--- a/twisted/plugins/libervia_server.py	Tue Aug 13 09:39:33 2019 +0200
+++ b/twisted/plugins/libervia_server.py	Tue Aug 13 19:12:31 2019 +0200
@@ -41,12 +41,12 @@
 from sat.core.i18n import _
 from sat.tools import config
 
-from zope.interface import implements
+from zope.interface import implementer
 
 from twisted.python import usage
 from twisted.plugin import IPlugin
 from twisted.application.service import IServiceMaker
-import ConfigParser
+import configparser
 
 
 CONFIG_SECTION = C.APP_NAME.lower()
@@ -54,7 +54,7 @@
     import sys
 
     sys.stderr.write(
-        u"""sat module version ({sat_version}) and {current_app} version ({current_version}) mismatch
+        """sat module version ({sat_version}) and {current_app} version ({current_version}) mismatch
 
 sat module is located at {sat_path}
 libervia module is located at {libervia_path}
@@ -78,6 +78,7 @@
 
 
 def coerceConnectionType(value):  # called from Libervia.OPT_PARAMETERS
+    assert isinstance(value, str)
     allowed_values = ("http", "https", "both")
     if value not in allowed_values:
         raise ValueError(
@@ -87,35 +88,12 @@
     return value
 
 
-def coerceDataDir(value):  # called from Libervia.OPT_PARAMETERS
-    if not value:
-        # we ignore missing values
-        return u''
-    if isinstance(value, unicode):
-        # XXX: if value comes from sat.conf, it's unicode,
-        # and we need byte str here (for twisted)
-        value = value.encode("utf-8")
-    value = value.encode("utf-8")
-    html = os.path.join(value, C.HTML_DIR)
-    if not os.path.isfile(os.path.join(html, C.LIBERVIA_MAIN_PAGE)):
-        raise ValueError(
-            "%s is not a Libervia's browser HTML directory" % os.path.realpath(html)
-        )
-    themes_dir = os.path.join(value, C.THEMES_DIR)
-    if not os.path.isfile(os.path.join(themes_dir, "default/styles/blog.css")):
-        # XXX: we just display a message, as themes_dir is only used by legacy blog
-        #      which will be removed entirely in 0.8
-        # TODO: remove entirely legacy blog and linked options
-        print "%s is not a Libervia's server data directory" % os.path.realpath(
-            themes_dir)
-    return value
-
-
 def coerceBool(value):
     return C.bool(value)
 
 
 def coerceUnicode(value):
+    assert isinstance(value, str)
     # XXX: we use this method to check which value to convert to Unicode
     #      but we don't do the conversion here as Twisted expect str
     return value
@@ -124,45 +102,43 @@
 DATA_DIR_DEFAULT = ''
 # options which are in sat.conf and on command line,
 # see https://twistedmatrix.com/documents/current/api/twisted.python.usage.Options.html
-OPT_PARAMETERS_BOTH = [['connection_type', 't', 'https', _(u"'http', 'https' or 'both' "
+OPT_PARAMETERS_BOTH = [['connection_type', 't', 'https', _("'http', 'https' or 'both' "
                         "(to launch both servers).").encode('utf-8'),
                         coerceConnectionType],
                        ['port', 'p', 8080,
-                        _(u'The port number to listen HTTP on.').encode('utf-8'), int],
+                        _('The port number to listen HTTP on.').encode('utf-8'), int],
                        ['port_https', 's', 8443,
-                        _(u'The port number to listen HTTPS on.').encode('utf-8'), int],
-                       ['port_https_ext', 'e', 0, _(u'The external port number used for '
-                        u'HTTPS (0 means port_https value).').encode('utf-8'), int],
-                       ['tls_private_key', '', '', _(u'TLS certificate private key (PEM '
-                        u'format)').encode('utf-8'), coerceUnicode],
-                       ['tls_certificate', 'c', 'libervia.pem', _(u'TLS public '
-                        u'certificate or private key and public certificate combined '
-                        u'(PEM format)').encode('utf-8'), coerceUnicode],
-                       ['tls_chain', '', '', _(u'TLS certificate intermediate chain (PEM '
-                        u'format)').encode('utf-8'), coerceUnicode],
-                       ['redirect_to_https', 'r', True, _(u'Automatically redirect from '
-                        u'HTTP to HTTPS.').encode('utf-8'), coerceBool],
-                       ['security_warning', 'w', True, _(u'Warn user that he is about to '
-                        u'connect on HTTP.').encode('utf-8'), coerceBool],
-                       ['passphrase', 'k', '', (_(u"Passphrase for the SàT profile "
-                        u"named '%s'") % C.SERVICE_PROFILE).encode('utf-8'),
+                        _('The port number to listen HTTPS on.').encode('utf-8'), int],
+                       ['port_https_ext', 'e', 0, _('The external port number used for '
+                        'HTTPS (0 means port_https value).').encode('utf-8'), int],
+                       ['tls_private_key', '', '', _('TLS certificate private key (PEM '
+                        'format)').encode('utf-8'), coerceUnicode],
+                       ['tls_certificate', 'c', 'libervia.pem', _('TLS public '
+                        'certificate or private key and public certificate combined '
+                        '(PEM format)').encode('utf-8'), coerceUnicode],
+                       ['tls_chain', '', '', _('TLS certificate intermediate chain (PEM '
+                        'format)').encode('utf-8'), coerceUnicode],
+                       ['redirect_to_https', 'r', True, _('Automatically redirect from '
+                        'HTTP to HTTPS.').encode('utf-8'), coerceBool],
+                       ['security_warning', 'w', True, _('Warn user that he is about to '
+                        'connect on HTTP.').encode('utf-8'), coerceBool],
+                       ['passphrase', 'k', '', (_("Passphrase for the SàT profile "
+                        "named '%s'") % C.SERVICE_PROFILE).encode('utf-8'),
                         coerceUnicode],
-                       ['data_dir', 'd', DATA_DIR_DEFAULT, _(u'Data directory for '
-                        u'Libervia legacy').encode('utf-8'), coerceDataDir],
-                       ['allow_registration', '', True, _(u'Allow user to register new '
-                        u'account').encode('utf-8'), coerceBool],
+                       ['allow_registration', '', True, _('Allow user to register new '
+                        'account').encode('utf-8'), coerceBool],
                        ['base_url_ext', '', '',
-                        _(u'The external URL to use as base URL').encode('utf-8'),
+                        _('The external URL to use as base URL').encode('utf-8'),
                         coerceUnicode],
-                       ['dev_mode', 'D', False, _(u'Developer mode, automatically reload'
-                        u'modified pages').encode('utf-8'), coerceBool],
+                       ['dev_mode', 'D', False, _('Developer mode, automatically reload'
+                        'modified pages').encode('utf-8'), coerceBool],
                       ]
 # Options which are in sat.conf only
 OPT_PARAMETERS_CFG = [
     ["empty_password_allowed_warning_dangerous_list", None, "", None],
     ["vhosts_dict", None, {}, None],
     ["url_redirections_dict", None, {}, None],
-    ["menu_json", None, {u'': C.DEFAULT_MENU}, None],
+    ["menu_json", None, {'': C.DEFAULT_MENU}, None],
     ["tickets_trackers_json", None, None, None],
     ["mr_handlers_json", None, None, None],
 ]
@@ -183,7 +159,6 @@
     server.DATA_DIR_DEFAULT = DATA_DIR_DEFAULT
     server.OPT_PARAMETERS_BOTH = OPT_PARAMETERS_BOTH
     server.OPT_PARAMETERS_CFG = OPT_PARAMETERS_CFG
-    server.coerceDataDir = coerceDataDir
 
 
 class Options(usage.Options):
@@ -204,20 +179,20 @@
         # on the command line.
 
         # FIXME: must be refactored + code can be factorised with backend
-        config_parser = ConfigParser.SafeConfigParser()
+        config_parser = configparser.SafeConfigParser()
         config_parser.read(C.CONFIG_FILES)
         self.handleDeprecated(config_parser)
         for param in self.optParameters + OPT_PARAMETERS_CFG:
             name = param[0]
             try:
                 value = config.getConfig(config_parser, CONFIG_SECTION, name, Exception)
-                if isinstance(value, unicode):
-                    value = value.encode("utf-8")
+                # if isinstance(value, str):
+                #     value = value.encode("utf-8")
                 try:
                     param[2] = param[4](value)
                 except IndexError:  # the coerce method is optional
                     param[2] = value
-            except (ConfigParser.NoSectionError, ConfigParser.NoOptionError):
+            except (configparser.NoSectionError, configparser.NoOptionError):
                 pass
         usage.Options.__init__(self)
         for opt_data in OPT_PARAMETERS_CFG:
@@ -232,19 +207,19 @@
         for old, new in replacements:
             try:
                 value = config.getConfig(config_parser, CONFIG_SECTION, old, Exception)
-            except (ConfigParser.NoSectionError, ConfigParser.NoOptionError):
+            except (configparser.NoSectionError, configparser.NoOptionError):
                 pass
             else:
-                print(u"\n/!\\ Use of {old} is deprecated, please use {new} instead\n"
-                      .format(old=old, new=new))
+                print(("\n/!\\ Use of {old} is deprecated, please use {new} instead\n"
+                      .format(old=old, new=new)))
                 config_parser.set(CONFIG_SECTION, new, value)
 
 
+@implementer(IServiceMaker, IPlugin)
 class LiberviaMaker(object):
-    implements(IServiceMaker, IPlugin)
 
     tapname = C.APP_NAME_FILE
-    description = _(u"The web frontend of Salut à Toi")
+    description = _("The web frontend of Salut à Toi")
     options = Options
 
     def makeService(self, options):
@@ -259,7 +234,9 @@
             except IndexError:
                 continue
             if coerce_cb == coerceUnicode:
-                options[opt[0]] = options[opt[0]].decode("utf-8")
+                if not isinstance(options[opt[0]], str):
+                    print(f"FIXME: {opt[0]} is not unicode")
+                    options[opt[0]] = options[opt[0]].decode("utf-8")
         initialise(options.parent)
         from libervia.server import server