Add endpoint for serving i18n requests

For now JSON service is not available without authentication
to IPA. But some of Web UI pages expect translations before
or without Login process. This endpoint serves i18n requests
only.

Fixes: https://pagure.io/freeipa/issue/7559
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Petr Vobornik <pvoborni@redhat.com>

ipaserver/plugins/xmlserver.py

@@ -29,11 +29,12 @@ register = Registry()
 
 if api.env.context in ('server', 'lite'):
     from ipaserver.rpcserver import (
-        wsgi_dispatch, xmlserver, jsonserver_kerb, jsonserver_session,
-        login_kerberos, login_x509, login_password, change_password,
-        sync_token, xmlserver_session)
+        wsgi_dispatch, xmlserver, jsonserver_i18n_messages, jsonserver_kerb,
+        jsonserver_session, login_kerberos, login_x509, login_password,
+        change_password, sync_token, xmlserver_session)
     register()(wsgi_dispatch)
     register()(xmlserver)
+    register()(jsonserver_i18n_messages)
     register()(jsonserver_kerb)
     register()(jsonserver_session)
     register()(login_kerberos)

ipaserver/rpcserver.py

@@ -41,6 +41,7 @@ import six
 from six.moves.urllib.parse import parse_qs
 from six.moves.xmlrpc_client import Fault
 # pylint: enable=import-error
+from six import BytesIO
 
 from ipalib import plugable, errors
 from ipalib.capabilities import VERSION_WITHOUT_CAPABILITIES
@@ -784,6 +785,49 @@ class xmlserver(KerberosWSGIExecutioner):
         return dump.encode('utf-8')
 
 
+class jsonserver_i18n_messages(jsonserver):
+    """
+    JSON RPC server for i18n messages only.
+    """
+
+    key = '/i18n_messages'
+
+    def not_allowed(self, start_response):
+        status = '405 Method Not Allowed'
+        headers = [('Allow', 'POST')]
+        response = b''
+
+        logger.debug('jsonserver_i18n_messages: %s', status)
+        start_response(status, headers)
+        return [response]
+
+    def forbidden(self, start_response):
+        status = '403 Forbidden'
+        headers = []
+        response = b'Invalid RPC command'
+
+        logger.debug('jsonserver_i18n_messages: %s', status)
+        start_response(status, headers)
+        return [response]
+
+    def __call__(self, environ, start_response):
+        logger.debug('WSGI jsonserver_i18n_messages.__call__:')
+        if environ['REQUEST_METHOD'] != 'POST':
+            return self.not_allowed(start_response)
+
+        data = read_input(environ)
+        unmarshal_data = super(jsonserver_i18n_messages, self
+                               ).unmarshal(data)
+        name = unmarshal_data[0] if unmarshal_data else ''
+        if name != 'i18n_messages':
+            return self.forbidden(start_response)
+
+        environ['wsgi.input'] = BytesIO(data.encode('utf-8'))
+        response = super(jsonserver_i18n_messages, self
+                         ).__call__(environ, start_response)
+        return response
+
+
 class jsonserver_session(jsonserver, KerberosSession):
     """
     JSON RPC server protected with session auth.