Jinja2 Syntax

Reference guide for Jinja2 templating syntax.

Basic Syntax

Syntax	Purpose	Example
`{{ }}`	Output expression	`{{ hostname }}`
`{% %}`	Statement (logic)	`{% if enabled %}`
`{# #}`	Comment	`{# This is a comment #}`

Control Structures

Conditionals

{% if enable_snmp %}
snmp-server community {{ community }} RO
{% endif %}

{% if environment == 'production' %}
logging host 10.0.0.1
{% else %}
logging host 10.0.0.2
{% endif %}

Loops

{% for server in ntp_servers %}
ntp server {{ server }}
{% endfor %}

{% for vlan in vlans %}
vlan {{ vlan.id }}
  name {{ vlan.name }}
{% endfor %}

Filters

Filters modify variable output:

{{ hostname | upper }}          {# ROUTER-01 #}
{{ hostname | lower }}          {# router-01 #}
{{ description | default('') }} {# empty if undefined #}
{{ ip | ipaddr }}               {# validate IP address #}
{{ items | join(', ') }}        {# comma-separated list #}