Introduce role to application rp configuration. (#1662)

* Introduce role to application rp configuration.

* Role doesn't support hot load.
* Role can be overrided by environment variables.

Signed-off-by: Pan Li <[email protected]>

* Make more consistent with app services behavior

* oops

Co-authored-by: Trask Stalnaker <[email protected]>

Author: Incarnation-p-lee

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/wasbootstrap/configuration/ConfigurationBuilder.java

@@ -291,6 +291,14 @@ private static void overlayRpConfiguration(Configuration config, RpConfiguration
         if (rpConfiguration.ignoreRemoteParentNotSampled != null) {
             config.preview.ignoreRemoteParentNotSampled = rpConfiguration.ignoreRemoteParentNotSampled;
         }
+        if (isTrimEmpty(config.role.name)) {
+            // only use rp configuration role name as a fallback, similar to WEBSITE_SITE_NAME
+            config.role.name = rpConfiguration.role.name;
+        }
+        if (isTrimEmpty(config.role.instance)) {
+            // only use rp configuration role name as a fallback, similar to WEBSITE_INSTANCE_ID
+            config.role.instance = rpConfiguration.role.instance;
+        }
     }
 
     private static String getConfigPath() {

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/wasbootstrap/configuration/RpConfiguration.java

@@ -21,6 +21,8 @@
 
 package com.microsoft.applicationinsights.agent.internal.wasbootstrap.configuration;
 
+import com.microsoft.applicationinsights.agent.internal.wasbootstrap.configuration.Configuration.Role;
+import com.microsoft.applicationinsights.agent.internal.wasbootstrap.configuration.Configuration.Sampling;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.nio.file.Path;
@@ -38,12 +40,12 @@ public class RpConfiguration {
     // intentionally null, so that we can tell if rp is providing or not
     public Sampling sampling = new Sampling();
 
+    // this is needed in Azure Spring Cloud because it will set the role name to application name
+    // on behalf of customers by default.
+    // Note the role doesn't support hot load due to unnecessary currently.
+    public Role role = new Role();
+
     // this is needed in Azure Functions because .NET SDK always propagates trace flags "00" (not sampled)
     // null means do not override the users selection
     public @Nullable Boolean ignoreRemoteParentNotSampled;
-
-    public static class Sampling {
-
-        public double percentage = 100;
-    }
 }