api: cookie based consistent hashing

[arkodg]

Relates to #2624

Will use this underlying feature in Envoy https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/route/v3/route_components.proto#config-route-v3-routeaction-hashpolicy-cookie

[arkodg]

have two opens questions here for @envoyproxy/gateway-maintainers and @envoyproxy/gateway-reviewers

1. should the Cookie structure get split up into two more sub fields - Existing and Generated to make it easier to divide up the cookie fields, else it can get confusing ?
2. Should the Attributes field be renamed to ExtraAttributes ?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 67.39%. Comparing base (bcaa1b0) to head (1914ea6).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3444      +/-   ##
==========================================
- Coverage   67.45%   67.39%   -0.06%     
==========================================
  Files         166      166              
  Lines       20058    20058              
==========================================
- Hits        13531    13519      -12     
- Misses       5548     5558      +10     
- Partials      979      981       +2     

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[zhaohuabing]

should the Cookie structure get split up into two more sub fields - Existing and Generated to make it easier to divide up the cookie fields, else it can get confusing ?

One Cookie structure won't cause confusion to me. Two separate structures seem excessive since there is only one optional TTL field.

Should the Attributes field be renamed to ExtraAttributes ?

Are there any "built-in" default Attributes? If not, the "Extra" is not needed.

[arkodg]

should the Cookie structure get split up into two more sub fields - Existing and Generated to make it easier to divide up the cookie fields, else it can get confusing ?

One Cookie structure won't cause confusion to me. Two separate structures seem excessive since there is only one optional TTL field.

Should the Attributes field be renamed to ExtraAttributes ?

Are there any "built-in" default Attributes? If not, the "Extra" is not needed.

TTL field translates into Max-Age attribute

[zhaohuabing]

TTL field translates into Max-Age attribute

Then "Extra" makes sense to me, though I don't have a strong preference for it.

[shawnh2]

1. should the Cookie structure get split up into two more sub fields - Existing and Generated to make it easier to divide up the cookie fields, else it can get confusing ?

2. Should the Attributes field be renamed to ExtraAttributes ?

1. Just Cookie sounds good to me, by the definition here, cookie is only be generated if it is not exist in current request. So it works more like a default option. Flattened fields with clear explanations as comments will not cause any confusion to me.

2. Attributes sounds good too.

[zhaohuabing]

LGTM thanks!