Don't change ejabberd hosts or jwchat sitename when changing hostname.

Update these only when the domain name is changed.

actions/xmpp

@@ -60,6 +60,12 @@ def parse_arguments():
     hostname_change.add_argument('--new-hostname',
                                  help='New hostname')
 
+    # Update ejabberd and jwchat with new domainname
+    domainname_change = subparsers.add_parser(
+        'change-domainname',
+        help='Update ejabberd and jwchat with new domainname')
+    domainname_change.add_argument('--domainname', help='New domainname')
+
     # Register a new user account
     register = subparsers.add_parser('register',
                                      help='Register a new user account')
@@ -105,38 +111,6 @@ def subcommand_change_hostname(arguments):
     old_hostname = arguments.old_hostname
     new_hostname = arguments.new_hostname
 
-    # update jwchat's sitename, if it's installed
-    if os.path.exists(JWCHAT_CONFIG):
-        with open(JWCHAT_CONFIG, 'r') as conffile:
-            lines = conffile.readlines()
-        with open(JWCHAT_CONFIG, 'w') as conffile:
-            for line in lines:
-                if re.match(r'\s*var\s+SITENAME', line):
-                    conffile.write('var SITENAME = "' + new_hostname + '";\n')
-                else:
-                    conffile.write(line)
-    else:
-        print('Skipping configuring jwchat hostname: %s not found'
-              % JWCHAT_CONFIG)
-
-    # update ejabberd hosts
-    with open(EJABBERD_CONFIG, 'r') as conffile:
-        lines = conffile.readlines()
-    with open(EJABBERD_CONFIG, 'w') as conffile:
-        in_hosts_section = False
-        for line in lines:
-            if in_hosts_section:
-                if re.match(r'\s*-\s+"', line):
-                    conffile.write(line.replace('"' + old_hostname + '"',
-                                                '"' + new_hostname + '"'))
-                else:
-                    in_hosts_section = False
-                    conffile.write(line)
-            else:
-                if re.match(r'\s*hosts:', line):
-                    in_hosts_section = True
-                conffile.write(line)
-
     subprocess.call(['service', 'ejabberd', 'stop'])
     subprocess.call(['pkill', '-u', 'ejabberd'])
 
@@ -161,6 +135,43 @@ def subcommand_change_hostname(arguments):
               % EJABBERD_BACKUP_NEW)
 
 
+def subcommand_change_domainname(arguments):
+    """Update ejabberd and jwchat with new domainname"""
+    if not get_installed():
+        print('Failed to update XMPP domainname: ejabberd is not installed.')
+        return
+
+    domainname = arguments.domainname
+
+    # update jwchat's sitename, if it's installed
+    if os.path.exists(JWCHAT_CONFIG):
+        with open(JWCHAT_CONFIG, 'r') as conffile:
+            lines = conffile.readlines()
+        with open(JWCHAT_CONFIG, 'w') as conffile:
+            for line in lines:
+                if re.match(r'\s*var\s+SITENAME', line):
+                    conffile.write('var SITENAME = "' + domainname + '";\n')
+                else:
+                    conffile.write(line)
+    else:
+        print('Skipping configuring jwchat sitename: %s not found',
+              JWCHAT_CONFIG)
+
+    subprocess.call(['service', 'ejabberd', 'stop'])
+    subprocess.call(['pkill', '-u', 'ejabberd'])
+
+    # add new domainname to top of ejabberd hosts list
+    with open(EJABBERD_CONFIG, 'r') as conffile:
+        lines = conffile.readlines()
+    with open(EJABBERD_CONFIG, 'w') as conffile:
+        for line in lines:
+            conffile.write(line)
+            if re.match(r'\s*hosts:', line):
+                conffile.write('  - "' + domainname + '"\n')
+
+    subprocess.call(['service', 'ejabberd', 'start'])
+
+
 def subcommand_register(arguments):
     """Register a new user account"""
     if not get_installed():