Allow multiple endpoints in Envoy clusters configured with hostnames #21655
+13
−5
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Description
Currently when Consul generates configuration for Envoy, it behaves the same for both
LOGICAL_DNS
andSTRICT_DNS
discovery types and provides only a single endpoint to Envoy in both modes. This means that when multiple hostnames are configured inSTRICT_DNS
mode, requests are not load balanced over all available hosts.This change configures Envoy with all available hostnames when the discovery type is set to
STRICT_DNS
. InLOGICAL_DNS
mode, Envoy supports only a single endpoint and so the current behaviour of Consul remains unchanged.Testing & Reproduction steps
Tested manually, as follows:
Create Consul cluster
Create 2 instances of the same service ("example-service"), with different hostnames.
Create terminating gateway, configured with "example-service" as a destination.
Fetch the Envoy config from the terminating gateway and observe that only a single hostname is present in
lb_endpoints
(since the default discovery type isLOGICAL_DNS
).Set
envoy_dns_discovery_type
to"STRICT_DNS"
in proxy-defaults.Refetch config and observe that the Envoy config now contains both hostnames in
lb_endpoints
and will load balance incoming requests across all configured endpoints.Links
PR Checklist