Add log traces to Nomulus service on GKE (#2427)

* Add log traces to Nomulus service on GKE

Add request-scope log traces to Nomulus on GKE which, unlike
AppEngine and Cloud Run etc, does not generate traces for hosted
applications. This change only affects the GKE image. It does not affect
the AppEngine services.

Log traces are added to Nomulus-generated logs in request-processing
threads. Forked threads are not covered yet. The single relevant use
case (TimeLimiter) will be addressed in a followup PR.

The main change is in the logging configuration:

*  Use gcp-cloud-logging's LoggingHandler

*  Add gcp-cloud-logging's TraceLoggingEnhancer to the handler.

*  Set a thread-local trace id through the TraceLoggingEnhancer in
   ServletBase on request's entry and clear it on completion.

Also removed an unused class (`RequestLogId`).

* CR

* CR

proxy/src/test/java/google/registry/proxy/GcpJsonFormatterTest.java

@@ -1,102 +0,0 @@
-// Copyright 2017 The Nomulus Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package google.registry.proxy;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.common.base.Joiner;
-import java.util.logging.Level;
-import java.util.logging.LogRecord;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
-
-/** Unit tests for {@link google.registry.proxy.GcpJsonFormatter}. */
-class GcpJsonFormatterTest {
-
-  private static final String LOGGER_NAME = "example.company.app.logger";
-  private static final String SOURCE_CLASS_NAME = "example.company.app.component.Doer";
-  private static final String SOURCE_METHOD_NAME = "doStuff";
-  private static final String MESSAGE = "Something I have to say";
-
-  private final GcpJsonFormatter formatter = new GcpJsonFormatter();
-  private final LogRecord logRecord = new LogRecord(Level.WARNING, MESSAGE);
-
-  private static String makeJson(String severity, String source, String message) {
-    return "{"
-        + Joiner.on(",")
-            .join(
-                makeJsonField("severity", severity),
-                makeJsonField("source", source),
-                makeJsonField("message", "\\n" + message))
-        + "}\n";
-  }
-
-  private static String makeJsonField(String name, String content) {
-    return Joiner.on(":").join(addQuoteAndReplaceNewline(name), addQuoteAndReplaceNewline(content));
-  }
-
-  private static String addQuoteAndReplaceNewline(String content) {
-    // This quadruple escaping is hurting my eyes.
-    return "\"" + content.replaceAll("\n", "\\\\n") + "\"";
-  }
-
-  @BeforeEach
-  void beforeEach() {
-    logRecord.setLoggerName(LOGGER_NAME);
-  }
-
-  @Test
-  void testSuccess() {
-    String actual = formatter.format(logRecord);
-    String expected = makeJson("WARNING", LOGGER_NAME, MESSAGE);
-    assertThat(actual).isEqualTo(expected);
-  }
-
-  @Test
-  void testSuccess_sourceClassAndMethod() {
-    logRecord.setSourceClassName(SOURCE_CLASS_NAME);
-    logRecord.setSourceMethodName(SOURCE_METHOD_NAME);
-    String actual = formatter.format(logRecord);
-    String expected = makeJson("WARNING", SOURCE_CLASS_NAME + " " + SOURCE_METHOD_NAME, MESSAGE);
-    assertThat(actual).isEqualTo(expected);
-  }
-
-  @Test
-  void testSuccess_multilineMessage() {
-    String multilineMessage = "First line message\nSecond line message\n";
-    logRecord.setMessage(multilineMessage);
-    String actual = formatter.format(logRecord);
-    String expected = makeJson("WARNING", LOGGER_NAME, multilineMessage);
-    assertThat(actual).isEqualTo(expected);
-  }
-
-  @Test
-  void testSuccess_withCause() {
-    Throwable throwable = new Throwable("Some reason");
-    StackTraceElement[] stacktrace = {
-      new StackTraceElement("class1", "method1", "file1", 5),
-      new StackTraceElement("class2", "method2", "file2", 10),
-    };
-    String stacktraceString =
-        "java.lang.Throwable: Some reason\\n"
-            + "\\tat class1.method1(file1:5)\\n"
-            + "\\tat class2.method2(file2:10)\\n";
-    throwable.setStackTrace(stacktrace);
-    logRecord.setThrown(throwable);
-    String actual = formatter.format(logRecord);
-    String expected = makeJson("WARNING", LOGGER_NAME, MESSAGE + "\\n" + stacktraceString);
-    assertThat(actual).isEqualTo(expected);
-  }
-}