Provide component status next to details

Adjust the AxonServerHealthIndicator to share a status field as well.
This status field should include the additional status "WARN" for when
one of the contexts the app is connected with, is down. To support this
thoroughly, a StatusAggregate should be included.

#1964

spring-boot-autoconfigure/src/main/java/org/axonframework/actuator/HealthStatus.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2010-2022. Axon Framework
+ *
+ * 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 org.axonframework.actuator;
+
+import org.springframework.boot.actuate.health.Status;
+
+/**
+ * Utility class holding additional {@link Status} instances.
+ *
+ * @author Steven van Beelen
+ * @author Marc Gathier
+ * @since 4.6.0
+ */
+public abstract class HealthStatus {
+
+    /**
+     * A {@link Status} suggesting the connection is still working but not at full capacity.
+     */
+    public static final Status WARN = new Status("WARN");
+}

spring-boot-autoconfigure/src/main/java/org/axonframework/actuator/AxonServerHealthIndicator.java → spring-boot-autoconfigure/src/main/java/org/axonframework/actuator/axonserver/AxonServerHealthIndicator.java

@@ -14,16 +14,25 @@
  * limitations under the License.
  */
 
-package org.axonframework.actuator;
+package org.axonframework.actuator.axonserver;
 
+import org.axonframework.actuator.HealthStatus;
 import org.axonframework.axonserver.connector.AxonServerConnectionManager;
 import org.springframework.boot.actuate.health.AbstractHealthIndicator;
 import org.springframework.boot.actuate.health.Health;
+import org.springframework.boot.actuate.health.Status;
+
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * An {@link AbstractHealthIndicator} implementation exposing the health of the connections made through the {@link
- * AxonServerConnectionManager}. Shares information per connected context under {@code
- * "{context-name}.connection.active"}.
+ * AxonServerConnectionManager}. This status is exposed through the {@code "axonServer"} component.
+ * <p>
+ * The status is regarded as {@link Status#UP} if <b>all</b> {@link AxonServerConnectionManager#connections()} are up.
+ * If one of them is down, the status is {@link HealthStatus#WARN}. If all of them are down the status will be {@link
+ * Status#DOWN}. This {@link org.springframework.boot.actuate.health.HealthIndicator} also shares connection details per
+ * context under {@code "{context-name}.connection.active"}.
  *
  * @author Steven van Beelen
  * @since 4.6.0
@@ -45,7 +54,23 @@ public AxonServerHealthIndicator(AxonServerConnectionManager connectionManager)
 
     @Override
     protected void doHealthCheck(Health.Builder builder) {
-        connectionManager.connections()
-                         .forEach((key, value) -> builder.withDetail(String.format(CONNECTION, key), value));
+        builder.up();
+
+        AtomicBoolean anyConnectionUp = new AtomicBoolean(false);
+        Map<String, Boolean> connections = connectionManager.connections();
+
+        connections.forEach((context, connectionStatus) -> {
+            if (!connectionStatus) {
+                builder.status(HealthStatus.WARN);
+            } else {
+                anyConnectionUp.compareAndSet(false, true);
+            }
+            builder.withDetail(String.format(CONNECTION, context),
+                               connectionStatus ? Status.UP.getCode() : Status.DOWN.getCode());
+        });
+
+        if (!connections.isEmpty() && !anyConnectionUp.get()) {
+            builder.down();
+        }
     }
 }

spring-boot-autoconfigure/src/main/java/org/axonframework/actuator/axonserver/AxonServerStatusAggregator.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2010-2022. Axon Framework
+ *
+ * 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 org.axonframework.actuator.axonserver;
+
+import org.axonframework.actuator.HealthStatus;
+import org.springframework.boot.actuate.health.SimpleStatusAggregator;
+import org.springframework.boot.actuate.health.Status;
+
+/**
+ * A {@link SimpleStatusAggregator} implementation determining the overall health of an Axon Framework application using
+ * Axon Server. Adds the {@link HealthStatus#WARN} status to the regular set of {@link Status statuses}.
+ *
+ * @author Steven van Beelen
+ * @author Marc Gathier
+ * @since 4.6.0
+ */
+public class AxonServerStatusAggregator extends SimpleStatusAggregator {
+
+    /**
+     * Constructs a default Axon Server specific {@link SimpleStatusAggregator}. Adds the {@link HealthStatus#WARN}
+     * after {@link Status#OUT_OF_SERVICE} and before {@link Status#UP}.
+     */
+    public AxonServerStatusAggregator() {
+        super(Status.DOWN, Status.OUT_OF_SERVICE, HealthStatus.WARN, Status.UP, Status.UNKNOWN);
+    }
+}

spring-boot-autoconfigure/src/main/java/org/axonframework/springboot/autoconfig/AxonServerActuatorAutoConfiguration.java

@@ -16,7 +16,8 @@
 
 package org.axonframework.springboot.autoconfig;
 
-import org.axonframework.actuator.AxonServerHealthIndicator;
+import org.axonframework.actuator.axonserver.AxonServerHealthIndicator;
+import org.axonframework.actuator.axonserver.AxonServerStatusAggregator;
 import org.axonframework.axonserver.connector.AxonServerConnectionManager;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
@@ -41,4 +42,9 @@ public class AxonServerActuatorAutoConfiguration {
     public AxonServerHealthIndicator axonServerHealthIndicator(AxonServerConnectionManager connectionManager) {
         return new AxonServerHealthIndicator(connectionManager);
     }
+
+    @Bean
+    public AxonServerStatusAggregator axonServerStatusAggregator() {
+        return new AxonServerStatusAggregator();
+    }
 }

spring-boot-autoconfigure/src/test/java/org/axonframework/actuator/axonserver/AxonServerHealthIndicatorTest.java

@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2010-2022. Axon Framework
+ *
+ * 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 org.axonframework.actuator.axonserver;
+
+import org.axonframework.actuator.HealthStatus;
+import org.axonframework.axonserver.connector.AxonServerConnectionManager;
+import org.junit.jupiter.api.*;
+import org.springframework.boot.actuate.health.Health;
+import org.springframework.boot.actuate.health.Status;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+/**
+ * Test class validating the {@link AxonServerHealthIndicator}.
+ *
+ * @author Steven van Beelen
+ */
+class AxonServerHealthIndicatorTest {
+
+    private AxonServerConnectionManager connectionManager;
+
+    private AxonServerHealthIndicator testSubject;
+
+    @BeforeEach
+    void setUp() {
+        connectionManager = mock(AxonServerConnectionManager.class);
+        testSubject = new AxonServerHealthIndicator(connectionManager);
+    }
+
+    @Test
+    void testDoHealthCheckStatusReturnsUp() {
+        String testContextOne = "context-one";
+        String testContextTwo = "context-two";
+        String expectedDetailsContextOne = testContextOne + ".connection.active";
+        String expectedDetailsContextTwo = testContextTwo + ".connection.active";
+
+        Map<String, Boolean> testConnections = new HashMap<>();
+        testConnections.put(testContextOne, true);
+        testConnections.put(testContextTwo, true);
+        when(connectionManager.connections()).thenReturn(testConnections);
+
+        Health.Builder healthBuilder = new Health.Builder();
+
+        testSubject.doHealthCheck(healthBuilder);
+
+        Health result = healthBuilder.build();
+        assertEquals(Status.UP.getCode(), result.getStatus().getCode());
+
+        Map<String, Object> resultDetails = result.getDetails();
+        assertFalse(resultDetails.isEmpty());
+        assertEquals(2, resultDetails.size());
+        String detailsContextOne = (String) resultDetails.get(expectedDetailsContextOne);
+        assertNotNull(detailsContextOne);
+        assertEquals(Status.UP.getCode(), detailsContextOne);
+        String detailsContextTwo = (String) resultDetails.get(expectedDetailsContextTwo);
+        assertNotNull(detailsContextTwo);
+        assertEquals(Status.UP.getCode(), detailsContextTwo);
+    }
+
+    @Test
+    void testDoHealthCheckStatusReturnsWarning() {
+        String testContextOne = "context-one";
+        String testContextTwo = "context-two";
+        String expectedDetailsContextOne = testContextOne + ".connection.active";
+        String expectedDetailsContextTwo = testContextTwo + ".connection.active";
+
+        Map<String, Boolean> testConnections = new HashMap<>();
+        testConnections.put(testContextOne, true);
+        testConnections.put(testContextTwo, false);
+        when(connectionManager.connections()).thenReturn(testConnections);
+
+        Health.Builder healthBuilder = new Health.Builder();
+
+        testSubject.doHealthCheck(healthBuilder);
+
+        Health result = healthBuilder.build();
+        assertEquals(HealthStatus.WARN, result.getStatus());
+
+        Map<String, Object> resultDetails = result.getDetails();
+        assertFalse(resultDetails.isEmpty());
+        assertEquals(2, resultDetails.size());
+        String detailsContextOne = (String) resultDetails.get(expectedDetailsContextOne);
+        assertNotNull(detailsContextOne);
+        assertEquals(Status.UP.getCode(), detailsContextOne);
+        String detailsContextTwo = (String) resultDetails.get(expectedDetailsContextTwo);
+        assertNotNull(detailsContextTwo);
+        assertEquals(Status.DOWN.getCode(), detailsContextTwo);
+    }
+
+    @Test
+    void testDoHealthCheckStatusReturnsDown() {
+        String testContextOne = "context-one";
+        String testContextTwo = "context-two";
+        String expectedDetailsContextOne = testContextOne + ".connection.active";
+        String expectedDetailsContextTwo = testContextTwo + ".connection.active";
+
+        Map<String, Boolean> testConnections = new HashMap<>();
+        testConnections.put(testContextOne, false);
+        testConnections.put(testContextTwo, false);
+
+        when(connectionManager.connections()).thenReturn(testConnections);
+
+        Health.Builder healthBuilder = new Health.Builder();
+
+        testSubject.doHealthCheck(healthBuilder);
+
+        Health result = healthBuilder.build();
+        assertEquals(Status.DOWN.getCode(), result.getStatus().getCode());
+
+        Map<String, Object> resultDetails = result.getDetails();
+        assertFalse(resultDetails.isEmpty());
+        assertEquals(2, resultDetails.size());
+        String detailsContextOne = (String) resultDetails.get(expectedDetailsContextOne);
+        assertNotNull(detailsContextOne);
+        assertEquals(Status.DOWN.getCode(), detailsContextOne);
+        String detailsContextTwo = (String) resultDetails.get(expectedDetailsContextTwo);
+        assertNotNull(detailsContextTwo);
+        assertEquals(Status.DOWN.getCode(), detailsContextTwo);
+    }
+}

spring-boot-autoconfigure/src/test/java/org/axonframework/springboot/autoconfig/AxonServerActuatorAutoConfigurationTest.java

@@ -16,7 +16,8 @@
 
 package org.axonframework.springboot.autoconfig;
 
-import org.axonframework.actuator.AxonServerHealthIndicator;
+import org.axonframework.actuator.axonserver.AxonServerHealthIndicator;
+import org.axonframework.actuator.axonserver.AxonServerStatusAggregator;
 import org.junit.jupiter.api.*;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
@@ -44,14 +45,20 @@ void setUp() {
     void testAxonServerHealthIndicatorIsNotCreatedForAxonServerDisabled() {
         testApplicationContext.withUserConfiguration(TestContext.class)
                               .withPropertyValues("axon.axonserver.enabled:false")
-                              .run(context -> assertThat(context).doesNotHaveBean(AxonServerHealthIndicator.class));
+                              .run(context -> {
+                                  assertThat(context).doesNotHaveBean(AxonServerHealthIndicator.class);
+                                  assertThat(context).doesNotHaveBean(AxonServerStatusAggregator.class);
+                              });
     }
 
     @Test
     void testAxonServerHealthIndicatorIsCreated() {
         testApplicationContext.withUserConfiguration(TestContext.class)
                               .withPropertyValues("axon.axonserver.enabled:true")
-                              .run(context -> assertThat(context).hasSingleBean(AxonServerHealthIndicator.class));
+                              .run(context -> {
+                                  assertThat(context).hasSingleBean(AxonServerHealthIndicator.class);
+                                  assertThat(context).hasSingleBean(AxonServerStatusAggregator.class);
+                              });
     }
 
     @ContextConfiguration