Add APPLICATIONINSIGHTS_SELF_DIAGNOSTICS_LEVEL (#1433)

Author: trask

agent/agent-bootstrap/src/main/java/com/microsoft/applicationinsights/agent/bootstrap/configuration/ConfigurationBuilder.java

@@ -60,6 +60,8 @@ public class ConfigurationBuilder {
 
     private static final String APPLICATIONINSIGHTS_INSTRUMENTATION_LOGGING_LEVEL = "APPLICATIONINSIGHTS_INSTRUMENTATION_LOGGING_LEVEL";
 
+    private static final String APPLICATIONINSIGHTS_SELF_DIAGNOSTICS_LEVEL = "APPLICATIONINSIGHTS_SELF_DIAGNOSTICS_LEVEL";
+
     private static final String WEBSITE_SITE_NAME = "WEBSITE_SITE_NAME";
     private static final String WEBSITE_INSTANCE_ID = "WEBSITE_INSTANCE_ID";
 
@@ -86,7 +88,7 @@ private static void loadLogCaptureEnvVar(Configuration config) {
         }
     }
 
-    private static void loadJmxMetrics(Configuration config) throws IOException {
+    private static void loadJmxMetricsEnvVar(Configuration config) throws IOException {
         String jmxMetricsEnvVarJson = overlayWithEnvVar(APPLICATIONINSIGHTS_JMX_METRICS, (String)null);
 
         // JmxMetrics env variable has higher precedence over jmxMetrics config from applicationinsights.json
@@ -98,6 +100,9 @@ private static void loadJmxMetrics(Configuration config) throws IOException {
             JsonAdapter<List<JmxMetric>> jsonAdapter = moshi.adapter(listOfJmxMetrics);
             config.jmxMetrics = jsonAdapter.fromJson(reader);
         }
+    }
+
+    private static void addDefaultJmxMetricsIfNotPresent(Configuration config) {
         if (!jmxMetricExisted(config.jmxMetrics, "java.lang:type=Threading", "ThreadCount")) {
             JmxMetric threadCountJmxMetric = new JmxMetric();
             threadCountJmxMetric.name = "Current Thread Count";
@@ -187,8 +192,12 @@ static void overlayEnvVars(Configuration config) throws IOException {
 
         config.sampling.percentage = overlayWithEnvVar(APPLICATIONINSIGHTS_SAMPLING_PERCENTAGE, config.sampling.percentage);
 
+        config.selfDiagnostics.level = overlayWithEnvVar(APPLICATIONINSIGHTS_SELF_DIAGNOSTICS_LEVEL, config.selfDiagnostics.level);
+
         loadLogCaptureEnvVar(config);
-        loadJmxMetrics(config);
+        loadJmxMetricsEnvVar(config);
+
+        addDefaultJmxMetricsIfNotPresent(config);
     }
 
     // visible for testing