jinja2 嵌套变量

问题描述

I am currently learning jinja2 and i am unsure on how to address variables the correct way:

Here are my variables in yaml:

---
hosts:
   app201.acme.com: {eth0: {ip: 46.0.0.1, netmask: 255.255.255.255}}
   graphite.acme.com: {eth0: {ip: 46.0.0.2, netmask: 255.255.255.255},
                       eth0.1: {ip: 10.2.90.1, netmask: 255.255.255.255}}

and here the jinja2 template:

{{ fqdn }}
{% for interface in hosts[fqdn] %}
    {{ interface }}
    {{ hosts[fqdn].interface.ip }} << doesn't work
    {{ hosts[fqdn].{{ interface }}.ip }} << doesn't work
    {{ interface.ip }} << doesn't work
{% endfor %}

so currently my output looks like this since I can't access second dimension of yaml hash.

graphite.acme.com eth0.1

eth0

解决方案

The variable hosts is a dict. The correct way to access values in dict is to use [] operator.

{{ fqdn }}
{% for interface in hosts[fqdn] %}
    {{ interface }}
    {{ hosts[fqdn][interface]['ip'] }}
{% endfor %}

. operator is used to access attribute of an object.