This state requires the
augeas Python module.
Augeas can be used to manage configuration files.
Minimal installations of Debian and Ubuntu have been seen to have packaging bugs with python-augeas, causing the augeas module to fail to import. If the minion has the augeas module installed, and the state fails with a comment saying that the state is unavailable, first restart the salt-minion service. If the problem persists past that, the following command can be run from the master to determine what is causing the import to fail:
salt minion-id cmd.run 'python -c "from augeas import Augeas"'
For affected Debian/Ubuntu hosts, installing
libpython2.7 has been
known to resolve the issue.
change(name, context=None, changes=None, lens=None, load_path=None, **kwargs)¶
This state replaces
Issue changes to Augeas, optionally for a specific context, with a specific lens.
A file path, prefixed by
/files. Should resolve to an actual file
(not an arbitrary augeas path). This is used to avoid duplicating the
file name for each item in the changes list (for example,
set bind 0.0.0.0
in the example below operates on the file specified by
context is not specified, a file path prefixed by
/files should be
included with the
The file path is examined to determine if the specified changes are already present.
redis-conf: augeas.change: - context: /files/etc/redis/redis.conf - changes: - set bind 0.0.0.0 - set maxmemory 1G
bind parameter in
redis-conf: augeas.change: - changes: - set /files/etc/redis/redis.conf/bind 0.0.0.0
context parameter to specify the file you want to
manipulate. This way you don't have to include this in the changes
redis-conf: augeas.change: - context: /files/etc/redis/redis.conf - changes: - set bind 0.0.0.0 - set databases 4 - set maxmemory 1G
Augeas is aware of a lot of common configuration files and their syntax. It knows the difference between for example ini and yaml files, but also files with very specific syntax, like the hosts file. This is done with lenses, which provide mappings between the Augeas tree and the file.
There are many preconfigured lenses that come with Augeas by default, and they specify the common locations for configuration files. So most of the time Augeas will know how to manipulate a file. In the event that you need to manipulate a file that Augeas doesn't know about, you can specify the lens to use like this:
redis-conf: augeas.change: - lens: redis - context: /files/etc/redis/redis.conf - changes: - set bind 0.0.0.0
Even though Augeas knows that
/etc/redis/redis.conf is a Redis
configuration file and knows how to parse it, it is recommended to
specify the lens anyway. This is because by default, Augeas loads all
known lenses and their associated file paths. All these files are
parsed when Augeas is loaded, which can take some time. When specifying
a lens, Augeas is loaded with only that lens, which speeds things up
quite a bit.
A more complex example, this adds an entry to the services file for Zabbix, and removes an obsolete service:
zabbix-service: augeas.change: - lens: services - context: /files/etc/services - changes: - ins service-name after service-name[last()] - set service-name[last()] zabbix-agent - set service-name[. = 'zabbix-agent']/#comment "Zabbix Agent service" - set service-name[. = 'zabbix-agent']/port 10050 - set service-name[. = 'zabbix-agent']/protocol tcp - rm service-name[. = 'im-obsolete'] - unless: grep "zabbix-agent" /etc/services
Don't forget the
unless here, otherwise a new entry will be added
every time this state is run.