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.
+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.
+See also
+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 indentation level starting -with a - character:
+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
@@ -190,13 +202,6 @@ with a - character:
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
@@ -204,18 +209,20 @@ name: John Eckersberg
job: Developer
skill: Elite
Like lists, dictionaries can be represented in an abbreviated form:
+Dictionaries can also be represented in an abbreviated form if you really want to:
---
# An employee record
{name: John Eckersberg, job: Developer, skill: Elite}
You can specify a boolean value (true/false) in several forms:
+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
Finally, you can combine these data structures:
+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
@@ -237,8 +244,10 @@ languages:
© Copyright 2012 Michael DeHaan.
- Last updated on Mar 10, 2012.
+ Last updated on Mar 11, 2012.
Created using Sphinx 1.0.8.
© Copyright 2012 Michael DeHaan.
- Last updated on Mar 10, 2012.
+ Last updated on Mar 11, 2012.
Created using Sphinx 1.0.8.
© Copyright 2012 Michael DeHaan.
- Last updated on Mar 10, 2012.
+ Last updated on Mar 11, 2012.
Created using Sphinx 1.0.8.
It also excels for writing distributed scripts and ad-hoc applications that need to gather data or perform arbitrary tasks – whether for a QA sytem, build system, or anything you can think of.
+See also
+
© Copyright 2012 Michael DeHaan.
- Last updated on Mar 10, 2012.
+ Last updated on Mar 11, 2012.
Created using Sphinx 1.0.8.
© Copyright 2012 Michael DeHaan.
- Last updated on Mar 10, 2012.
+ Last updated on Mar 11, 2012.
Created using Sphinx 1.0.8.
ansible all /bin/echo hello
Congratulations. You’ve just contacted your nodes with Ansible. It’s -now time to read some of the more real-world examples, and explore +now time to read some of the more real-world Command Line Examples, and explore what you can do with different modules, as well as the Ansible -playbooks language. Ansible is not just about running commands, but +Playbooks language. Ansible is not just about running commands, but you already have a working infrastructure!
See also
© Copyright 2012 Michael DeHaan.
- Last updated on Mar 10, 2012.
+ Last updated on Mar 11, 2012.
Created using Sphinx 1.0.8.
© Copyright 2012 Michael DeHaan.
- Last updated on Mar 10, 2012.
+ Last updated on Mar 11, 2012.
Created using Sphinx 1.0.8.