[SNAP] MAAS running in snap fails to start ntpd when host OS has ntp running

[Lee Trager]

I deployed Ubuntu 16.04 using MAAS and installed the MAAS snap in the deployed system so I could run in HA. ntpd in the snap fails to start because ntp in the host operating system is already running. Turning off ntp in the host operating system allowed ntpd to run in the MAAS snap.

MAAS should detect this and warn the user it cannot start ntpd while the host OS is running ntp.

From NTP log
10 May 21:23:27 ntpd[3584]: ntpd 4.2.8p10@1.3728-o Wed May 10 17:55:12 UTC 2017 (1): Starting
10 May 21:23:27 ntpd[3584]: Command line: /snap/maas/x1/bin/ntpd -n -d -c /var/snap/maas/x1/etc/ntp.conf
10 May 21:23:27 ntpd[3584]: proto: precision = 0.102 usec (-23)
Finished Parsing!!
restrict: op 1 addr 0.0.0.0 mask 0.0.0.0 mflags 00000000 flags 000005f0
restrict: op 1 addr :: mask :: mflags 00000000 flags 000005f0
restrict: op 1 addr 127.0.0.1 mask 255.255.255.255 mflags 00000000 flags 00000000
restrict: op 1 addr ::1 mask ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff mflags 00000000 flags 00000000
restrict source template mflags 4000 flags 1c0
restrict: op 1 addr (null) mask (null) mflags 00004000 flags 000001c0
move_fd: estimated max descriptors: 1024, initial socket boundary: 16
10 May 21:23:27 ntpd[3584]: unable to bind to wildcard address :: - another process may be running - EXITING

[Lee Trager (ltrager)]

Another way to view this bug is that cloud-init should not be configuring NTP to be listening on any port. If NTP is run in client only mode NTP in the container should be able to run in parallel.