fix: Restore /config endpoint and correct handlerFunc for buildinfo (#4027)

As far as I can tell from reading the "next" documentation, the
/loki/api/v1/status/buildinfo endpoint should return the build
information. The /version endpoint is also listed further down in the
documentation but from the code prior to this change, it looks like it
should perform the same function as buildinfo endpoint so I have
removed it.

I've updated the documentation to reflect my changes.

Signed-off-by: Jack Baldry <jack.baldry@grafana.com>

docs/sources/api/_index.md

@@ -19,7 +19,7 @@ These endpoints are exposed by all components:
 - [`GET /ready`](#get-ready)
 - [`GET /metrics`](#get-metrics)
 - [`GET /config`](#get-config)
-- [`GET /loki/api/v1/status/buildinfo`](#get-buildinfo)
+- [`GET /loki/api/v1/status/buildinfo`](#get-lokiapiv1statusbuildinfo)
 
 These endpoints are exposed by the querier and the frontend:
 
@@ -824,12 +824,10 @@ and the current are returned. A value of `defaults` returns the default configur
 
 In microservices mode, the `/config` endpoint is exposed by all components.
 
-## `GET buildinfo`
+## `GET /loki/api/v1/status/buildinfo`
 
 `/loki/api/v1/status/buildinfo` exposes the build information in a JSON object. The fields are `version`, `revision`, `branch`, `buildDate`, `buildUser`, and `goVersion`.
 
-In microservices mode, the `/version` endpoint is exposed by all components.
-
 ## Series
 
 The Series API is available under the following:

pkg/loki/loki.go

@@ -261,10 +261,10 @@ func (t *Loki) Run() error {
 	t.Server.HTTP.Path("/ready").Handler(t.readyHandler(sm))
 
 	// This adds a way to see the config and the changes compared to the defaults
-	t.Server.HTTP.Path("/loki/api/v1/status/buildinfo").HandlerFunc(configHandler(t.Cfg, newDefaultConfig()))
+	t.Server.HTTP.Path("/config").HandlerFunc(configHandler(t.Cfg, newDefaultConfig()))
 
 	// Each component serves its version.
-	t.Server.HTTP.Path("/version").HandlerFunc(versionHandler())
+	t.Server.HTTP.Path("/loki/api/v1/status/buildinfo").HandlerFunc(versionHandler())
 
 	t.Server.HTTP.Path("/debug/fgprof").Handler(fgprof.Handler())