cmueller/ansible
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Update documentation about Jinja2 expressions in playbooks

Browse source
This commit is contained in:
Nicolas Grilly 2013-09-05 21:20:02 +02:00
parent 4bf506f683
commit aaafd9b608
2 changed files with 15 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

12
docsite/latest/rst/playbooks.rst
View file

@ -149,7 +149,17 @@ These variables can be used later in the playbook like this::
{{ varname }}
Variables are passed through the Jinja2 templating engine, and support the use of filters to modify the variable (for example: `{{ varname|int }}` ensures the variable is interpreted as an integer). To learn more about Jinja2, you can optionally see the `Jinja2 docs <http://jinja.pocoo.org/docs/>`_ - though remember that Jinja2 loops and conditionals are only for 'templates' in Ansible, in playbooks, ansible has the 'when' and 'with' keywords for conditionals and loops.
Variables are passed through the Jinja2 templating engine. Any valid Jinja2
expression can be used between the curly braces, including the use of filters
to modify the variable (for example, `{{ varname|int }}` ensures the variable is
interpreted as an integer).
Jinja2 expressions are very similar to Python and even if you are not working
with Python you should feel comfortable with them. See the `Jinja2 documentation
<http://jinja.pocoo.org/docs/templates/>`_ to learn more about the syntax.
Please note that Jinja2 loops and conditionals are only useful in Ansible
templates, not in playbooks. Use the 'when' and 'with' keywords for
conditionals and loops in Ansible playbooks.
If there are discovered variables about the system, called 'facts', these variables bubble up back into the playbook, and can be used on each system just like explicitly set variables. Ansible provides several
of these, prefixed with 'ansible', which are documented under 'setup' in the module documentation. Additionally,

7
docsite/latest/rst/playbooks2.rst
View file

@ -307,7 +307,8 @@ Sometimes you will want to skip a particular step on a particular host. This co
as simple as not installing a certain package if the operating system is a particular version,
or it could be something like performing some cleanup steps if a filesystem is getting full.
This is easy to do in Ansible, with the `when` clause, which actually is a Python expression.
This is easy to do in Ansible, with the `when` clause, which contains a Jinja2 expression (see chapter
`Playbooks <http://www.ansibleworks.com/docs/playbooks.html#vars-section>`_ for more info).
Don't panic -- it's actually pretty simple::
tasks:
@ -1130,8 +1131,8 @@ Running a task in check mode
.. versionadded:: 1.3
Sometimes you may want to have a task to be executed even in check
mode. To achieve this use the `always_run` clause on the task. Its
value is a Python expression, just like the `when` clause. In simple
mode. To achieve this, use the `always_run` clause on the task. Its
value is a Jinja2 expression, just like the `when` clause. In simple
cases a boolean YAML value would be sufficient as a value.
Example::