Use non-routable loop back address to avoid issues with firewalls

Author: jack-berg

exporters/otlp/testing-internal/src/main/java/io/opentelemetry/exporter/otlp/testing/internal/AbstractHttpTelemetryExporterTest.java

@@ -513,7 +513,7 @@ void connectTimeout() {
     TelemetryExporter<T> exporter =
         exporterBuilder()
             // Connecting to a non-routable IP address to trigger connection error
-            .setEndpoint("http://10.255.255.1")
+            .setEndpoint("http://127.0.0.255")
             .setConnectTimeout(Duration.ofMillis(1))
             .build();
     try {

exporters/sender/jdk/src/test/java/io/opentelemetry/exporter/sender/jdk/internal/JdkHttpSenderTest.java

@@ -53,7 +53,7 @@ void setup() throws IOException, InterruptedException {
     sender =
         new JdkHttpSender(
             mockHttpClient,
-            "http://10.255.255.1", // Connecting to a non-routable IP address to trigger connection
+            "http://127.0.0.255", // Connecting to a non-routable IP address to trigger connection
             // timeout
             null,
             false,

exporters/sender/okhttp/src/test/java/io/opentelemetry/exporter/sender/okhttp/internal/RetryInterceptorTest.java

@@ -148,8 +148,7 @@ void connectTimeout() throws Exception {
 
     // Connecting to a non-routable IP address to trigger connection error
     assertThatThrownBy(
-            () ->
-                client.newCall(new Request.Builder().url("http://10.255.255.1").build()).execute())
+            () -> client.newCall(new Request.Builder().url("http://127.0.0.255").build()).execute())
         .isInstanceOf(SocketTimeoutException.class);
 
     verify(isRetryableException, times(5)).apply(any());
@@ -165,8 +164,7 @@ void nonRetryableException() throws InterruptedException {
 
     // Connecting to a non-routable IP address to trigger connection timeout
     assertThatThrownBy(
-            () ->
-                client.newCall(new Request.Builder().url("http://10.255.255.1").build()).execute())
+            () -> client.newCall(new Request.Builder().url("http://127.0.0.255").build()).execute())
         .isInstanceOf(SocketTimeoutException.class);
 
     verify(isRetryableException, times(1)).apply(any());