NTP, the Network Time Protocol, is used to keep computer clocks accurate by synchronizing them over the Internet or a local network, or by following an accurate hardware receiver that interprets GPS, DCF-77, NIST or similar time signals. . This charm can be deployed alongside principle charms to enable NTP management across deployed services.
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NTP provides network based time services to ensure synchronization of time across computers.
The ntp charm is a subordinate charm that is design for use with other principle charms. It can be used in two ways:
In this mode the ntp charm is used to configure NTP in other service units to talk directly to a set of NTP time sources:
juju deploy ntp juju add-relation ntp myservice
By default this is the standard set of NTP pool servers that are configured in the ntp Ubuntu package.
However, if you have a handy atomic clock on your network which you would prefer to trust then you can use that instead:
juju set ntp source=myatomiclock.local.net
You can also specify multiple sources and peers:
juju set ntp source="mac1.local.net mac2.local.net mac3.local.net" juju set ntp peers="mac1.local.net mac2.local.net mac3.local.net"
Sources and peers should be space separated.
When you need a set of services to keep close time to each other, it may be useful to have them automatically peer with each other. This means any set of services that use the same ntp subordinate will peer together.
juju set ntp auto_peers=true
This will add all the hosts as peers to each other.
In the event that you don't wish every server on your network to talk directly to your trusted time sources, you can use this charm in-conjunction with the ntpmaster charm:
juju deploy ntp juju deploy ntpmaster juju add-relation ntp ntpmaster
This allows you to gate NTP services to a single set of servers within your control.
This might have application in more secure network environments where general outbound network access to the Internet is not avaliable or desirable and you don't have a good internal time source such as an atomic clock.
You can of course have more that one ntpmaster:
juju add-unit ntpmaster
All services that the ntp charm is subordinate to will be configured to sync with all avaliable masters.
The ntpmaster charm supports the same "source" configuration that the ntp charm does.
- (boolean) Automatically peer with other units in the same service. DEPRECATED. Please consider using the ntpmaster charm to provide sufficient peers for your environment in favour of auto_peers.
- (string) Used by the nrpe-external-master subordinate charm. A string that will be prepended to instance name to set the host name in nagios. So for instance the hostname would be something like: juju-myservice-0 If you're running multiple environments with the same services in them this allows you to differentiate between them.
- (string) A space-separated list of nagios ntpmon checks to enable. Options are "offset peers reachability sync"; if all are specified, they are combined into a single check; leave empty for no checks.
- offset peers reachability sync
- (string) A comma-separated list of nagios servicegroups. If left empty, the nagios_context will be used as the servicegroup.
- (string) Space separated list of NTP servers to use as peers for time.
- (string) Space separated list of NTP servers to use as source for time.
- (boolean) Use iburst for all servers, not just ntpmaster.