Handling secure cookies for localhost URLs

[ahus1]

Describe the bug

Starting with keycloak/keycloak#16770 Keycloak changed its handling of secure cookies. While this works with browsers, it doesn't work with Gatling: gatling/gatling#4578

Version

main

Expected behavior

Gatling should work with URLs "localhost" when logging in using the UI.

Actual behavior

The authentication flow won't work with "localhost" addresses.

How to Reproduce?

Run the scenario keycloak.scenario.authentication.LoginUserPassword against a URL like http://localhost:8080

./bin/kcb.sh --scenario=keycloak.scenario.authentication.LoginUserPassword --server-url=http://localhost:8080 --realm-name=master --username=admin --user-password=admin --users-per-sec=30 --ramp-up=1 --client-id=test --client-secret=*** --client-redirect-uri=http://localhost:8080 --measurement=600 --log-http-on-failureLoginUserPassword

Anything else?

This is waiting for Gatling upstream to fix the issue. In the meantime, a safety switch is in place which will case an early failure and will show a descriptive error message.