[ntp] enable/disable NTP long jump according to reboot type (#4577)

* [ntp] enable/disable NTP long jump according to reboot type

- Enable NTP long jump after cold reboot.
- Disable NTP long jump after warrm/fast reboot.

Signed-off-by: Ying Xie <ying.xie@microsoft.com>

* fix typo

* further refactoring

* use sonic-db-cli instead

files/image_config/ntp/ntp-config.sh

@@ -1,5 +1,37 @@
 #!/bin/bash
 
+ntp_default_file='/etc/default/ntp'
+ntp_temp_file='/tmp/ntp.orig'
+
+reboot_type='cold'
+
+function get_database_reboot_type()
+{
+    SYSTEM_WARM_START=`sonic-db-cli STATE_DB hget "WARM_RESTART_ENABLE_TABLE|system" enable`
+    SYSTEM_FAST_START=`sonic-db-cli STATE_DB get "FAST_REBOOT|system"`
+
+    if [[ x"${SYSTEM_WARM_START}" == x"true" ]]; then
+        reboot_type='warm'
+    elif [[ x"${SYSTEM_FAST_START}" == x"1" ]]; then
+        reboot_type='fast'
+    fi
+}
+
+function modify_ntp_default
+{
+    cp ${ntp_default_file} ${ntp_temp_file}
+    sed -e "$1" ${ntp_temp_file} >${ntp_default_file}
+}
+
 sonic-cfggen -d -t /usr/share/sonic/templates/ntp.conf.j2 >/etc/ntp.conf
 
+get_database_reboot_type
+if [[ x"${reboot_type}" == x"cold" ]]; then
+    echo "Enabling NTP long jump for reboot type ${reboot_type} ..."
+    modify_ntp_default "s/NTPD_OPTS='-x'/NTPD_OPTS='-g'/"
+else
+    echo "Disabling NTP long jump for reboot type ${reboot_type} ..."
+    modify_ntp_default "s/NTPD_OPTS='-g'/NTPD_OPTS='-x'/"
+fi
+
 systemctl restart ntp