backend-defaults: add backend.health.headers config

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
2024-12-05 09:35:34 +01:00
parent 45b5f3440f
commit fd5d337df4
8 changed files with 242 additions and 31 deletions
@@ -38,3 +38,29 @@ backend.add(
  }),
 );
 ```
+
+### Custom headers in health check responses
+
+While not implemented directly in the root health service, the default implementation of the [RootHttpRouter](./root-http-router.md) service includes a configuration option to set additional headers to include in health check responses. For example, you can add a `service-name` header using the following configuration:
+
+```yaml
+backend:
+  health:
+    headers:
+      service-name: my-service
+```
+
+It can be a good idea to set a header for your health check responses that
+uniquely identifies your service in a multi-service environment. This ensures
+that the health check that is configured for your service is actually hitting
+your service and not another.
+
+For example, if using Envoy you can use the [`service_name_matcher`](https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/upstream/health_checking#health-check-identity) configuration and
+set the `x-envoy-upstream-healthchecked-cluster` header to a matching value. For example:
+
+```yaml
+backend:
+  health:
+    headers:
+      x-envoy-upstream-healthchecked-cluster: my-service
+```