What Is YAML?

Ismail ALABOU
Jan 15 · 4 min read
Image for post
Image for post
YAML

Definition

Overview

Features of YAML

How YAML Works

integer: 25 
string: "25"
float: 25.0
boolean: Yes
--- # Shopping List in Block Format 
- milk
- eggs
- juice
--- # Shopping List in Inline Format [milk, eggs, juice]
data: |
Each of these
Newlines
Will be broken up
data: >
This text is
wrapped and will
be formed into
a single paragraph

YAML vs. JSON

{
"json": [
"rigid",
"better for data interchange"
],
"yaml": [
"slim and flexible",
"better for configuration"
],
"object": {
"key": "value",
"array": [
{
"null_value": null
},
{
"boolean": true
},
{
"integer": 1
}
]
},
"paragraph": "Blank lines denotenparagraph breaksn",
"content": "Or wencan autonconvert line breaksnto save space"
}
---
# <- yaml supports comments, json does not # did you know you can embed json in yaml? # try uncommenting the next line # { foo: 'bar' } json: - rigid - better for data interchange yaml: - slim and flexible - better for configuration object: key: value array: - null_value: - boolean: true - integer: 1 paragraph: >
Blank lines denote

paragraph breaks
content: |-
Or we
can auto
convert line breaks
to save space

Examples of YAML

---
- hosts: webservers

vars:
http_port: 80
max_clients: 200

remote_user: root

tasks:
- name: ensure apache is at the latest version
yum:
name: httpd
state: latest

- name: write the apache config file
template:
src: /srv/httpd.j2
dest: /etc/httpd.conf
notify:
- restart apache

- name: ensure apache is running
service:
name: httpd
state: started

handlers:
- name: restart apache
service:
name: httpd
state: restarted
ansible-playbook -i hosts/groups verify_apache.yml

Key Takeaways

The Startup

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