Support DD_LOG_FORMAT_JSON (#10223)

Author: mcculls

dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java

@@ -1461,9 +1461,15 @@ private static synchronized void startDebuggerAgent(
 
   private static void configureLogger() {
     setSystemPropertyDefault(SIMPLE_LOGGER_SHOW_DATE_TIME_PROPERTY, "true");
-    setSystemPropertyDefault(SIMPLE_LOGGER_JSON_ENABLED_PROPERTY, "false");
-    String simpleLoggerJsonEnabled = SystemProperties.get(SIMPLE_LOGGER_JSON_ENABLED_PROPERTY);
-    if (simpleLoggerJsonEnabled != null && simpleLoggerJsonEnabled.equalsIgnoreCase("true")) {
+
+    String logFormatJson = ddGetProperty("dd.log.format.json");
+    if (null != logFormatJson) {
+      setSystemPropertyDefault(SIMPLE_LOGGER_JSON_ENABLED_PROPERTY, logFormatJson);
+    } else {
+      setSystemPropertyDefault(SIMPLE_LOGGER_JSON_ENABLED_PROPERTY, "false");
+    }
+
+    if (Boolean.parseBoolean(SystemProperties.get(SIMPLE_LOGGER_JSON_ENABLED_PROPERTY))) {
       setSystemPropertyDefault(
           SIMPLE_LOGGER_DATE_TIME_FORMAT_PROPERTY, SIMPLE_LOGGER_DATE_TIME_FORMAT_JSON_DEFAULT);
     } else {

metadata/supported-configurations.json

@@ -2209,6 +2209,14 @@
         "aliases": []
       }
     ],
+    "DD_LOG_FORMAT_JSON": [
+      {
+        "version": "A",
+        "type": "boolean",
+        "default": null,
+        "aliases": []
+      }
+    ],
     "DD_MEASURE_METHODS": [
       {
         "version": "A",