[ntp] add ntp support in buster with mgmt vrf

[bsun-sudo]

- What I did
change in Buster dev for NTP with mgmt vrf

- How I did it

• create a file in files/image_config/ntp/ntp-systemd-wrapper to add mgmt vrf related start cmd for ntp service. So that the default /usr/lib/ntp/ntp-systemd-wrapper can be overriden during build time.
• modify build_debian.sh to cp files/image_config/ntp/ntp-systemd-wrapper to /usr/lib/ntp/ntp-systemd-wrapper during build time.

- How to verify it

- config ntp add xx.xx.xx.xx
- check ntpstat, ntpq -pn
- config mgmt vrf
- check "ip vrf exec mgmt ntpstat" , ip vrf exec mgmt ntpq -pn"
- service ntp start
- service ntp stop
- service ntp status

root@sonic:~# show mgmt-vrf

ManagementVRF : Disabled


root@sonic:~# config ntp add 10.11.0.1
NTP server 10.11.0.1 added to configuration
Restarting ntp-config service...
root@sonic:~#


root@sonic:~# service ntp status
● ntp.service - Network Time Service
   Loaded: loaded (/lib/systemd/system/ntp.service; enabled; vendor preset: enab
   Active: active (running) since Wed 2020-03-25 04:00:42 UTC; 19s ago
     Docs: man:ntpd(8)
  Process: 15898 ExecStart=/usr/lib/ntp/ntp-systemd-wrapper (code=exited, status
 Main PID: 15908 (ntpd)
    Tasks: 2 (limit: 4915)
   Memory: 1.8M
   CGroup: /system.slice/ntp.service
           └─15908 /usr/sbin/ntpd -p /var/run/ntpd.pid -x -u 105:110


oot@sonic:~# ntpstat
synchronised to NTP server (10.11.0.1) at stratum 4
   time correct to within 1940 ms
   polling server every 64 s
root@sonic:~#
root@sonic:~#
root@sonic:~# ntpq -pn
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*10.11.0.1       10.14.2.1        3 u   34   64    1    0.241  -1625.8   0.231
root@sonic:~#


root@sonic:~# config vrf add mgmt
root@sonic:~# show mgmt-vrf

ManagementVRF : Enabled

Management VRF interfaces in Linux:
40: mgmt: <NOARP,MASTER,UP,LOWER_UP> mtu 65536 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether f6:a6:52:de:0c:46 brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 68 maxmtu 1500
    vrf table 5000 addrgenmode eui64 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master mgmt state UP mode DEFAULT group default qlen 1000
    link/ether 3c:2c:30:1f:9f:80 brd ff:ff:ff:ff:ff:ff
41: lo-m: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue master mgmt state UNKNOWN mode DEFAULT group default qlen 1000
    link/ether e2:bc:53:eb:a8:57 brd ff:ff:ff:ff:ff:ff


root@sonic:~# ip vrf exec mgmt ntpstat
synchronised to NTP server (10.11.0.1) at stratum 4
   time correct to within 1755 ms
   polling server every 64 s
root@sonic:~#
root@sonic:~#
root@sonic:~# ip vrf exec mgmt ntpq -pn
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*10.11.0.1       10.14.2.1        3 u   50   64    3    0.210  -1563.0  25.494


root@sonic:~# service ntp status
● ntp.service - Network Time Service
   Loaded: loaded (/lib/systemd/system/ntp.service; enabled; vendor preset: enab
   Active: active (running) since Wed 2020-03-25 04:02:21 UTC; 2min 32s ago
     Docs: man:ntpd(8)
  Process: 16104 ExecStart=/usr/lib/ntp/ntp-systemd-wrapper (code=exited, status
    Tasks: 2 (limit: 4915)
   Memory: 2.0M
   CGroup: /system.slice/ntp.service
           └─vrf
             └─mgmt
               └─16114 /usr/sbin/ntpd -p /var/run/ntpd.pid -x -u 105:110


root@sonic:~# service ntp restart
root@sonic:~#
root@sonic:~#
root@sonic:~#
root@sonic:~# ip vrf exec mgmt ntpstat
synchronised to NTP server (10.11.0.1) at stratum 4
   time correct to within 1817 ms
   polling server every 64 s
root@sonic:~#
root@sonic:~#
root@sonic:~# ip vrf exec mgmt ntpq -pn
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*10.11.0.1       10.14.2.1        3 u   10   64    1    0.426  -1500.2   6.994
root@sonic:~#
root@sonic:~#
root@sonic:~# service ntp status
● ntp.service - Network Time Service
   Loaded: loaded (/lib/systemd/system/ntp.service; enabled; vendor preset: enab
   Active: active (running) since Wed 2020-03-25 04:05:17 UTC; 35s ago
     Docs: man:ntpd(8)
  Process: 16208 ExecStart=/usr/lib/ntp/ntp-systemd-wrapper (code=exited, status
    Tasks: 2 (limit: 4915)
   Memory: 1.8M
   CGroup: /system.slice/ntp.service
           └─vrf
             └─mgmt
               └─16219 /usr/sbin/ntpd -p /var/run/ntpd.pid -x -u 105:110