Fix /chaosmonkey/assaults/runtime/attack not responding when executing kill application assault (#528)

Author: jens-kaiser

chaos-monkey-docs/src/main/asciidoc/changes.adoc

@@ -5,6 +5,7 @@ Built with Spring Boot {spring-boot-version}
 
 === Bug Fixes
 // - https://github.com/codecentric/chaos-monkey-spring-boot/pull/xxx[#xxx] Added example entry. Please don't remove.
+- https://github.com/codecentric/chaos-monkey-spring-boot/pull/528[#528] Fix `/chaosmonkey/assaults/runtime/attack` not responding when executing kill application assault
 
 === Improvements
 // - https://github.com/codecentric/chaos-monkey-spring-boot/pull/xxx[#xxx] Added example entry. Please don't remove.

chaos-monkey-spring-boot/pom.xml

@@ -124,12 +124,6 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
-            <exclusions>
-                <exclusion>
-                    <groupId>org.hamcrest</groupId>
-                    <artifactId>hamcrest</artifactId>
-                </exclusion>
-            </exclusions>
         </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>

chaos-monkey-spring-boot/src/main/java/de/codecentric/spring/boot/chaos/monkey/assaults/KillAppAssault.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2023 the original author or authors.
+ * Copyright 2018-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,27 +19,34 @@
 import de.codecentric.spring.boot.chaos.monkey.component.MetricType;
 import de.codecentric.spring.boot.chaos.monkey.configuration.AssaultProperties;
 import de.codecentric.spring.boot.chaos.monkey.configuration.ChaosMonkeySettings;
-import java.util.concurrent.TimeUnit;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.boot.SpringApplication;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
+import org.springframework.lang.NonNull;
 
-/** @author Thorsten Deelmann */
-public class KillAppAssault implements ChaosMonkeyRuntimeAssault, ApplicationContextAware {
-
-    private static final Logger Logger = LoggerFactory.getLogger(KillAppAssault.class);
+import java.util.concurrent.TimeUnit;
 
-    private final ChaosMonkeySettings settings;
+/**
+ * @author Thorsten Deelmann, Dennis Effing
+ */
+public class KillAppAssault implements ChaosMonkeyRuntimeAssault {
 
-    private ApplicationContext context;
+    private static final Logger Logger = LoggerFactory.getLogger(KillAppAssault.class);
 
     private final MetricEventPublisher metricEventPublisher;
+    private final ChaosMonkeySettings settings;
+    private final ExitHelper exitHelper;
 
     public KillAppAssault(ChaosMonkeySettings settings, MetricEventPublisher metricEventPublisher) {
+        this(settings, metricEventPublisher, new ExitHelper());
+    }
+
+    public KillAppAssault(ChaosMonkeySettings settings, MetricEventPublisher metricEventPublisher, ExitHelper exitHelper) {
         this.settings = settings;
         this.metricEventPublisher = metricEventPublisher;
+        this.exitHelper = exitHelper;
     }
 
     @Override
@@ -56,32 +63,50 @@ public void attack() {
                 metricEventPublisher.publishMetricEvent(MetricType.KILLAPP_ASSAULT);
             }
 
-            int exit = SpringApplication.exit(context, () -> 0);
-
-            long remaining = 5000;
-            long end = System.currentTimeMillis() + remaining;
-            while (true) {
-                try {
-                    TimeUnit.MILLISECONDS.sleep(remaining); // wait before kill to deliver some metrics
-                    break;
-                } catch (InterruptedException ignored) {
-                    remaining = end - System.currentTimeMillis();
-                }
-            }
-
-            System.exit(exit);
+            Thread thread = new Thread(this::killApplication);
+            thread.setContextClassLoader(this.getClass().getClassLoader());
+            thread.start();
         } catch (Exception e) {
             Logger.info("Chaos Monkey - Unable to kill the App, I am not the BOSS!");
         }
     }
 
-    @Override
-    public void setApplicationContext(ApplicationContext applicationContext) {
-        this.context = applicationContext;
+    private void killApplication() {
+        int exitCode = exitHelper.exitSpringApplication(0);
+
+        long remaining = 5000;
+        long end = System.currentTimeMillis() + remaining;
+        while (true) {
+            try {
+                TimeUnit.MILLISECONDS.sleep(remaining); // wait before kill to deliver some metrics
+                break;
+            } catch (InterruptedException ignored) {
+                remaining = end - System.currentTimeMillis();
+            }
+        }
+
+        exitHelper.exitJvm(exitCode);
     }
 
     @Override
     public String getCronExpression(AssaultProperties assaultProperties) {
         return assaultProperties.getKillApplicationCronExpression();
     }
+
+    public static class ExitHelper implements ApplicationContextAware {
+        private ApplicationContext context;
+
+        public int exitSpringApplication(int code) {
+            return SpringApplication.exit(context, () -> code);
+        }
+
+        public void exitJvm(int code) {
+            System.exit(code);
+        }
+
+        @Override
+        public void setApplicationContext(@NonNull ApplicationContext context) {
+            this.context = context;
+        }
+    }
 }

chaos-monkey-spring-boot/src/main/java/de/codecentric/spring/boot/chaos/monkey/configuration/ChaosMonkeyConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2023 the original author or authors.
+ * Copyright 2018-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -109,8 +109,14 @@ public ExceptionAssault exceptionAssault(ChaosMonkeySettings settings, MetricEve
 
     @Bean
     @ConditionalOnMissingBean
-    public KillAppAssault killAppAssault(ChaosMonkeySettings settings, MetricEventPublisher publisher) {
-        return new KillAppAssault(settings, publisher);
+    public KillAppAssault killAppAssault(ChaosMonkeySettings settings, MetricEventPublisher publisher, KillAppAssault.ExitHelper exitHelper) {
+        return new KillAppAssault(settings, publisher, exitHelper);
+    }
+
+    @Bean
+    @ConditionalOnMissingBean
+    public KillAppAssault.ExitHelper exitHelper() {
+        return new KillAppAssault.ExitHelper();
     }
 
     @Bean

chaos-monkey-spring-boot/src/test/java/de/codecentric/spring/boot/chaos/monkey/assaults/KillAppAssaultIntegrationTest.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2018-2025 the original author or authors.
+ *
+ * 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
+ *
+ *     https://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 de.codecentric.spring.boot.chaos.monkey.assaults;
+
+import de.codecentric.spring.boot.demo.chaos.monkey.ChaosDemoApplication;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+
+import static org.awaitility.Awaitility.await;
+import static org.mockito.Mockito.verify;
+
+/**
+ * @author Thorsten Deelmann, Dennis Effing
+ */
+@SpringBootTest(classes = ChaosDemoApplication.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT, properties = {
+        "chaos.monkey.assaults.kill-application-active=true", "spring.profiles.active=chaos-monkey"})
+class KillAppAssaultIntegrationTest {
+
+    @Autowired
+    private KillAppAssault subject;
+
+    @MockitoBean
+    private KillAppAssault.ExitHelper exitHelper;
+
+    @Test
+    @DirtiesContext
+    void killsSpringBootApplication() {
+        subject.attack();
+
+        await().untilAsserted(() -> verify(exitHelper).exitJvm(0));
+    }
+}

chaos-monkey-spring-boot/src/test/java/de/codecentric/spring/boot/chaos/monkey/assaults/KillAppAssaultTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2024 the original author or authors.
+ * Copyright 2018-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,7 +18,12 @@
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import de.codecentric.spring.boot.chaos.monkey.configuration.*;
+import de.codecentric.spring.boot.chaos.monkey.assaults.KillAppAssault;
+import de.codecentric.spring.boot.chaos.monkey.configuration.AssaultException;
+import de.codecentric.spring.boot.chaos.monkey.configuration.AssaultProperties;
+import de.codecentric.spring.boot.chaos.monkey.configuration.ChaosMonkeyProperties;
+import de.codecentric.spring.boot.chaos.monkey.configuration.ChaosMonkeySettings;
+import de.codecentric.spring.boot.chaos.monkey.configuration.WatcherProperties;
 import de.codecentric.spring.boot.chaos.monkey.endpoints.dto.AssaultPropertiesUpdate;
 import de.codecentric.spring.boot.chaos.monkey.endpoints.dto.ChaosMonkeyStatusResponseDto;
 import de.codecentric.spring.boot.chaos.monkey.endpoints.dto.WatcherPropertiesUpdate;
@@ -31,8 +36,14 @@
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.web.client.TestRestTemplate;
 import org.springframework.boot.test.web.server.LocalServerPort;
-import org.springframework.http.*;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.TestPropertySource;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
 
 import java.time.OffsetDateTime;
 import java.util.Collections;
@@ -46,14 +57,19 @@
 @SpringBootTest(classes = ChaosDemoApplication.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
 @TestPropertySource("classpath:application-test-chaos-monkey-profile.properties")
 class ChaosMonkeyRequestScopeRestEndpointIntegrationTest {
+
+    private final ObjectMapper objectMapper = new ObjectMapper();
+
+    // NB: We don't want to kill the JVM the tests are running in
+    @MockitoBean
+    private KillAppAssault.ExitHelper exitHelper;
+
     @Autowired
     private ChaosMonkeySettings chaosMonkeySettings;
 
     @Autowired
     private TestRestTemplate testRestTemplate;
 
-    private final ObjectMapper objectMapper = new ObjectMapper();
-
     private String baseUrl;
 
     @BeforeEach
@@ -293,6 +309,16 @@ void postToDisableAfterEnableChaosMonkey() {
         assertThat(Objects.requireNonNull(result.getBody()).getDisabledAt()).isAfterOrEqualTo(disabledAt);
     }
 
+    @Test
+    void postToAttackRespondsIfKillAppAssaultIsConfigured() {
+        chaosMonkeySettings.getChaosMonkeyProperties().setEnabled(true);
+        chaosMonkeySettings.getAssaultProperties().setKillApplicationActive(true);
+
+        ResponseEntity<String> result = testRestTemplate.postForEntity(baseUrl + "/assaults/runtime/attack", null, String.class);
+        assertThat(result.getStatusCode()).isEqualTo(HttpStatus.OK);
+        assertThat(result.getBody()).isEqualTo("Started runtime assaults");
+    }
+
     private ResponseEntity<String> postChaosMonkeySettings(ChaosMonkeySettings chaosMonkeySettings) {
 
         return this.testRestTemplate.postForEntity(baseUrl, chaosMonkeySettings, String.class);