cmd/strelaysrv: Harmonize and improve log output (ref #6492)

cmd/strelaysrv/pool.go

@@ -7,10 +7,15 @@ import (
 	"encoding/json"
 	"io/ioutil"
 	"log"
+	"net/http"
 	"net/url"
 	"time"
 )
 
+const (
+	httpStatusEnhanceYourCalm = 429
+)
+
 func poolHandler(pool string, uri *url.URL, mapping mapping) {
 	if debug {
 		log.Println("Joining", pool)
@@ -28,38 +33,62 @@ func poolHandler(pool string, uri *url.URL, mapping mapping) {
 
 		resp, err := httpClient.Post(pool, "application/json", &b)
 		if err != nil {
-			log.Println("Error joining pool", pool, err)
+			log.Printf("Error joining pool %v: HTTP request: %v", pool, err)
-		} else if resp.StatusCode == 500 {
-			bs, err := ioutil.ReadAll(resp.Body)
-			if err != nil {
-				log.Println("Failed to join", pool, "due to an internal server error. Could not read response:", err)
-			} else {
-				log.Println("Failed to join", pool, "due to an internal server error:", string(bs))
-			}
-			resp.Body.Close()
-		} else if resp.StatusCode == 429 {
-			log.Println(pool, "under load, will retry in a minute")
 			time.Sleep(time.Minute)
 			continue
-		} else if resp.StatusCode == 401 {
+		}
-			log.Println(pool, "failed to join due to IP address not matching external address. Aborting")
+
-			return
+		bs, err := ioutil.ReadAll(resp.Body)
-		} else if resp.StatusCode == 200 {
+		resp.Body.Close()
+		if err != nil {
+			log.Printf("Error joining pool %v: reading response: %v", pool, err)
+			time.Sleep(time.Minute)
+			continue
+		}
+
+		switch resp.StatusCode {
+		case http.StatusOK:
 			var x struct {
 				EvictionIn time.Duration `json:"evictionIn"`
 			}
-			err := json.NewDecoder(resp.Body).Decode(&x)
+			if err := json.NewDecoder(resp.Body).Decode(&x); err == nil {
-			if err == nil {
 				rejoin := x.EvictionIn - (x.EvictionIn / 5)
-				log.Println("Joined", pool, "rejoining in", rejoin)
+				log.Printf("Joined pool %s, rejoining in %v", pool, rejoin)
 				time.Sleep(rejoin)
 				continue
 			} else {
-				log.Println("Failed to deserialize response", err)
+				log.Printf("Joined pool %s, failed to deserialize response: %v", pool, err)
 			}
-		} else {
+
-			log.Println(pool, "unknown response type from server", resp.StatusCode)
+		case http.StatusInternalServerError:
+			log.Printf("Failed to join %v: server error", pool)
+			log.Printf("Response data: %s", bs)
+			time.Sleep(time.Minute)
+			continue
+
+		case http.StatusBadRequest:
+			log.Printf("Failed to join %v: request or check error", pool)
+			log.Printf("Response data: %s", bs)
+			time.Sleep(time.Minute)
+			continue
+
+		case httpStatusEnhanceYourCalm:
+			log.Printf("Failed to join %v: under load (rate limiting)", pool)
+			time.Sleep(time.Minute)
+			continue
+
+		case http.StatusUnauthorized:
+			log.Printf("Failed to join %v: IP address not matching external address", pool)
+			log.Println("Aborting")
+			return
+
+		default:
+			log.Printf("Failed to join %v: unexpected status code from server: %d", pool, resp.StatusCode)
+			log.Printf("Response data: %s", bs)
+			time.Sleep(time.Minute)
+			continue
 		}
+
 		time.Sleep(time.Hour)
 	}
 }