Shorten host property in network statsbeat (#2087)

* Shorten host

* Use regex

* Fix spotless

* Strict protocol

* Remove sout debugging

* Remove escape .

* Send endpointUrl when region is not found

Author: heyams

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/statsbeat/NetworkStatsbeat.java

@@ -30,6 +30,8 @@
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.function.Consumer;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 import org.checkerframework.checker.lock.qual.GuardedBy;
 
 public class NetworkStatsbeat extends BaseStatsbeat {
@@ -42,6 +44,8 @@ public class NetworkStatsbeat extends BaseStatsbeat {
   private static final String EXCEPTION_COUNT_METRIC_NAME = "Exception Count";
   private static final String BREEZE_ENDPOINT = "breeze";
 
+  private static final Pattern hostPattern = Pattern.compile("^https?://(?:www\\.)?([^/.]+)");
+
   private final Object lock = new Object();
   private final Cache<String, String> ikeyEndpointMap;
 
@@ -241,25 +245,16 @@ private double getRequestDurationAvg() {
 
   /**
    * e.g. endpointUrl 'https://westus-0.in.applicationinsights.azure.com/v2.1/track' host will
-   * return 'westus-0.in.applicationinsights.azure.com'
+   * return 'westus-0'
    */
   static String getHost(String endpointUrl) {
-    assert (endpointUrl != null && !endpointUrl.isEmpty());
-    int start = endpointUrl.indexOf("://");
-    if (start != -1) {
-      int end = endpointUrl.indexOf("/", start + 3);
-      if (end != -1) {
-        return endpointUrl.substring(start + 3, end);
-      }
-
-      return endpointUrl.substring(start + 3);
-    }
+    Matcher matcher = hostPattern.matcher(endpointUrl);
 
-    int end = endpointUrl.indexOf("/");
-    if (end != -1) {
-      return endpointUrl.substring(0, end);
+    if (matcher.find()) {
+      return matcher.group(1);
     }
 
+    // it's better to send bad endpointUrl to Statsbeat for troubleshooting.
     return endpointUrl;
   }
 }

agent/agent-tooling/src/test/java/com/microsoft/applicationinsights/agent/internal/statsbeat/NetworkStatsbeatTest.java

@@ -112,22 +112,28 @@ public void run() {
 
   @Test
   public void testGetHost() {
-    String url = "https://fake-host.applicationinsights.azure.com/v2.1/track";
-    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("fake-host.applicationinsights.azure.com");
+    String url = "https://fakehost-1.example.com/";
+    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("fakehost-1");
 
-    url = "http://fake-host.example.com/v2/track";
-    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("fake-host.example.com");
+    url = "https://fakehost-2.example.com/";
+    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("fakehost-2");
 
-    url = "http://www.fake-host.com/v2/track";
-    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("www.fake-host.com");
+    url = "http://www.fakehost-3.example.com/";
+    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("fakehost-3");
 
-    url = "www.fake-host.com/";
-    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("www.fake-host.com");
+    url = "http://www.fakehost.com/v2/track";
+    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("fakehost");
 
-    url = "http://fake-host.com";
-    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("fake-host.com");
+    url = "https://www.fakehost0-4.com/";
+    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("fakehost0-4");
 
-    url = "http://fake-host.com/";
-    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("fake-host.com");
+    url = "https://www.fakehost-5.com";
+    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("fakehost-5");
+
+    url = "https://fakehost.com";
+    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("fakehost");
+
+    url = "http://fakehost-5/";
+    assertThat(NetworkStatsbeat.getHost(url)).isEqualTo("fakehost-5");
   }
 }