Add /-/healthy endpoint to Querier (thanos-io#574)

Signed-off-by: Adrien Fillon <adrien.fillon@cdiscount.com>

Author: adrien-f

CHANGELOG.md

@@ -33,6 +33,7 @@ NOTE: As semantic versioning states all 0.y.z releases can contain breaking chan
 - `thanos rule` now supports static configuration of query nodes via `--query`
 - `thanos rule` now supports file based discovery of query nodes using `--query.file-sd-config.files`
 - `thanos query` now supports file based discovery of store nodes using `--store.file-sd-config.files`
+- Add `/-/healthy` endpoint to Querier.
 
 ### Fixed
 - [#566](https://github.com/improbable-eng/thanos/issues/566) - Fixed issue whereby the Proxy Store could end up in a deadlock if there were more than 9 stores being queried and all returned an error.

cmd/thanos/query.go

@@ -366,6 +366,13 @@ func runQuery(
 		api := v1.NewAPI(logger, reg, engine, queryableCreator, enableAutodownsampling)
 		api.Register(router.WithPrefix("/api/v1"), tracer, logger)
 
+		router.Get("/-/healthy", func(w http.ResponseWriter, r *http.Request) {
+			w.WriteHeader(http.StatusOK)
+			if _, err := fmt.Fprintf(w, "Thanos Querier is Healthy.\n"); err != nil {
+				level.Error(logger).Log("msg", "Could not write health check response.")
+			}
+		})
+
 		mux := http.NewServeMux()
 		registerMetrics(mux, reg)
 		registerProfile(mux)

kube/manifests/thanos-query.yaml

@@ -36,6 +36,10 @@ spec:
           containerPort: 10901
         - name: cluster
           containerPort: 10900
+        livenessProbe:
+          httpGet:
+            path: /-/healthy
+            port: http
 ---
 apiVersion: v1
 kind: Service