Merge pull request #10832 from hashicorp/dnephin/contrib-check-register-flows

contrib: add list of check register flows

contributing/service-discovery/README.md

@@ -2,6 +2,6 @@
 
 This section is still a work in progress.
 
-1. [catalog](./catalog.md)
+1. [Catalog](./catalog.md)
 1. [DNS Interface](./dns.md)
-1. health checking
+1. [Health Checks](./health-checks.md)

contributing/service-discovery/health-checks.md

@@ -0,0 +1,32 @@
+# Health Checks
+
+This section is still a work in progress.
+
+
+## Check Registration flows
+
+There are many paths to register a check. Many of these use different struct
+types, so to properly validate and convert a check, all of these paths must
+be reviewed and tested.
+
+1. API [/v1/catalog/register](https://www.consul.io/api-docs/catalog#register-entity) - the `Checks`
+   field on `structs.RegisterRequest`. The entrypoint is `CatalogRegister` in
+   [agent/catalog_endpoint.go].
+2. API [/v1/agent/check/register](https://www.consul.io/api-docs/agent/check#register-check) - the entrypoint
+   is `AgentRegisterCheck` in [agent/agent_endpoint.go]
+3. API [/v1/agent/service/register](https://www.consul.io/api-docs/agent/service#register-service) -
+   the `Check` or `Checks` fields on `ServiceDefinition`. The entrypoint is `AgentRegisterService`
+   in [agent/agent_endpoint.go].
+4. Config [Checks](https://www.consul.io/docs/discovery/checks) - the `Checks` and `Check` fields
+   on `config.Config` in [agent/config/config.go].
+5. Config [Service.Checks](https://www.consul.io/docs/discovery/services) - the
+   `Checks` and `Check` fields on `ServiceDefinition` in [agent/config/config.go].
+6. CLI [consul services register](https://www.consul.io/commands/services/register) - the
+   `Checks` and `Check` fields on `api.AgentServiceRegistration`. The entrypoint is
+   `ServicesFromFiles` in [command/services/config.go].
+
+
+[agent/catalog_endpoint.go]: https://github.com/hashicorp/consul/blob/main/agent/catalog_endpoint.go
+[agent/agent_endpoint.go]: https://github.com/hashicorp/consul/blob/main/agent/agent_endpoint.go
+[agent/config/config.go]: https://github.com/hashicorp/consul/blob/main/agent/config/config.go
+[command/services/config.go]: https://github.com/hashicorp/consul/blob/main/command/services/config.go