January 2023
Intermediate to advanced
458 pages
14h 16m
Chinese
Content preview from 可编程网络自动化
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网络配置模板
｜
155
将该模板命名为
no-http.j2
，以表示希望正常关闭交换机内置的
HTTP
服务器。也可以使用
block
语句赋予更多的灵活性。创建一个名为
yes-http.j2
的子模板，用于覆盖
block
指定的
语句块，并根据需要输出启用
HTTP
服务器的配置。
{% extends "no-http.j2" %}
{% block http %}
ip http server
ip http secure-server
{% endblock %}
这使我们可以简单地通过渲染子模板来启用
HTTP
服务器。上例中的第一行对父模板
no-https.j2
进行
了扩展，使得所有的接口配置依然会出现在渲染输出中。但是，因为渲染
了子模板，所以其中的
http
语句块会覆盖父模板中的同名语句块。这种语句块的用法非常
适合于那些可能需要更改但又无法通过传统的变量替换方式实现的配置。
更多细节可以参见
Jinja
文档的“
T
emplate Inheritance
”（模板继承）部分，最好是将其加入
浏览器收藏夹中。
6.3.7
在
Jinja
中创建变量
Jinja
允许在模板内使用
set
语句创建变量。一种常见的用例是利用变量缩短输入。有时候
你不得不通过多个嵌套目录或
Python
对象才能得到想要的值
，而且在模板中可能还要多次
用到该值。与其重复一长串属性或键，不妨通过
set
语句，使用更短的名称来代表某个值。
{% set int_desc = switch01.config.interfaces['GigabitEthernet0/1']['description'] ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.