ntp: T4456: support listening on specified interface

When clients only use DHCP for interface addressing we can not bind NTPd to
an address - as it will fail if the address changes. This commit adds support
to bind ntpd to a given interface in addition to a given address.

set system ntp interface <name>

(cherry picked from commit 6732df1edd632b56d3d02970939f51d05d4262e9)

1 files changed, 10 insertions, 3 deletions

diff --git a/data/templates/ntp/ntpd.conf.tmpl b/data/templates/ntp/ntpd.conf.tmpl
index e7afcc16b..30bfd575d 100644
--- a/data/templates/ntp/ntpd.conf.tmpl
+++ b/data/templates/ntp/ntpd.conf.tmpl
@@ -33,10 +33,17 @@ restrict {{ address|address_from_cidr }} mask {{ address|netmask_from_cidr }} no
 {%   endfor %}
 {% endif %}
 
-{% if listen_address %}
+{% if listen_address is defined or interface is defined %}
 # NTP should listen on configured addresses only
 interface ignore wildcard
-{%   for address in listen_address %}
+{%   if listen_address is defined %}
+{%     for address in listen_address %}
 interface listen {{ address }}
-{%   endfor %}
+{%     endfor %}
+{%   endif %}
+{%   if interface is defined %}
+{%     for ifname in interface %}
+interface listen {{ ifname }}
+{%     endfor %}
+{%   endif %}
 {% endif %}