Avocado utilities have a certain default behavior based on educated, reasonable (we hope) guesses about how users like to use their systems. Of course, different people will have different needs and/or dislike our defaults, and that’s why a configuration system is in place to help with those cases
The Avocado config file format is based on the (informal)
INI file ‘specification’, that is implemented by
ConfigParser. The format is simple and straightforward, composed by sections,
that contain a number of keys and values. Take for example a basic Avocado config file:
[datadir.paths] base_dir = /var/lib/avocado test_dir = /usr/share/doc/avocado/tests data_dir = /var/lib/avocado/data logs_dir = ~/avocado/job-results
datadir.paths section contains a number of keys, all of them related to directories used by
the test runner. The
base_dir is the base directory to other important Avocado directories, such
as log, data and test directories. You can also choose to set those other important directories by
means of the variables
logs_dir. You can do this by simply editing
the config files available.
Config file parsing order¶
Avocado starts by parsing what it calls system wide config file, that is shipped to all Avocado users on a system
/etc/avocado/avocado.conf. Then it’ll verify if there’s a local user config file, that is located
~/.config/avocado/avocado.conf. The order of the parsing matters, so the system wide file is parsed,
then the user config file is parsed last, so that the user can override values at will. There is another directory
that will be scanned by extra config files,
/etc/avocado/conf.d. This directory may contain plugin config files,
and extra additional config files that the system administrator/avocado developers might judge necessary to put there.
Please note that for base directories, if you chose a directory that can’t be properly used by Avocado (some directories
require read access, others, read and write access), Avocado will fall back to some defaults. So if your regular user
wants to write logs to
/root/avocado/logs, Avocado will not use that directory, since it can’t write files to that
place. A new location, by default
~/avocado/job-results will be selected instead.
The order of files described in this section is only valid if avocado was installed in the system. For people using
avocado from git repos (usually avocado developers), that did not install it in the system, keep in mind that avocado
will read the config files present in the git repos, and will ignore the system wide config files. Running
avocado config will let you know which files are actually being used.
Plugin config files¶
Plugins can also be configured by config files. In order to not disturb the main Avocado config file, those plugins,
if they wish so, may install additional config files to
/etc/avocado/conf.d/[pluginname].conf, that will be parsed
after the system wide config file. Users can override those values as well at the local config file level.
Considering the config for the hypothethical plugin
[salad.core] base = ceasar dressing = ceasar
If you want, you may change
dressing in your config file by simply adding a
[salad.core] new section in your
local config file, and set a different value for
Parsing order recap¶
So the file parsing order is:
In this order, meaning that what you set on your local config file may override what’s defined in the system wide files.
Please note that if avocado is running from git repos, those files will be ignored in favor of in tree configuration files. This is something that would normally only affect people developing avocado, and if you are in doubt,
avocado config will tell you exactly which files are being used in any given situation.
When avocado runs inside virtualenv than path for global config files is also changed. For example, avocado.conf comes from the virual-env path venv/etc/avocado/avocado.conf.
Order of precedence for values used in tests¶
Since you can use the config system to alter behavior and values used in tests (think paths to test programs, for example), we established the following order of precedence for variables (from least precedence to most):
- default value (from library or test code)
- global config file
- local (user) config file
- command line switch
- test parameters
So the least important value comes from the library or test code default, going all the way up to the test parameters system.
A configuration plugin is provided for users that wish to quickly see what’s defined in all sections of their Avocado configuration, after all the files are parsed in their correct resolution order. Example:
$ avocado config Config files read (in order): /etc/avocado/avocado.conf $HOME/.config/avocado/avocado.conf Section.Key Value runner.base_dir /var/lib/avocado runner.test_dir /usr/share/doc/avocado/tests runner.data_dir /var/lib/avocado/data runner.logs_dir ~/avocado/job-results
The command also shows the order in which your config files were parsed, giving you a better understanding of
what’s going on. The Section.Key nomenclature was inspired in
git config --list output.
Avocado Data Directories¶
When running tests, we are frequently looking to:
- Locate tests
- Write logs to a given location
- Grab files that will be useful for tests, such as ISO files or VM disk images
Avocado has a module dedicated to find those paths, to avoid cumbersome path manipulation magic that people had to do in previous test frameworks .
If you want to list all relevant directories for your test, you can use avocado config –datadir command to list those directories. Executing it will give you an output similar to the one seen below:
$ avocado config --datadir Config files read (in order): /etc/avocado/avocado.conf $HOME/.config/avocado/avocado.conf Avocado replaces config dirs that can't be accessed with sensible defaults. Please edit your local config file to customize values Avocado Data Directories: base $HOME/avocado tests $HOME/Code/avocado/examples/tests data $HOME/avocado/data logs $HOME/avocado/job-results
Note that, while Avocado will do its best to use the config values you provide in the config file, if it can’t write values to the locations provided, it will fall back to (we hope) reasonable defaults, and we notify the user about that in the output of the command.
The relevant API documentation and meaning of each of those data directories
avocado.core.data_dir, so it’s highly recommended you take a look.
You may set your preferred data dirs by setting them in the Avocado config files. The only exception for important data dirs here is the Avocado tmp dir, used to place temporary files used by tests. That directory will be in normal circumstances /var/tmp/avocado_XXXXX, (where XXXXX is in actuality a random string) securely created on /var/tmp/, unless the user has the $TMPDIR environment variable set, since that is customary among unix programs.
The next section of the documentation explains how you can see and set config values that modify the behavior for the Avocado utilities and plugins.
|||For example, autotest.|