mirror of
https://github.com/ansible-collections/community.general.git
synced 2024-09-14 20:13:21 +02:00
94 lines
2.5 KiB
ReStructuredText
94 lines
2.5 KiB
ReStructuredText
YAML Syntax
|
|
===========
|
|
|
|
This page provides a basic overview of correct YAML syntax, which is how Ansible
|
|
playbooks (our configuration management language) are expressed.
|
|
|
|
We use YAML because it is easier to read and write for humans than other common
|
|
data formats like XML or JSON. Further, there are libraries available for reading
|
|
and writing YAML in most programming languages.
|
|
|
|
You may also wish to read playbook examples at the same time to see how this
|
|
is used in practice.
|
|
|
|
.. seealso::
|
|
|
|
:doc:`playbooks`
|
|
See YAML examples in practice in playbooks
|
|
|
|
|
|
YAML Basics
|
|
-----------
|
|
|
|
For `ansible`, every YAML file starts with a list of things
|
|
to do. Each item in the list is a list of key/value pairs, commonly
|
|
called a "hash" or a "dictionary". So, we need to know how
|
|
to write lists and dictionaries in YAML.
|
|
|
|
There's another small quirk to YAML. All YAML files (regardless of their association with
|
|
`ansible` or not) should start with ``---``. This is just a YAML
|
|
format thing that means "this is the start of a document".
|
|
|
|
All members of a list are lines beginning at the same indentation level starting
|
|
with a ``-`` (dash) character::
|
|
|
|
---
|
|
# A list of tasty fruits
|
|
- Apple
|
|
- Orange
|
|
- Strawberry
|
|
- Mango
|
|
|
|
A dictionary is represented in a simple ``key:`` and ``value`` form::
|
|
|
|
---
|
|
# An employee record
|
|
name: John Eckersberg
|
|
job: Developer
|
|
skill: Elite
|
|
|
|
Dictionaries can also be represented in an abbreviated form if you really want to::
|
|
|
|
---
|
|
# An employee record
|
|
{name: John Eckersberg, job: Developer, skill: Elite}
|
|
|
|
.. _truthiness:
|
|
|
|
Ansible doesn't really use these too much, but you can also specify a
|
|
boolean value (true/false) in several forms::
|
|
|
|
---
|
|
knows_oop: True
|
|
likes_emacs: TRUE
|
|
uses_cvs: false
|
|
|
|
Let's combine what we learned so far in an arbitary YAML example. This really
|
|
has nothing to do with Ansible, but will give you a feel for the format::
|
|
|
|
---
|
|
# An employee record
|
|
name: John Eckersberg
|
|
job: Developer
|
|
skill: Elite
|
|
employed: True
|
|
foods:
|
|
- Apple
|
|
- Orange
|
|
- Strawberry
|
|
- Mango
|
|
languages:
|
|
ruby: Elite
|
|
python: Elite
|
|
dotnet: Lame
|
|
|
|
That's all you really need to know about YAML to get started writing
|
|
`Ansible` playbooks.
|
|
|
|
.. seealso::
|
|
|
|
:doc:`playbooks`
|
|
Learn what playbooks can do and how to write/run them.
|
|
`YAMLLint <http://yamllint.com/>`_
|
|
YAML Lint (online) helps you debug YAML syntax if you are having problems
|
|
|