YAML Format

This page provides a basic overview of correct YAML syntax, which is how Ansible playbooks (our configuration management language) are expressed. You may also wish to read playbook examples and will quickly pick this up from those.

YAML Basics

For ansible, every YAML file must be a list at it’s root-most element. Each item in the list is a dictionary. These dictionaries represent all the options you can use to write an ansible file. In addition, all YAML files (regardless of their association with ansible or not) should start with ---.

In YAML a list can be represented in two ways. In one way all members of a list are lines beginning at the same indenta`tion level starting with a - character:

---
# A list of tasty fruits
- Apple
- Orange
- Strawberry
- Mango

In the second way a list is represented as comma separated elements surrounded by square brackets. Newlines are permitted between elements:

---
# A list of tasty fruits
[apple, orange, banana, mango]

A dictionary is represented in a simple key: and value form:

---
# An employee record
name: John Eckersberg
job: Developer
skill: Elite

Like lists, dictionaries can be represented in an abbreviated form:

---
# An employee record
{name: John Eckersberg, job: Developer, skill: Elite}

You can specify a boolean value (true/false) in several forms:

---
knows_oop: True
likes_emacs: TRUE
uses_cvs: false

Finally, you can combine these data structures:

---
# 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.

See also

YAMLLint

YAML Lint gets the lint out of your YAML