Data types for cfg.py; add danube_edition entry

- Explicitly state datatype in config_items to handle them more
  generically

- Handle boolean values correctly.  Before this fix we got the string
  'False' which evaluated to True (this affected the entry
  'use_x_forwarded_host').

- Add the config entry 'danube_edition'. Activating it shows a voucher
  input field for pagekite accounts on freedombox.me during the
  firstboot process. Other vouchers (i.e. for VPN services) might
  follow.  Add description and test for 'danube_edition' setting.

plinth.config

@@ -37,3 +37,14 @@ port = 8000
 # Leave the values blank to disable
 use_x_forwarded_host = True
 secure_proxy_ssl_header = HTTP_X_FORWARDED_PROTO
+
+[Misc]
+# The danube_edition changes the firstboot process and offers entering a
+# voucher for a freedombox.me sub-domain. This functionality requires
+# additional debian packages to be installed:
+#
+# pagekite, python3-requests
+#
+# They are not added as dependencies to keep the normal installation images
+# lean, but make sure to add them if you want to build danube-edition images.
+danube_edition = False

plinth/cfg.py

@@ -39,6 +39,7 @@ secure_proxy_ssl_header = None
 debug = False
 no_daemon = False
 server_dir = '/'
+danube_edition = False
 
 main_menu = Menu()
 
@@ -66,32 +67,35 @@ def read():
         })
     parser.read(CONFIG_FILE)
 
-    config_items = {('Name', 'product_name'),
-                    ('Name', 'box_name'),
-                    ('Path', 'root'),
-                    ('Path', 'file_root'),
-                    ('Path', 'config_dir'),
-                    ('Path', 'data_dir'),
-                    ('Path', 'store_file'),
-                    ('Path', 'actions_dir'),
-                    ('Path', 'doc_dir'),
-                    ('Path', 'status_log_file'),
-                    ('Path', 'access_log_file'),
-                    ('Path', 'pidfile'),
-                    ('Path', 'server_dir'),
-                    ('Network', 'host'),
-                    ('Network', 'port'),
-                    ('Network', 'secure_proxy_ssl_header'),
-                    ('Network', 'use_x_forwarded_host')}
+    config_items = {('Name', 'product_name', 'string'),
+                    ('Name', 'box_name', 'string'),
+                    ('Path', 'root', 'string'),
+                    ('Path', 'file_root', 'string'),
+                    ('Path', 'config_dir', 'string'),
+                    ('Path', 'data_dir', 'string'),
+                    ('Path', 'store_file', 'string'),
+                    ('Path', 'actions_dir', 'string'),
+                    ('Path', 'doc_dir', 'string'),
+                    ('Path', 'status_log_file', 'string'),
+                    ('Path', 'access_log_file', 'string'),
+                    ('Path', 'pidfile', 'string'),
+                    ('Path', 'server_dir', 'string'),
+                    ('Network', 'host', 'string'),
+                    ('Network', 'port', 'int'),
+                    ('Network', 'secure_proxy_ssl_header', 'string'),
+                    ('Network', 'use_x_forwarded_host', 'bool'),
+                    ('Misc', 'danube_edition', 'bool')}
 
-    for section, name in config_items:
+    for section, name, datatype in config_items:
         try:
             value = parser.get(section, name)
-            globals()[name] = value
         except (configparser.NoSectionError, configparser.NoOptionError):
             print('Configuration does not contain the {}.{} option.'
                   .format(section, name))
             raise
-
-    global port  # pylint: disable-msg=W0603
-    port = int(port)
+        else:
+            if datatype == 'int':
+                value = int(value)
+            if datatype == 'bool':
+                value = value.lower() == 'true'
+            globals()[name] = value

plinth/tests/test_cfg.py

@@ -223,7 +223,9 @@ class CfgTestCase(unittest.TestCase):
         self.assertEqual(parser.get('Network', 'secure_proxy_ssl_header'),
                          cfg.secure_proxy_ssl_header)
         self.assertEqual(parser.get('Network', 'use_x_forwarded_host'),
-                         cfg.use_x_forwarded_host)
+                         str(cfg.use_x_forwarded_host))
+        self.assertEqual(parser.get('Misc', 'danube_edition'),
+                         str(cfg.danube_edition))
 
     def read_temp_config_file(self, test_file):
         """Read the specified test configuration file."""