Fix deterministic trouble for custom watched services

We now only counts attacks on custom watched services instead of
counting all attacks.

Closes #451

Author: denniseffing

chaos-monkey-spring-boot/src/main/java/de/codecentric/spring/boot/chaos/monkey/component/ChaosMonkeyRequestScope.java

@@ -67,24 +67,11 @@ public ChaosMonkeyRequestScope(ChaosMonkeySettings chaosMonkeySettings, List<Cha
     }
 
     public void callChaosMonkey(ChaosTarget type, String simpleName) {
-        if (isEnabled(type, simpleName) && isTrouble()) {
-
+        if (isEnabled(type, simpleName) && isTrouble(simpleName)) {
             if (metricEventPublisher != null) {
                 metricEventPublisher.publishMetricEvent(MetricType.APPLICATION_REQ_COUNT, "type", "total");
             }
-
-            // Custom watched services can be defined at runtime, if there are any, only
-            // these will be attacked!
-            AssaultProperties assaultProps = chaosMonkeySettings.getAssaultProperties();
-            if (assaultProps.isWatchedCustomServicesActive()) {
-                if (assaultProps.getWatchedCustomServices().stream().anyMatch(simpleName::startsWith)) {
-                    // only all listed custom methods will be attacked
-                    chooseAndRunAttack();
-                }
-            } else {
-                // default attack if no custom watched service is defined
-                chooseAndRunAttack();
-            }
+            chooseAndRunAttack();
         }
     }
 
@@ -105,7 +92,14 @@ private ChaosMonkeyAssault getRandomFrom(List<ChaosMonkeyAssault> activeAssaults
         return activeAssaults.get(exceptionRand);
     }
 
-    private boolean isTrouble() {
+    private boolean isTrouble(String simpleName) {
+        // Custom watched services can be defined at runtime, if there are any, only
+        // these will be attacked!
+        AssaultProperties assaultProperties = chaosMonkeySettings.getAssaultProperties();
+        if (assaultProperties.isWatchedCustomServicesActive() && assaultProperties.getWatchedCustomServices().stream().noneMatch(simpleName::startsWith)) {
+            return false;
+        }
+
         if (chaosMonkeySettings.getAssaultProperties().isDeterministic()) {
             return assaultCounter.incrementAndGet() % chaosMonkeySettings.getAssaultProperties().getLevel() == 0;
         } else {

chaos-monkey-spring-boot/src/test/java/de/codecentric/spring/boot/chaos/monkey/component/ChaosMonkeyRequestScopeTest.java

@@ -198,6 +198,23 @@ void callChaosMonkey_givenDeterministicTrouble_shouldRunAttackAndPublishRequestC
         verify(metricEventPublisherMock).publishMetricEvent(MetricType.APPLICATION_REQ_COUNT, "type", "assaulted");
     }
 
+    @Test
+    void callChaosMonkey_givenDeterministicTroubleAndConfiguredWatchedCustomServices_shouldNotRunAttackIfAttackCountIsLowerThanLevel() {
+        givenChaosMonkeyIsEnabled();
+        givenOneActiveAttack();
+        given(assaultProperties.isDeterministic()).willReturn(true);
+        given(assaultProperties.getLevel()).willReturn(3);
+        given(assaultProperties.isWatchedCustomServicesActive()).willReturn(true);
+        given(assaultProperties.getWatchedCustomServices()).willReturn(List.of("de.test.CustomService.someMethod"));
+
+        // Important: We call chaos monkey three times, but the second attack is not on the watched custom service!
+        chaosMonkeyRequestScope.callChaosMonkey(null, "de.test.CustomService.someMethod");
+        chaosMonkeyRequestScope.callChaosMonkey(null, "de.test.CustomService.someOtherMethod");
+        chaosMonkeyRequestScope.callChaosMonkey(null, "de.test.CustomService.someMethod");
+
+        verify(assaults.get(0), never()).attack();
+    }
+
     @Test
     void callChaosMonkey_givenConfiguredWatchedCustomServices_shouldRunAttackIfTargetPackageNameMatches() {
         givenChaosMonkeyIsEnabled();