[7.11] [ILM] check if delete phase has actions (#66664) (#67076)

* [ILM] check if delete phase has actions (#65847) (#66664)

Validate the delete phase to define actions.

(cherry picked from commit 7f39514)
Signed-off-by: Andrei Dan <andrei.dan@elastic.co>

* Test: fix testValidatePhases for delete phase (#67082)

The delete phase can no longer be defined as empty, it requires at least
one action to be defined. This fixes the test that used an empty collection
of actions for the delete phase to include the delete action.

(cherry picked from commit 8b158ad)
Signed-off-by: Andrei Dan <andrei.dan@elastic.co>

client/rest-high-level/src/main/java/org/elasticsearch/client/indexlifecycle/LifecyclePolicy.java

@@ -80,7 +80,10 @@ public LifecyclePolicy(String name, Map<String, Phase> phases) {
             if (ALLOWED_ACTIONS.containsKey(phase.getName()) == false) {
                 throw new IllegalArgumentException("Lifecycle does not support phase [" + phase.getName() + "]");
             }
-            phase.getActions().forEach((actionName, action) -> {
+           if (phase.getName().equals("delete") && phase.getActions().size() == 0) {
+              throw new IllegalArgumentException("phase [" + phase.getName() + "] must define actions");
+           }
+           phase.getActions().forEach((actionName, action) -> {
                 if (ALLOWED_ACTIONS.get(phase.getName()).contains(actionName) == false) {
                     throw new IllegalArgumentException("invalid action [" + actionName + "] " +
                         "defined in phase [" + phase.getName() +"]");

client/rest-high-level/src/test/java/org/elasticsearch/client/indexlifecycle/LifecyclePolicyTests.java

@@ -99,7 +99,8 @@ public void testValidatePhases() {
             phaseName += randomAlphaOfLength(5);
         }
         Map<String, Phase> phases = Collections.singletonMap(phaseName,
-            new Phase(phaseName, TimeValue.ZERO, Collections.emptyMap()));
+            new Phase(phaseName, TimeValue.ZERO, phaseName.equals("delete") ? Collections.singletonMap(DeleteAction.NAME,
+                new DeleteAction()) : Collections.emptyMap()));
         if (invalid) {
             Exception e = expectThrows(IllegalArgumentException.class, () -> new LifecyclePolicy(lifecycleName, phases));
             assertThat(e.getMessage(), equalTo("Lifecycle does not support phase [" + phaseName + "]"));
@@ -192,6 +193,17 @@ public void testValidateDeletePhase() {
         }
     }
 
+    public void testValidateEmptyDeletePhase() {
+        Map<String, LifecycleAction> actions = new HashMap<>();
+
+        Phase delete = new Phase("delete", TimeValue.ZERO, actions);
+        Map<String, Phase> phases = Collections.singletonMap("delete", delete);
+
+        Exception e = expectThrows(IllegalArgumentException.class,
+            () -> new LifecyclePolicy(lifecycleName, phases));
+        assertThat(e.getMessage(), equalTo("phase [" + delete.getName() + "] must define actions"));
+    }
+
     public static LifecyclePolicy createRandomPolicy(String lifecycleName) {
         List<String> phaseNames = randomSubsetOf(Arrays.asList("hot", "warm", "cold", "delete"));
         Map<String, Phase> phases = new HashMap<>(phaseNames.size());
@@ -208,6 +220,17 @@ public static LifecyclePolicy createRandomPolicy(String lifecycleName) {
                 default:
                     throw new IllegalArgumentException("invalid phase [" + phase + "]");
             }};
+        Function<String, Boolean> allowEmptyActions = (phase) -> {
+            switch (phase) {
+                case "hot":
+                case "warm":
+                case "cold":
+                    return true;
+                case "delete":
+                    return false;
+                default:
+                    throw new IllegalArgumentException("invalid phase [" + phase + "]");
+            }};
         Function<String, LifecycleAction> randomAction = (action) ->  {
             switch (action) {
                 case AllocateAction.NAME:
@@ -238,7 +261,12 @@ public static LifecyclePolicy createRandomPolicy(String lifecycleName) {
         for (String phase : phaseNames) {
             TimeValue after = TimeValue.parseTimeValue(randomTimeValue(0, 1000000000, "s", "m", "h", "d"), "test_after");
             Map<String, LifecycleAction> actions = new HashMap<>();
-            List<String> actionNames = randomSubsetOf(validActions.apply(phase));
+            List<String> actionNames;
+            if (allowEmptyActions.apply(phase)) {
+                actionNames = randomSubsetOf(validActions.apply(phase));
+            } else {
+                actionNames = randomSubsetOf(randomIntBetween(1, validActions.apply(phase).size()), validActions.apply(phase));
+            }
             for (String action : actionNames) {
                 actions.put(action, randomAction.apply(action));
             }