Metrics for events (#1601)

Updates legman to version 2, which allows the usage of the MicrometerPlugin. The plugin will collect metrics for subscriber invocations and the underlying executor.

Furthermore this change will fix the usage of wrong subject context in the asynchronous events.

scm-webapp/src/test/java/sonia/scm/event/LegmanScmEventBusTest.java

@@ -0,0 +1,101 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.event;
+
+import com.github.legman.Subscribe;
+import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.mgt.DefaultSecurityManager;
+import org.apache.shiro.subject.SimplePrincipalCollection;
+import org.apache.shiro.subject.Subject;
+import org.apache.shiro.util.ThreadContext;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+
+import static org.awaitility.Awaitility.await;
+
+@ExtendWith(MockitoExtension.class)
+class LegmanScmEventBusTest {
+
+  private LegmanScmEventBus eventBus;
+
+  @BeforeEach
+  void setUp() {
+    DefaultSecurityManager manager = new DefaultSecurityManager();
+    ThreadContext.bind(manager);
+    // we have to use a single thread executor to ensure that the
+    // same thread is used for the test. This allows us to test,
+    // that even if the same thread is used the correct subject is in place.
+    eventBus = new LegmanScmEventBus(Executors.newSingleThreadExecutor());
+  }
+
+  @AfterEach
+  void tearDown() {
+    eventBus.shutdownEventBus(new ShutdownEventBusEvent());
+    ThreadContext.unbindSubject();
+    ThreadContext.unbindSecurityManager();
+  }
+
+  @Test
+  void shouldPassShiroContext() {
+    bindSubject("dent");
+
+    PrincipalCapturingSubscriber subscriber = new PrincipalCapturingSubscriber();
+    eventBus.register(subscriber);
+    eventBus.post("first");
+
+    bindSubject("trillian");
+    eventBus.post("second");
+
+    await()
+      .atMost(1, TimeUnit.SECONDS)
+      .until(() -> "trillian".equals(subscriber.principal));
+  }
+
+  private void bindSubject(String principal) {
+    Subject dent = new Subject.Builder()
+      .authenticated(true)
+      .principals(new SimplePrincipalCollection(principal, "test"))
+      .buildSubject();
+    ThreadContext.bind(dent);
+  }
+
+  static class PrincipalCapturingSubscriber {
+
+    private Object principal;
+
+    @Subscribe
+    public void handle(String event) {
+      principal = SecurityUtils.getSubject().getPrincipal();
+    }
+
+  }
+
+}