feat(translator): support disabling X-RateLimit headers

[evacchi]

Signed-off-by: Edoardo Vacchi evacchi@users.noreply.github.com

What this PR does / why we need it:

This PR exposes EnableXRatelimitHeaders as a Gateway flag. For backwards compatibility, it flips the semantics (Disable vs Enable) as to preserve the current default semantics, i.e. always emit.

[arkodg]

hey @evacchi raised #3400 to track this, will bring this up in the community meeting tomorrow and see what others think is the best home for this knob

[zirain]

for my personal, API > Annotaions > Env flags.

[evacchi]

compare this to:

gateway/internal/xds/translator/testdata/out/xds-ir/ratelimit.listeners.yaml

Lines 17 to 26 in 329aafc

	- name: envoy.filters.http.ratelimit
	typedConfig:
	'@type': type.googleapis.com/envoy.extensions.filters.http.ratelimit.v3.RateLimit
	domain: first-listener
	enableXRatelimitHeaders: DRAFT_VERSION_03
	rateLimitService:
	grpcService:
	envoyGrpc:
	clusterName: ratelimit_cluster
	transportApiVersion: V3

the config headers.disableRateLimitHeaders: true causes the line

 enableXRatelimitHeaders: DRAFT_VERSION_03

to be omitted, because OFF is the zero value and marshalling is configured as omitempty

[arkodg]

hey @evacchi thanks for updating the PR with the API change, added some minor comments
would be good to also add 1 test case within the gateway-api lib to avoid regressions
https://github.com/envoyproxy/gateway/tree/main/internal/gatewayapi/testdata

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 67.81%. Comparing base (76c08e6) to head (e334073).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3397      +/-   ##
==========================================
+ Coverage   67.77%   67.81%   +0.03%     
==========================================
  Files         166      166              
  Lines       20037    20041       +4     
==========================================
+ Hits        13581    13591      +10     
+ Misses       5466     5461       -5     
+ Partials      990      989       -1     

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[arkodg]

LGTM thanks !

[guydc]

Should we add an E2E to the RL suite for this case?

[evacchi]

Attempting to add an e2e test, I think it should be correct but I do appreciate another set of eyes (also I am having some trouble with my local dev setup, so I'll have to figure that out...)

[guydc]

LGTM