[BUG] subnet and vpc can't use same name： vpc与subnet不能重名

[yachongli]

Kube-OVN Version

1.13.2

Kubernetes Version

ex v1.13.2

Operation-system/Kernel Version

1

Description

If the vpc and subnet have the same name, two datapaths with the same name will appear in the datapath table of the south database, causing confusion in the flow table.

如果vpc和subnet同名，南向的datapath表中就会有两个相同的datapath出现，进而导致流表下发的失败。建议在创建的时候加以限制，或者添加一个中间名来解决。

Steps To Reproduce

1

Current Behavior

1

Expected Behavior

1

[dosubot]

To address the issue of VPC and subnet having the same name in Kube-OVN, you can implement validation hooks to prevent their creation with identical names. Specifically, use the VpcCreateHook and SubnetCreateHook functions. These functions check for naming conflicts and return an error if a VPC and subnet share the same name, thereby preventing duplicate datapaths in the south database.

Here's a brief overview of how these hooks work:

• VpcCreateHook: Located in pkg/webhook/vpc.go, this function checks if a subnet with the same name as the VPC already exists and returns an error to prevent the creation of the VPC ^[1].

• SubnetCreateHook: Found in pkg/webhook/subnet.go, this function performs a similar check to ensure that a subnet cannot be created with the same name as an existing VPC ^[2].

Implementing these hooks will help avoid confusion in the flow table by ensuring unique names for VPCs and subnets.

To continue talking to Dosu, mention @dosu.

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[yachongli]

进一步的来说，subnet和vpc判断时不仅仅需要查看相同的资源的名称是否有重复，也应该互相检查对方的资源中和自己有没有重复。

[yachongli]

应该是卡timing了，webhook中是有subnet与vpc不能同名的判断的，但本地cache的更新时间是一秒。 如果我把创建vpc和subnet写到一个yaml中，它们的创建速度是以0.1秒为单位的，这就导致实际上本地的vpc_cache并没有更新到刚刚创建的vpc?

[yachongli]

如果在subnetCreateWebhook中添加一个v.cache.WaitForCacheSync(ctx)呢？估计也不行，业务上为了方便肯定是像编排一样把资源都写入到一个yaml中，极端情况下subnet可能会被先行定义出来。

建议加两个判断：
1、webhook中加一个判断，如果subnet的结构体中包含的vpc的名称与自己一致，不允许通过。在create_subnet和update_subnet时都添加。
2、更进一步的，在controller层也添加判断。

[yachongli]

[hugo345816]

这个问题很早前就有了，之前说是ovn的datapath问题，所以一直没有解决。

[yachongli]

这个问题很早前就有了，之前说是ovn的datapath问题，所以一直没有解决。

@hugo345816 datapath不能重名这没有问题，但我提交这个bug的意思是：kubeovn已经判断了不能重名，但没有考虑到同时创建的问题，导致没有限制住。所以需要在创建subnet时也判断下spec.vpc是否与当前subnet同名。

[oilbeater]

看上去确实是一个时序的问题，vpc 和 subnet 如果并行处理就会有概率检查失效。