Fix log messages for unready services (#2414)

* Fix log messages for unready services

Log lines now looks like

```
11:28:52 compactor: level=debug ts=2022-07-14T09:28:52.169964509Z caller=mimir.go:643 msg="some services are not Running: compactor: Starting"
```

Signed-off-by: Dimitar Dimitrov <dimitar.dimitrov@grafana.com>

* Remove buffers

Signed-off-by: Dimitar Dimitrov <dimitar.dimitrov@grafana.com>

* Add a space

Signed-off-by: Dimitar Dimitrov <dimitar.dimitrov@grafana.com>

* Update pkg/mimir/mimir.go

Co-authored-by: Peter Štibraný <pstibrany@gmail.com>

Co-authored-by: Peter Štibraný <pstibrany@gmail.com>

pkg/mimir/mimir.go

@@ -6,14 +6,14 @@
 package mimir
 
 import (
-	"bytes"
 	"context"
 	"flag"
 	"fmt"
 	"net/http"
 	"os"
 	"reflect"
 	"strconv"
+	"strings"
 
 	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
@@ -629,18 +629,17 @@ func (t *Mimir) Run() error {
 func (t *Mimir) readyHandler(sm *services.Manager) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		if !sm.IsHealthy() {
-			msg := bytes.Buffer{}
-			msg.WriteString("Some services are not Running:\n")
-
+			var serviceNamesStates []string
 			for name, s := range t.ServiceMap {
 				if s.State() != services.Running {
-					msg.WriteString(fmt.Sprintf("%s: %s\n", name, s.State()))
+					serviceNamesStates = append(serviceNamesStates, fmt.Sprintf("%s: %s", name, s.State()))
 				}
 			}
 
-			strMsg := msg.String()
-			level.Debug(util_log.Logger).Log(strMsg)
-			http.Error(w, strMsg, http.StatusServiceUnavailable)
+			level.Debug(util_log.Logger).Log("msg", "some services are not Running", "services", serviceNamesStates)
+
+			httpResponse := "Some services are not Running:\n" + strings.Join(serviceNamesStates, "\n")
+			http.Error(w, httpResponse, http.StatusServiceUnavailable)
 			return
 		}