dns: T1786: add proper processing of 'system disable-dhcp-nameservers'

(cherry picked from commit 4e4f1dbd745952a24d70c3e2d7dc495d675dff34)

2 files changed, 12 insertions, 10 deletions

diff --git a/src/conf_mode/host_name.py b/src/conf_mode/host_name.py
index bb1ec9597..47cf232e9 100755
--- a/src/conf_mode/host_name.py
+++ b/src/conf_mode/host_name.py
@@ -66,7 +66,7 @@ def get_config():
         hosts['nameserver'] = conf.return_values("system name-server")
 
     if conf.exists("system disable-dhcp-nameservers"):
-        hosts['no_dhcp_ns'] = conf.exists('system disable-dhcp-nameservers')
+        hosts['no_dhcp_ns'] = True
 
     # system static-host-mapping
     hosts['static_host_mapping'] = []
@@ -135,6 +135,10 @@ def apply(config):
     try:
         client = vyos.hostsd_client.Client()
 
+        # Check if disable-dhcp-nameservers is configured, and if yes - delete DNS servers added by DHCP
+        if config['no_dhcp_ns']:
+            client.delete_name_servers('dhcp-.+')
+
         client.set_host_name(config['hostname'], config['domain_name'], config['domain_search'])
 
         client.delete_name_servers(tag)
diff --git a/src/services/vyos-hostsd b/src/services/vyos-hostsd
index 5c2ea71c8..5fb7a68ab 100755
--- a/src/services/vyos-hostsd
+++ b/src/services/vyos-hostsd
@@ -22,6 +22,7 @@ import time
 import json
 import signal
 import traceback
+import re
 
 import zmq
 
@@ -154,14 +155,10 @@ def add_name_servers(data, entries, tag):
 
 def delete_name_servers(data, tag):
     name_servers = data['name_servers']
-    keys_for_deletion = []
-
-    for ns in name_servers:
-      if name_servers[ns]['tag'] == tag:
-          keys_for_deletion.append(ns)
-
-    for k in keys_for_deletion:
-      del name_servers[k]
+    regex_filter = re.compile(tag)
+    for ns in list(name_servers.keys()):
+        if regex_filter.match(name_servers[ns]['tag']):
+            del name_servers[ns]
 
 def set_host_name(state, data):
     if data['host_name']:
@@ -174,8 +171,9 @@ def set_host_name(state, data):
 def get_name_servers(state, tag):
     ns = []
     data = state['name_servers']
+    regex_filter = re.compile(tag)
     for n in data:
-        if data[n]['tag'] == tag:
+        if regex_filter.match(data[n]['tag']):
             ns.append(n)
     return ns