The Augeas tool provides a way to use Augeas to edit files that may not be completely managed.
In the simplest case, you simply tell Augeas which path to edit, and give it a sequence of commands:
<Path type="augeas" name="/etc/hosts" owner="root" group="root" mode="0644"> <Set path="01/ipaddr" value="192.168.0.1"/> <Set path="01/canonical" value="pigiron.example.com"/> <Set path="01/alias" value="pigiron"/> <Set path="01/alias" value="piggy"/> </Path>
The commands are run in document order. There’s no need to do an explicit save at the end.
These commands will be run if any of the paths do not already have the given setting. In other words, if any command has not already been run, they will all be run.
So, if the first host already has all of the specified settings, then that Path will verify successfully and nothing will be changed. But suppose the first host looks like this:
192.168.0.1 pigiron.example.com pigiron
All that is missing is the second alias, piggy. The entire Augeas script will be run in this case. It’s important, then, to ensure that all commands you use are idempotent. (For instance, the Move and Insert commands are unlikely to be useful.)
The Augeas paths are all relative to /files/etc/hosts.
The Augeas tool understands a subset of augtool commands. Valid tags are: Remove, Move, Set, Clear, SetMulti, and Insert. Refer to the official Augeas docs or the Schema below for details on the commands.
The Augeas tool also supports one additional directive, Initial, for setting initial file content when a file does not exist. For instance, the Xml lens fails to parse a file that does not exist, and, as a result, you cannot add content to it. You can use Initial to circumvent this issue:
<Path type="augeas" name="/etc/test.xml" lens="Xml" owner="root" group="root" mode="0640"> <Initial><Test/></Initial> <Set path="Test/#text" value="text content"/> </Path>
If you’re using Augeas to edit files outside of its default load path, you must manually specify the lens. For instance:
<Path type="augeas" name="/opt/jenkins/home/config.xml" lens="Xml" owner="jenkins" group="jenkins" mode="0640"> <Set path="hudson/systemMessage/#text" value="This is a Jenkins server."/> </Path>
Note that there’s no need to manually modify the load path by setting /augeas/load/<lens>/incl, nor do you have to call load explicitly.
All available Augeas commands.
Specify initial content for a file, which will be created before Augeas commands are applied if a file doesn’t exist.
Initial takes only text content, which may be the following values: string
Implementation of the Augeas rm command.
Implementation of the Augeas mv command.
Implementation of the Augeas set command.
Implementation of the Augeas clear command.
Set multiple node values at once.
Implementation of the Augeas ins command.
|before | after||No||before|
The Augeas tool is quite slow to initialize. For each <Path type="augeas" ... > entry you have, it creates a new Augeas object internally, which can take several seconds. It’s thus important to use this tool sparingly.