ntpd

This cookbook installs and configures the ntpd service to syncronize the clock against network servers. The configuration can be change to also configure the system as a peer for other computers to syncronize their clocks.

Requirements

Chef 0.10.10+ and Ohai 6.10+ for platform_family use.

Platforms:

The following platforms and versions are tested and supported using test-kitchen

• CentOS 6.7, 7.0

The following platform families are supported and are assumed to work based on successful testing.

• Red Hat (rhel)
• Amazon Linux

Attributes

Please review attributes/default.rb for default values, and all attributes contain comments in the field for easier use.

Logging Options

The following attributes change whether logging is enabled and where the logs are stored.

• node['ntp']['drift_log_enabled'] - To log the drift of your system clock into a log file, defaults to true
• node['ntp']['drift_log_location'] - The location of the drift log if enabled, defaults to /var/lib/ntp/ntp.drift
• node['ntp']['log_enabled'] - To separate out the ntp log from the default syslog provider, defaults to true
• node['ntp']['log_location'] - The location of the log if enabled, defaults to /var/lib/ntp/ntp.log

Access Controls

The following attributes change how the server responds to requests.

• node['ntp']['ac_default'] - Prevents free access to the server, defaults true
• node['ntp']['ac_ignore'] - Prevents any packet accessing the ntp server, defaults false
• node['ntp']['ac_kod'] - Enables sending of the 'kiss-o'death' (KoD) packet when access violations occur, defaults to true
• node['ntp']['ac_limited'] - Denies service if the packet spacing violates the lower limits in the discard command, defaults to false
• node['ntp']['ac_discard_avg'] - Sets the minimum average packet spacing if the limited facility is enabled, defaults to 5
• node['ntp']['ac_discard_min'] - Sets the minimum packet spacing if the limited facility is enabled, defaults to 2
• node['ntp']['ac_nomodify'] - Deny ntpq and ntpdc queries which attempt to modify the state of the server, defaults to true
• node['ntp']['nopeer'] - Deny packets that would attempt to create new peer associations, defaults to true
• node['ntp']['ac_noquery'] - Deny ntpq and ntpdc queries, defaults to true
• node['ntp']['ac_noserve'] - Deny all packets except from ntpq and ntpdc, defaults to false
• node['ntp']['ac_notrap'] - Decline to provide message trap services for remote logging, defaults to true
• node['ntp']['ac_notrust'] - Deny service unless the packet is cryptographically authenticated, defaults to false
• node['ntp']['ac_version'] - Deny packets that do not match the current NTP version, defaults to false
• node['ntp']['ac_loopback_only'] - Restrict access to loopback addresses only, defaults to true

Server Modes

The following attributes determine how and where the ntpd service syncronizes the clock.

• node['ntp']['mode_server_enabled'] - Server mode creates persistent association with the servers specified in the node['ntp']['mode_servers'] attribute, defaults to true
• node['ntp']['mode_pool_enabled'] - Pool mode creates persistent association with mulitple remote servers specified in the node['ntp']['mode_servers'] attribute. The local clock can be synced to the remote clock, defaults to false
• node['ntp']['mode_peer_enabled'] - Peer Mode creates a symmetric-active association Local and Remote clocks can be sycned to each other, defaults to false
• node['ntp']['mode_servers'] - Is an array of what servers to associate the ntpd service with. It is possible to enter prefered after a server to make it the preferred server. The entries default to the general ntp.org servers, ['0.pool.ntp.org','1.pool.ntp.org','2.pool.ntp.org','3.pool.ntp.org']
• node['ntp']['mode_burst'] - Burst will send eight packets instead of one when the server is reachable, defaults to false
• node['ntp']['mode_iburst'] - iBurst will send eight packets instead of one when the server is not reachable, defaults to true

Undisciplined Clock

The following enables the use of the system undisciplined clock if all other network associations are unavailable.

• node['ntp']['use_cmos'] - Enables the use of the undiscplined system clock, defaults to false

License and Authors

• Author: Roger Delph (roger.delph@gmail.com)

Copyright 2015, Roger Delph

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.