chef-auto-patch

Description

Chef Cookbook for automatically patching nodes on a specific schedule (weekday,
hour, and minute). Handles weekly or monthly patching routines with or without
node splay for large environments. Can automatically prepare node for true patch
window by cleaning and pre-downloading packages, which speeds up patch process
and can help guarantee meeting patching timeframes.

If you're looking for daily upgrades on Ubuntu, check out the
unattended-upgrades package
and a corresponding cookbook.
(/ht @hectcastro for this information).

Requirements

Platforms

• RedHat 6.3 (Santiago)
• Ubuntu 12.04 (Precise)

Cookbooks

• cron

Attributes

• node["auto-patch"]["disable"] - defaults to false
• node["auto-patch"]["hour"] - defaults to 3
• node["auto-patch"]["minute"] - defaults to 0
• node["auto-patch"]["monthly"] - auto patching occurs once a month on the corresponding textual week number ("first","second",etc) and weekday ("monday","tuesday",etc), overridden by node["auto-patch"]["weekly"], defaults to "first sunday"
• node["auto-patch"]["reboot"] - reboot automatically after patching, defaults to true
• node["auto-patch"]["splay"] - seconds of random delay before beginning, defaults to 0
• node["auto-patch"]["weekly"] - auto patching occurs once a week on the corresponding textual weekday ("monday","tuesday",etc), overrides node["auto-patch"]["monthly"], defaults to nil

Patch Preparation

• node["auto-patch"]["prep"]["clean"] - cleans updater cache files, defaults to true
• node["auto-patch"]["prep"]["disable"] - defaults to true
• node["auto-patch"]["prep"]["hour"] - defaults to 2
• node["auto-patch"]["prep"]["minute"] - defaults to 0
• node["auto-patch"]["prep"]["monthly"] - auto patching prep occurs once a month on the corresponding textual week number ("first","second",etc) and weekday ("monday","tuesday",etc), overridden by node["auto-patch"]["prep"]["weekly"], defaults to "first sunday"
• node["auto-patch"]["prep"]["splay"] - seconds of random delay before beginning, defaults to 1800
• node["auto-patch"]["prep"]["weekly"] - auto patching prep occurs once a week on the corresponding textual weekday ("monday","tuesday",etc), overrides node["auto-patch"]["prep"]["monthly"], defaults to nil
• node["auto-patch"]["prep"]["update_updater"] - updates apt or yum before actual patching occurs, defaults to true

Recipes

• recipe[auto-patch] configures automatic patching

Usage

• Change any attributes to fit your patching cycle
• If using auto patch preparation, ensure it starts before auto patch (remember any splay!)
• Add recipe[auto-patch] to your node's run list

Weekly automatic patching

Just use the node["auto-patch"]["weekly"] attribute to override the monthly
setting. Don't forget to add appropriate node["auto-patch"]["prep"]["weekly"]
if you're using automatic patch preparation.

Automatic patching of large numbers of nodes

If you're auto patching many nodes at once, you have two attributes you can
optionally add to prevent denial of service against your network, update
server(s), and resources:
* Adding node["auto-patch"]["splay"]
* Setting node["auto-patch"]["prep"]["disable"] to false (along with setting
associated prep attributes to meet your patch cycle)

Using roles to specify auto patching groups

If you'd like to specify groups of nodes for auto patching, you can setup roles.

Say you want to auto patch some nodes at 8am and some at 10pm on your monthly
"patch day" of the fourth Wednesday every month.

If you have a base role (you do, right?), you can save duplicating attributes
and specify some base information first:

"auto-patch" => {
  "monthly" => "fourth wednesday",
  "prep" => {
    "disable" => false,
    "hour" => 7,
    "monthly" => "fourth wednesday"
  }
}

Example role that then could be added to 8am nodes:

name "auto-patch-0800"
description "Role for automatically patching nodes at 8am on patch day."
default_attributes(
  "auto-patch" => {
    "hour" => 8
  }
)
run_list(
  "recipe[auto-patch]"
)

Example role that then could be added to 10pm nodes:

name "auto-patch-2200"
description "Role for automatically patching nodes at 10pm on patch day."
default_attributes(
  "auto-patch" => {
    "hour" => 22
  }
)
run_list(
  "recipe[auto-patch]"
)

Disabling automatic patching

• Specify node["auto-patch"]["disable"] to true
• If necessary, specify node["auto-patch"]["prep"]["disable"] to true
• Run chef-client on your node

Contributing

Please use standard Github issues/pull requests.

License and Author

Author:: Brian Flad (bflad@wharton.upenn.edu)

Copyright:: 2012

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.