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Merge pull request #3628 from jlund/yaml-syntax

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Minor cleanup of YAML Syntax documentation
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Michael DeHaan 2013-07-22 15:20:53 -07:00
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docsite/latest/rst/YAMLSyntax.rst
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@ -4,9 +4,9 @@ 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.
We use YAML because it is easier for humans to read and write than other common
data formats like XML or JSON. Further, there are libraries available in most
programming languages for working with YAML.
You may also wish to read :doc:`playbooks` at the same time to see how this
is used in practice.
@ -15,14 +15,14 @@ is used in practice.
YAML Basics
-----------
For `ansible`, nearly every YAML file starts with a list.
For Ansible, nearly every YAML file starts with a list.
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".
Ansible or not) should begin with ``---``. This is part of the YAML
format and indicates the start of a document.
All members of a list are lines beginning at the same indentation level starting
with a ``-`` (dash) character::
@ -60,7 +60,7 @@ boolean value (true/false) in several forms::
likes_emacs: TRUE
uses_cvs: false
Let's combine what we learned so far in an arbitary YAML example. This really
Let's combine what we learned so far in an arbitrary YAML example. This really
has nothing to do with Ansible, but will give you a feel for the format::
---
@ -76,16 +76,16 @@ has nothing to do with Ansible, but will give you a feel for the format::
- Mango
languages:
ruby: Elite
python: Elite
dotnet: Lame
python: Elite
dotnet: Lame
That's all you really need to know about YAML to get started writing
That's all you really need to know about YAML to start writing
`Ansible` playbooks.
Gotchas
-------
While YAML is generally friendly, the following is going to be a YAML syntax error:
While YAML is generally friendly, the following is going to result in a YAML syntax error:
foo: somebody said I should put a colon here: so I did
@ -96,7 +96,7 @@ You will want to quote any hash values using colons, like so:
And then the colon will be preserved.
Further, Ansible uses "{{ var }}" for variables. If a value after a colon starts
with a "{", YAML will think it a dictionary, so you must quote it, like so::
with a "{", YAML will think it is a dictionary, so you must quote it, like so::
foo: "{{ variable }}"