Added upgrade script to update AJP loopback address.

An upgrade script has been added to replace IPv4- and IPv6-specific
AJP loopback address with a more generic "localhost" in existing
instances.

https://fedorahosted.org/pki/ticket/2570

base/common/upgrade/10.4.0/.gitignore

@@ -0,0 +1,4 @@
+# Ignore everything in this directory
+*
+# Except this file
+!.gitignore

base/server/upgrade/10.4.0/01-UpdateAJPLoopbackAddress

@@ -0,0 +1,62 @@
+#!/usr/bin/python
+# Authors:
+#     Endi S. Dewata <edewata@redhat.com>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# Copyright (C) 2017 Red Hat, Inc.
+# All rights reserved.
+#
+
+from __future__ import absolute_import
+import os
+from lxml import etree
+
+import pki
+
+
+class UpdateAJPLoopbackAddress(
+        pki.server.upgrade.PKIServerUpgradeScriptlet):
+
+    def __init__(self):
+        super(UpdateAJPLoopbackAddress, self).__init__()
+        self.message = 'Update AJP loopback address'
+
+        self.parser = etree.XMLParser(remove_blank_text=True)
+
+    def upgrade_instance(self, instance):
+
+        server_xml = os.path.join(instance.conf_dir, 'server.xml')
+        self.backup(server_xml)
+
+        document = etree.parse(server_xml, self.parser)
+
+        server = document.getroot()
+        connectors = server.findall('.//Connector')
+
+        # replace IPv4- or IPv6-specific AJP loopback address with localhost
+        for connector in connectors:
+
+            protocol = connector.get('protocol')
+            if protocol != 'AJP/1.3':
+                continue
+
+            address = connector.get('address')
+            if address != '127.0.0.1' and address != '::1':
+                continue
+
+            connector.set('address', 'localhost')
+
+        with open(server_xml, 'wb') as f:
+            document.write(f, pretty_print=True, encoding='utf-8')