From d372734bfd2ec88df000f9cd943137057a823088 Mon Sep 17 00:00:00 2001
From: sarthurdev <965089+sarthurdev@users.noreply.github.com>
Date: Fri, 18 Jun 2021 20:41:39 +0200
Subject: mdns: vrrp: T3635: Add ability to use mDNS repeater with VRRP

---
 interface-definitions/service_mdns-repeater.xml.in |  6 ++++
 src/conf_mode/service_mdns-repeater.py             | 38 ++++++++++++++++++++++
 src/system/keepalived-fifo.py                      |  8 +++++
 3 files changed, 52 insertions(+)

diff --git a/interface-definitions/service_mdns-repeater.xml.in b/interface-definitions/service_mdns-repeater.xml.in
index 33ef9a434..d02dac8a6 100644
--- a/interface-definitions/service_mdns-repeater.xml.in
+++ b/interface-definitions/service_mdns-repeater.xml.in
@@ -23,6 +23,12 @@
                   <multi/>
                 </properties>
               </leafNode>
+              <leafNode name="vrrp-disable">
+                <properties>
+                  <help>Disables mDNS repeater on VRRP interfaces not in MASTER state</help>
+                  <valueless/>
+                </properties>
+              </leafNode>
             </children>
           </node>
         </children>
diff --git a/src/conf_mode/service_mdns-repeater.py b/src/conf_mode/service_mdns-repeater.py
index 729518c96..c920920ed 100755
--- a/src/conf_mode/service_mdns-repeater.py
+++ b/src/conf_mode/service_mdns-repeater.py
@@ -16,10 +16,12 @@
 
 import os
 
+from json import loads
 from sys import exit
 from netifaces import ifaddresses, interfaces, AF_INET
 
 from vyos.config import Config
+from vyos.ifconfig.vrrp import VRRP
 from vyos.template import render
 from vyos.util import call
 from vyos import ConfigError
@@ -27,6 +29,7 @@ from vyos import airbag
 airbag.enable()
 
 config_file = r'/etc/default/mdns-repeater'
+vrrp_running_file = '/run/mdns_vrrp_active'
 
 def get_config(config=None):
     if config:
@@ -35,6 +38,9 @@ def get_config(config=None):
         conf = Config()
     base = ['service', 'mdns', 'repeater']
     mdns = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True)
+
+    if mdns:
+        mdns['vrrp_exists'] = conf.exists('high-availability vrrp')
     return mdns
 
 def verify(mdns):
@@ -60,6 +66,18 @@ def verify(mdns):
 
     return None
 
+# Get VRRP states from interfaces, returns only interfaces where state is MASTER
+def get_vrrp_master(interfaces):
+    json_data = loads(VRRP.collect('json'))
+    for group in json_data:
+        if 'data' in group:
+            if 'ifp_ifname' in group['data']:
+                iface = group['data']['ifp_ifname']
+                state = group['data']['state'] # 2 = Master
+                if iface in interfaces and state != 2:
+                    interfaces.remove(iface)
+    return interfaces
+
 def generate(mdns):
     if not mdns:
         return None
@@ -68,6 +86,12 @@ def generate(mdns):
         print('Warning: mDNS repeater will be deactivated because it is disabled')
         return None
 
+    if mdns['vrrp_exists'] and 'vrrp_disable' in mdns:
+        mdns['interface'] = get_vrrp_master(mdns['interface'])
+
+        if len(mdns['interface']) < 2:
+            return None
+
     render(config_file, 'mdns-repeater/mdns-repeater.tmpl', mdns)
     return None
 
@@ -76,7 +100,21 @@ def apply(mdns):
         call('systemctl stop mdns-repeater.service')
         if os.path.exists(config_file):
             os.unlink(config_file)
+
+        if os.path.exists(vrrp_running_file):
+            os.unlink(vrrp_running_file)
     else:
+        if 'vrrp_disable' not in mdns and os.path.exists(vrrp_running_file):
+            os.unlink(vrrp_running_file)
+        
+        if mdns['vrrp_exists'] and 'vrrp_disable' in mdns:
+            if not os.path.exists(vrrp_running_file):
+                os.mknod(vrrp_running_file) # vrrp script looks for this file to update mdns repeater
+
+            if len(mdns['interface']) < 2:
+                call('systemctl stop mdns-repeater.service')
+                return None
+
         call('systemctl restart mdns-repeater.service')
 
     return None
diff --git a/src/system/keepalived-fifo.py b/src/system/keepalived-fifo.py
index 7e2076820..3b4330e9b 100755
--- a/src/system/keepalived-fifo.py
+++ b/src/system/keepalived-fifo.py
@@ -37,6 +37,8 @@ logs_handler_syslog.setFormatter(logs_format)
 logger.addHandler(logs_handler_syslog)
 logger.setLevel(logging.DEBUG)
 
+mdns_running_file = '/run/mdns_vrrp_active'
+mdns_update_command = 'sudo /usr/libexec/vyos/conf_mode/service_mdns-repeater.py'
 
 # class for all operations
 class KeepalivedFifo:
@@ -121,6 +123,9 @@ class KeepalivedFifo:
                         logger.info("{} {} changed state to {}".format(n_type, n_name, n_state))
                         # check and run commands for VRRP instances
                         if n_type == 'INSTANCE':
+                            if os.path.exists(mdns_running_file):
+                                cmd(mdns_update_command)
+
                             if n_name in self.vrrp_config['vrrp_groups'] and n_state in self.vrrp_config['vrrp_groups'][n_name]:
                                 n_script = self.vrrp_config['vrrp_groups'][n_name].get(n_state)
                                 if n_script:
@@ -128,6 +133,9 @@ class KeepalivedFifo:
                         # check and run commands for VRRP sync groups
                         # currently, this is not available in VyOS CLI
                         if n_type == 'GROUP':
+                            if os.path.exists(mdns_running_file):
+                                cmd(mdns_update_command)
+                            
                             if n_name in self.vrrp_config['sync_groups'] and n_state in self.vrrp_config['sync_groups'][n_name]:
                                 n_script = self.vrrp_config['sync_groups'][n_name].get(n_state)
                                 if n_script:
-- 
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