change apipa network gw address from .1 to .2

[ZetaoZhuang]

Reason for Change:

currently cns using the same ip address "169.254.128.1" for both apipa gw and loopback adapter. This cause conflict issue when hns get restarted and not able to rehydrate the apipa endpoints. our long-term goal is to make this gw address configurable in dnc. But for a short-term fix, in cns, we want to overwrite the address to 169.254.128.2, so customer can recreate apipa endpoints by restarting the cns.
Issue Fixed:

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• relevant PR labels added

Notes:

[rbtr]

what's the impact of this change? is it backwards compatible?

[ZetaoZhuang]

here are some screenshots from my set up to test this change

vm ipconfig

container ipconfig

[rbtr]

thanks for adding this context. what happens if this change goes out to a node where containers are already running with the old .1 address?

[ZetaoZhuang]

thanks for adding this context. what happens if this change goes out to a node where containers are already running with the old .1 address?

This change only applies on new created apipa network/endpoints. It does not impact existed containers unless recreate them. @ashvindeodhar

[tamilmani1989]

thanks for adding this context. what happens if this change goes out to a node where containers are already running with the old .1 address?

@ZetaoZhuang did we test this with existing clusters with old cns and new cni, with all combinations?

[github-actions]

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[github-actions]

Pull request closed due to inactivity.

[QxBytes]

A couple clarifications:

• how do the apipa gw and loopback adapter come up the first time with no restart if they both use 169.254.128.1?
• is the long term fix that we get the gw address from elsewhere and cns consumes it?
• is the hns default gw address not changeable?

[ZetaoZhuang]

A couple clarifications:

• how do the apipa gw and loopback adapter come up the first time with no restart if they both use 169.254.128.1?
  hns allows this the first time with no restart
• is the long term fix that we get the gw address from elsewhere and cns consumes it?
  yep. cns get it from dnc
• is the hns default gw address not changeable?
  atm, right

[behzad-mir]

Please add a TODO to redesign the hnsclient on windows

[ZetaoZhuang]

/azp run Azure Container Networking PR

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