feat: update log level retrieval to support CLEF-format logs ( '@l' key) (#4236)

Author: andrei-micuda

internal/container/level_guesser.go

@@ -81,7 +81,11 @@ func guessLogLevel(logEvent *LogEvent) string {
 			return "unknown"
 		}
 
-		if level, ok := value.Get("level"); ok {
+		if level, ok := value.Get("@l"); ok {
+			if level, ok := level.(string); ok {
+				return normalizeLogLevel(level)
+			}
+		} else if level, ok := value.Get("level"); ok {
 			if level, ok := level.(string); ok {
 				return normalizeLogLevel(level)
 			}
@@ -95,7 +99,9 @@ func guessLogLevel(logEvent *LogEvent) string {
 		if value == nil {
 			return "unknown"
 		}
-		if level, ok := value.Get("level"); ok {
+		if level, ok := value.Get("@l"); ok {
+			return normalizeLogLevel(level)
+		} else if level, ok := value.Get("level"); ok {
 			return normalizeLogLevel(level)
 		} else if severity, ok := value.Get("severity"); ok {
 			return normalizeLogLevel(severity)

internal/container/level_guesser_test.go

@@ -65,6 +65,24 @@ func TestGuessLogLevel(t *testing.T) {
 				orderedmap.Pair[string, any]{Key: "severity", Value: "info"},
 			),
 		), "info"},
+		{orderedmap.New[string, string](
+			orderedmap.WithInitialData(
+				orderedmap.Pair[string, string]{Key: "key", Value: "value"},
+				orderedmap.Pair[string, string]{Key: "@l", Value: "info"},
+			),
+		), "info"},
+		{orderedmap.New[string, any](
+			orderedmap.WithInitialData(
+				orderedmap.Pair[string, any]{Key: "key", Value: "value"},
+				orderedmap.Pair[string, any]{Key: "@l", Value: "debug"},
+			),
+		), "debug"},
+		{orderedmap.New[string, string](
+			orderedmap.WithInitialData(
+				orderedmap.Pair[string, string]{Key: "@l", Value: "error"},
+				orderedmap.Pair[string, string]{Key: "@t", Value: "2024-01-01T00:00:00Z"},
+			),
+		), "error"},
 		{nilOrderedMap, "unknown"},
 		{nil, "unknown"},
 	}