ejabberd: Use drop-in config component for /etc files

Tests:

- Config files are all symlinks in /etc/

- jsxc is able to connect to jabber server

- When ssh is enabled avahi-browse -a shows SSH and SFTP services. The avahi
service files are created in /etc/avahi/services/. When service is disabled,
files are removed and avahi-browse -a does not show the services.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

debian/freedombox.maintscript

@@ -94,6 +94,8 @@ rm_conffile /etc/uwsgi/apps-available/bepasty-freedombox.ini 23.10~
 rm_conffile /etc/apache2/conf-available/calibre-freedombox.conf 23.10~
 rm_conffile /etc/apache2/conf-available/cockpit-freedombox.conf 23.10~
 rm_conffile /etc/apache2/conf-available/deluge-plinth.conf 23.10~
+rm_conffile /etc/apache2/conf-available/jwchat-plinth.conf 23.10~
+rm_conffile /etc/avahi/services/xmpp-server.service 23.10~
 rm_conffile /etc/dovecot/conf.d/15-freedombox-mail.conf 23.10~
 rm_conffile /etc/dovecot/conf.d/05-freedombox-passdb.conf 23.10~
 rm_conffile /etc/dovecot/conf.d/95-freedombox-sieve.conf 23.10~

plinth/modules/ejabberd/__init__.py

@@ -10,6 +10,7 @@ from django.utils.translation import gettext_lazy as _
 
 from plinth import app as app_module
 from plinth import cfg, frontpage, menu
+from plinth.config import DropinConfigs
 from plinth.daemon import Daemon
 from plinth.modules import config
 from plinth.modules.apache.components import Webserver
@@ -50,7 +51,7 @@ class EjabberdApp(app_module.App):
 
     app_id = 'ejabberd'
 
-    _version = 6
+    _version = 7
 
     def __init__(self):
         """Create components for the app."""
@@ -79,6 +80,16 @@ class EjabberdApp(app_module.App):
         packages = Packages('packages-ejabberd', ['ejabberd'])
         self.add(packages)
 
+        dropin_configs = DropinConfigs('dropin-configs-ejabberd', [
+            '/etc/apache2/conf-available/jwchat-plinth.conf',
+        ])
+        self.add(dropin_configs)
+
+        dropin_configs = DropinConfigs('dropin-config-ejabberd-avahi', [
+            '/etc/avahi/services/xmpp-server.service',
+        ], copy_only=True)
+        self.add(dropin_configs)
+
         firewall = Firewall('firewall-ejabberd', info.name,
                             ports=['xmpp-client', 'xmpp-server',
                                    'xmpp-bosh'], is_external=True)