June 2021
Intermediate to advanced
335 pages
5h 50m
Chinese
Content preview from Kubernetes编程
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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.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.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.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.
自定义资源进阶
｜
311
• embedded
字段可以用于保存一个类似原生
Kubernetes
类型的对象，比如
一个完整的
Pod
描述
参考官方
CRD
文档了解各种声明的详细信息。
我们要介绍的最后一个主题是依赖结构化
Schema
来实现的默认值逻辑。
9.3.5
默认值
对于原生
Kubernetes
类型，它内部很多的字段都有默认值。在过去，
CRD
中
想要使用默认值只能通过准入
Webhook
（参考“
9.2
准入
Webhook
”）来实现。
从
Kubernetes 1.15
开始，通过使用上一节中介绍的
OpenAPI v3 schema
，实
现了对
CRD
默认值的直接支持（参考
http://bit.ly/2IFH8JY
）。
在
1.15
版本中，对
CRD
默认值的直接支持仍然是一个
Alpha
版本的功能，
也就是意味着它被
CustomResourceDefaulting
功能开关默认禁用。也许在
1.16
中，它就可以进入
Beta
阶段，届时就会成为一个基本的功能。
要为某些字段设置默认值，直接通过指定
OpenAPI v3 schema
中的
default
关键字来设置默认值即可。当需要对某个类型中添加字段时，这非常方便。
以“
4.3.1
自定义资源合法性验证”中介绍过的
cnat
示例为例，假设我们
想要能定制容器的镜像，并且默认使用
busybox
镜像。这时我们可以向
OpenAPI v3 schema
中添加一个字符串类型的
image
字段，并把它的默认值设
为
busybox
：
type: object
properties:
apiVersion: ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
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.