Add hostNetwork DNSPolicy support

[zzjin]

And add support listen port under 1024 (like 443).

What type of PR is this?
fix: fix new introduced hostNetwork cannot speak to xds bug.

May fix: #2310

[github-actions]

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[Xunzhuo]

Plz fix the CI and make sure it is backport compatible.

[shawnh2]

just out of curiosity, is there any better way to improve this looong hideous nested nil check?

[Xunzhuo]

refer to https://github.com/envoyproxy/gateway/blob/main/api/v1alpha1/envoygateway_helpers.go#L80

make it as a common helper to use

[shawnh2]

hi @zzjin, you can try make testdata to automatically generate the correct test data.

[arkodg]

we shouldnt be changing the container port logic, all clients should access the gateway via the service

[Xunzhuo]

@arkodg Any better solutions for using EG in such scenarios:

1. a kubernetes cluster without lb implementation
2. expose envoyproxy with 80/443

In this scenario, EG is more like a real loadbalancer, it should be a common request.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (a723843) 64.67% compared to head (d2fb176) 64.73%.
Report is 113 commits behind head on main.

❗ Current head d2fb176 differs from pull request most recent head e4e662c. Consider uploading reports for the commit e4e662c to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2309      +/-   ##
==========================================
+ Coverage   64.67%   64.73%   +0.06%     
==========================================
  Files         114      114              
  Lines       16618    16633      +15     
==========================================
+ Hits        10747    10767      +20     
+ Misses       5193     5188       -5     
  Partials      678      678              

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[arkodg]

@Xunzhuo you can route to the service port (80/443) via External IP

[Xunzhuo]

@arkodg Can you elaborate it ?

[arkodg]

@arkodg Can you elaborate it ?

https://www.fadhil-blog.dev/blog/kubernetes-external-ip/

[Xunzhuo]

Correct ... @arkodg I think I missed this, thanks for pointing out.

[github-actions]

This pull request has been automatically marked as stale because it has not had activity in the last 30 days. Please feel free to give a status update now, ping for review, when it's ready. Thank you for your contributions!

[Xunzhuo]

close via #2374