Put failure results on one log line

prober/http_test.go

@@ -920,18 +920,15 @@ func TestFailIfNotSSLLogMsg(t *testing.T) {
 		},
 	} {
 		t.Run(title, func(t *testing.T) {
-			recorder := logRecorder{next: promslog.NewNopLogger()}
 			registry := prometheus.NewRegistry()
 			testCTX, cancel := context.WithTimeout(context.Background(), Timeout)
 			defer cancel()
 
-			logger := slog.New(&recorder)
-			result := ProbeHTTP(testCTX, tc.URL, tc.Config, registry, logger)
-			result.log(logger, 1)
+			result := ProbeHTTP(testCTX, tc.URL, tc.Config, registry, promslog.NewNopLogger())
 			if result.success != tc.Success {
 				t.Fatalf("Expected success=%v, got=%v", tc.Success, result)
 			}
-			if seen := recorder.msgs[Msg]; seen != tc.MessageExpected {
+			if seen := result.failureReason == Msg; seen != tc.MessageExpected {
 				t.Fatalf("SSL message expected=%v, seen=%v", tc.MessageExpected, seen)
 			}
 		})

prober/prober.go

@@ -58,7 +58,7 @@ func (r *ProbeResult) failureInfoGauge() *prometheus.GaugeVec {
 	} else if r.failureReason == "" {
 		// Should not happen, but there theoretically might be an
 		// inconsistent state of the struct.
-		r.failureReason = "unknown"
+		r.failureReason = "Unkown"
 	}
 
 	labels := []string{"reason"}
@@ -85,15 +85,18 @@ func (r *ProbeResult) log(logger *slog.Logger, duration float64) {
 		if r.failureReason == "" {
 			// Should not happen, but there theoretically might be an
 			// inconsistent state of the struct.
-			r.failureReason = "unknown"
+			r.failureReason = "Probe failed for unkown reason"
 		}
 		// converting the []string slice to an []any slice is a bit finicky
-		logDetails := make([]any, 0, len(r.failureDetails)+2)
+		logDetails := make([]any, 0, len(r.failureDetails)+4)
+		logDetails = append(logDetails, "reason")
+		logDetails = append(logDetails, r.failureReason)
 		for _, d := range r.failureDetails {
 			logDetails = append(logDetails, d)
 		}
-		logger.Error(r.failureReason, logDetails...)
-		logger.Error("Probe failed", "duration_seconds", duration)
+		logDetails = append(logDetails, "duration")
+		logDetails = append(logDetails, duration)
+		logger.Error("Probe failed", logDetails...)
 	}
 }