python::virtualenv - '--system-site-packages' option

New 'systempkgs' parameter will call virtualenv with the
'--system-site-packages' option, which can greatly speed up creation in
some cases.

Author: Marc Fournier

README.md

@@ -64,11 +64,14 @@ Creates Python virtualenv.
 
 **proxy** — Proxy server to use for outbound connections. Default: none
 
+**systempkgs** — Copy system site-packages into virtualenv. Default: don't
+
 	python::virtualenv { '/var/www/project1':
 	  ensure       => present,
 	  version      => 'system',
 	  requirements => '/var/www/project1/requirements.txt',
 	  proxy        => 'http://proxy.domain.com:3128',
+	  systempkgs   => true,
 	}
 
 ### python::gunicorn

manifests/virtualenv.pp

@@ -16,13 +16,17 @@
 # [*proxy*]
 #  Proxy server to use for outbound connections. Default: none
 #
+# [*systempkgs*]
+#  Copy system site-packages into virtualenv. Default: don't
+#
 # === Examples
 #
 # python::virtualenv { '/var/www/project1':
 #   ensure       => present,
 #   version      => 'system',
 #   requirements => '/var/www/project1/requirements.txt',
 #   proxy        => 'http://proxy.domain.com:3128',
+#   systempkgs   => true,
 # }
 #
 # === Authors
@@ -33,7 +37,8 @@
   $ensure       = present,
   $version      = 'system',
   $requirements = false,
-  $proxy        = false
+  $proxy        = false,
+  $systempkgs   = false,
 ) {
 
   $venv_dir = $name
@@ -55,10 +60,15 @@
       default => "&& export http_proxy=${proxy}",
     }
 
+    $system_pkgs_flag = $systempkgs ? {
+      false    => '',
+      default  => '--system-site-packages',
+    }
+
     exec { "python_virtualenv_${venv_dir}":
       command => "mkdir -p ${venv_dir} \
         ${proxy_command} \
-        && virtualenv -p `which ${python}` ${venv_dir} \
+        && virtualenv -p `which ${python}` ${system_pkgs_flag} ${venv_dir} \
         && ${venv_dir}/bin/pip install ${proxy_flag} --upgrade distribute pip",
       creates => $venv_dir,
     }

tests/virtualenv.pp

@@ -9,4 +9,5 @@
   version      => 'system',
   requirements => '/var/www/project1/requirements.txt',
   proxy        => 'http://proxy.domain.com:3128',
+  systempkgs   => true,
 }