv.pp

@@ -37,15 +37,15 @@
 
   if $ensure == 'present' {
     $python_version = $version ? {
-        'system' => "$::python3_version",
-        default  => "${version}",
+        'system' => $facts['python3_version'],
+        default  => $version,
     }
 
     # Debian splits the venv module into a seperate package
     if ( $facts['os']['family'] == 'Debian'){
       $python3_venv_package="python${python_version}-venv"
-      case $facts['os']['distro']['codename'] {
-         'xenial','bionic','cosmic','disco',
+      case $facts['lsbdistcodename'] {
+        'xenial','bionic','cosmic','disco',
         'jessie','stretch','buster': {
           package {$python3_venv_package:
             before => File[$venv_dir],
@@ -56,7 +56,7 @@
     }
 
     # pyvenv is deprecated since 3.6 and will be removed in 3.8
-    if (versioncmp($::python3_version, '3.6') >=0) {
+    if (versioncmp($facts['python3_version'], '3.6') >=0) {
       $virtualenv_cmd = "${python::exec_prefix}python${python_version}  -m venv"
     } else {
       $virtualenv_cmd = "${python::exec_prefix}pyvenv-${python_version}"

spec/default_module_facts.yml

@@ -0,0 +1,3 @@
+---
+python_version: "2.7"
+python3_version: ~

spec/defines/pyvenv_spec.rb

@@ -4,15 +4,18 @@
   on_supported_os.each do |os, facts|
     context("on #{os} ") do
       let :facts do
-        facts
+        # python3 is required to use pyvenv
+        facts.merge(
+          python3_version: '3.4'
+        )
       end
       let :title do
         '/opt/env'
       end
 
       it {
         is_expected.to contain_file('/opt/env')
-        is_expected.to contain_exec('python_virtualenv_/opt/env').with_command('pyvenv --clear  /opt/env')
+        is_expected.to contain_exec('python_virtualenv_/opt/env').with_command('pyvenv-3.4 --clear  /opt/env')
       }
 
       describe 'when ensure' do
@@ -28,6 +31,6 @@
           }
         end
       end
-    end
+    end # context
   end
 end