Forward-port late deprecation info API changes to 8.x (#83675) (#84318)

This is a forward-port of #82487, #83544, #83601, #84145, and #84246, but given that the branches had diverged so much they were not a straightforward cherry-picks. It required modifying the interface of the NodeDeprecationChecks to include ClusterState as we do in 7.x.

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/deprecation/DeprecationIssue.java

@@ -15,15 +15,26 @@
 import org.elasticsearch.xcontent.XContentBuilder;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
+import java.util.stream.Collectors;
 
 /**
  * Information about deprecated items
  */
 public class DeprecationIssue implements Writeable, ToXContentObject {
 
+    private static final String ACTIONS_META_FIELD = "actions";
+    private static final String OBJECTS_FIELD = "objects";
+    private static final String ACTION_TYPE = "action_type";
+    private static final String REMOVE_SETTINGS_ACTION_TYPE = "remove_settings";
+
     public enum Level implements Writeable {
         /**
          * Resolving this issue is advised but not required to upgrade. There may be undesired changes in behavior unless this issue is
@@ -121,6 +132,10 @@ public Map<String, Object> getMeta() {
         return meta;
     }
 
+    private Optional<Meta> getMetaObject() {
+        return Meta.fromMetaMap(meta);
+    }
+
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         level.writeTo(out);
@@ -170,4 +185,233 @@ public int hashCode() {
     public String toString() {
         return Strings.toString(this);
     }
+
+    public static Map<String, Object> createMetaMapForRemovableSettings(List<String> removableSettings) {
+        return Meta.fromRemovableSettings(removableSettings).toMetaMap();
+    }
+
+    /**
+     * This method returns a DeprecationIssue that has in its meta object the intersection of all auto-removable settings that appear on
+     * all of the DeprecationIssues that are passed in. This method assumes that all DeprecationIssues passed in are equal, except for the
+     * auto-removable settings in the meta object.
+     * @param similarIssues DeprecationIssues that are assumed to be identical except possibly removal actions.
+     * @return A DeprecationIssue containing only the removal actions that are in all similarIssues
+     */
+    public static DeprecationIssue getIntersectionOfRemovableSettings(List<DeprecationIssue> similarIssues) {
+        if (similarIssues == null || similarIssues.isEmpty()) {
+            return null;
+        }
+        if (similarIssues.size() == 1) {
+            return similarIssues.get(0);
+        }
+        DeprecationIssue representativeIssue = similarIssues.get(0);
+        Optional<Meta> metaIntersection = similarIssues.stream()
+            .map(DeprecationIssue::getMetaObject)
+            .reduce(
+                representativeIssue.getMetaObject(),
+                (intersectionSoFar, meta) -> intersectionSoFar.isPresent() && meta.isPresent()
+                    ? Optional.of(intersectionSoFar.get().getIntersection(meta.get()))
+                    : Optional.empty()
+            );
+        return new DeprecationIssue(
+            representativeIssue.level,
+            representativeIssue.message,
+            representativeIssue.url,
+            representativeIssue.details,
+            representativeIssue.resolveDuringRollingUpgrade,
+            metaIntersection.map(Meta::toMetaMap).orElse(null)
+        );
+    }
+
+    /*
+     * This class a represents a DeprecationIssue's meta map. A meta map might look something like:
+     * {
+     *    "_meta":{
+     *       "foo": "bar",
+     *       "actions":[
+     *          {
+     *             "action_type":"remove_settings",
+     *             "objects":[
+     *                "setting1",
+     *                "setting2"
+     *             ]
+     *          }
+     *       ]
+     *    }
+     * }
+     */
+    private static final class Meta {
+        private final List<Action> actions;
+        private final Map<String, Object> nonActionMetadata;
+
+        Meta(List<Action> actions, Map<String, Object> nonActionMetadata) {
+            this.actions = actions;
+            this.nonActionMetadata = nonActionMetadata;
+        }
+
+        private static Meta fromRemovableSettings(List<String> removableSettings) {
+            List<Action> actions;
+            if (removableSettings == null) {
+                actions = null;
+            } else {
+                actions = Collections.singletonList(new RemovalAction(removableSettings));
+            }
+            return new Meta(actions, Collections.emptyMap());
+        }
+
+        private Map<String, Object> toMetaMap() {
+            Map<String, Object> metaMap;
+            if (actions != null) {
+                metaMap = new HashMap<>(nonActionMetadata);
+                List<Map<String, Object>> actionsList = actions.stream().map(Action::toActionMap).collect(Collectors.toList());
+                if (actionsList.isEmpty() == false) {
+                    metaMap.put(ACTIONS_META_FIELD, actionsList);
+                }
+            } else {
+                metaMap = nonActionMetadata;
+            }
+            return metaMap;
+        }
+
+        /*
+         * This method gets the intersection of this Meta with another. It assumes that the Meta objects are identical, except possibly the
+         * contents of the removal actions. So the interection is a new Meta object with only the removal actions that appear in both.
+         */
+        private Meta getIntersection(Meta another) {
+            final List<Action> actionsIntersection;
+            if (actions != null && another.actions != null) {
+                List<Action> combinedActions = this.actions.stream()
+                    .filter(action -> action instanceof RemovalAction == false)
+                    .collect(Collectors.toList());
+                Optional<Action> thisRemovalAction = this.actions.stream().filter(action -> action instanceof RemovalAction).findFirst();
+                Optional<Action> otherRemovalAction = another.actions.stream()
+                    .filter(action -> action instanceof RemovalAction)
+                    .findFirst();
+                if (thisRemovalAction.isPresent() && otherRemovalAction.isPresent()) {
+                    Optional<List<String>> removableSettingsOptional = ((RemovalAction) thisRemovalAction.get()).getRemovableSettings();
+                    List<String> removableSettings = removableSettingsOptional.map(
+                        settings -> settings.stream()
+                            .distinct()
+                            .filter(
+                                setting -> ((RemovalAction) otherRemovalAction.get()).getRemovableSettings()
+                                    .map(list -> list.contains(setting))
+                                    .orElse(false)
+                            )
+                            .collect(Collectors.toList())
+                    ).orElse(Collections.emptyList());
+                    if (removableSettings.isEmpty() == false) {
+                        combinedActions.add(new RemovalAction(removableSettings));
+                    }
+                }
+                actionsIntersection = combinedActions;
+            } else {
+                actionsIntersection = null;
+            }
+            return new Meta(actionsIntersection, nonActionMetadata);
+        }
+
+        /*
+         * Returns an Optional Meta object from a DeprecationIssue's meta Map. If the meta Map is null then the Optional will not be
+         * present.
+         */
+        @SuppressWarnings("unchecked")
+        private static Optional<Meta> fromMetaMap(Map<String, Object> metaMap) {
+            if (metaMap == null) {
+                return Optional.empty();
+            }
+            List<Map<String, Object>> actionMaps = (List<Map<String, Object>>) metaMap.get(ACTIONS_META_FIELD);
+            List<Action> actions;
+            if (actionMaps == null) {
+                actions = null;
+            } else {
+                actions = new ArrayList<>();
+                for (Map<String, Object> actionMap : actionMaps) {
+                    final Action action;
+                    if (REMOVE_SETTINGS_ACTION_TYPE.equals(actionMap.get(ACTION_TYPE))) {
+                        action = RemovalAction.fromActionMap(actionMap);
+                    } else {
+                        action = UnknownAction.fromActionMap(actionMap);
+                    }
+                    actions.add(action);
+                }
+            }
+            Map<String, Object> nonActionMap = metaMap.entrySet()
+                .stream()
+                .filter(entry -> entry.getKey().equals(ACTIONS_META_FIELD) == false)
+                .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
+
+            Meta meta = new Meta(actions, nonActionMap);
+            return Optional.of(meta);
+        }
+    }
+
+    /*
+     * A DeprecationIssue's meta Map optionally has an array of actions. This class reprenents one of the items in that array.
+     */
+    private interface Action {
+        /*
+         * This method creates the Map that goes inside the actions list for this Action in a meta Map.
+         */
+        Map<String, Object> toActionMap();
+    }
+
+    /*
+     * This class a represents remove_settings action within the actions list in a meta Map.
+     */
+    private static final class RemovalAction implements Action {
+        private final List<String> removableSettings;
+
+        RemovalAction(List<String> removableSettings) {
+            this.removableSettings = removableSettings;
+        }
+
+        @SuppressWarnings("unchecked")
+        private static RemovalAction fromActionMap(Map<String, Object> actionMap) {
+            final List<String> removableSettings;
+            Object removableSettingsObject = actionMap.get(OBJECTS_FIELD);
+            if (removableSettingsObject == null) {
+                removableSettings = null;
+            } else {
+                removableSettings = (List<String>) removableSettingsObject;
+            }
+            return new RemovalAction(removableSettings);
+        }
+
+        private Optional<List<String>> getRemovableSettings() {
+            return removableSettings == null ? Optional.empty() : Optional.of(removableSettings);
+        }
+
+        @Override
+        public Map<String, Object> toActionMap() {
+            final Map<String, Object> actionMap;
+            if (removableSettings != null) {
+                actionMap = new HashMap<>();
+                actionMap.put(OBJECTS_FIELD, removableSettings);
+                actionMap.put(ACTION_TYPE, REMOVE_SETTINGS_ACTION_TYPE);
+            } else {
+                actionMap = null;
+            }
+            return actionMap;
+        }
+    }
+
+    /*
+     * This represents an action within the actions list in a meta Map that is *not* a removal_action.
+     */
+    private static class UnknownAction implements Action {
+        private final Map<String, Object> actionMap;
+
+        private UnknownAction(Map<String, Object> actionMap) {
+            this.actionMap = actionMap;
+        }
+
+        private static Action fromActionMap(Map<String, Object> actionMap) {
+            return new UnknownAction(actionMap);
+        }
+
+        @Override
+        public Map<String, Object> toActionMap() {
+            return actionMap;
+        }
+    }
 }

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/deprecation/DeprecationIssueTests.java

@@ -18,6 +18,9 @@
 import org.junit.Before;
 
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.Map;
 
 import static org.elasticsearch.xcontent.ToXContent.EMPTY_PARAMS;
@@ -83,4 +86,58 @@ public void testToXContent() throws IOException {
         DeprecationIssue other = new DeprecationIssue(Level.fromString(level), message, url, details, requiresRestart, meta);
         assertThat(issue, equalTo(other));
     }
+
+    public void testGetIntersectionOfRemovableSettings() {
+        assertNull(DeprecationIssue.getIntersectionOfRemovableSettings(null));
+        assertNull(DeprecationIssue.getIntersectionOfRemovableSettings(Collections.emptyList()));
+        Map<String, Object> randomMeta = randomMap(1, 5, () -> Tuple.tuple(randomAlphaOfLength(4), randomAlphaOfLength(4)));
+        DeprecationIssue issue1 = createTestDeprecationIssue(getTestMetaMap(randomMeta, "setting.1", "setting.2", "setting.3"));
+        assertEquals(issue1, DeprecationIssue.getIntersectionOfRemovableSettings(Collections.singletonList(issue1)));
+        DeprecationIssue issue2 = createTestDeprecationIssue(issue1, getTestMetaMap(randomMeta, "setting.2"));
+        assertNotEquals(issue1, issue2);
+        assertEquals(issue2, DeprecationIssue.getIntersectionOfRemovableSettings(Arrays.asList(issue1, issue2)));
+        DeprecationIssue issue3 = createTestDeprecationIssue(issue1, getTestMetaMap(randomMeta, "setting.2", "setting.4"));
+        assertEquals(issue2, DeprecationIssue.getIntersectionOfRemovableSettings(Arrays.asList(issue1, issue2, issue3)));
+        DeprecationIssue issue4 = createTestDeprecationIssue(issue1, getTestMetaMap(randomMeta, "setting.5"));
+        DeprecationIssue emptySettingsIssue = createTestDeprecationIssue(issue1, getTestMetaMap(randomMeta));
+        assertEquals(
+            emptySettingsIssue,
+            DeprecationIssue.getIntersectionOfRemovableSettings(Arrays.asList(issue1, issue2, issue3, issue4))
+        );
+        DeprecationIssue issue5 = createTestDeprecationIssue(getTestMetaMap(randomMeta, "setting.1", "setting.2", "setting.3"));
+        assertEquals(issue1, DeprecationIssue.getIntersectionOfRemovableSettings(Arrays.asList(issue1, issue5)));
+    }
+
+    private static Map<String, Object> getTestMetaMap(Map<String, Object> baseMap, String... settings) {
+        Map<String, Object> metaMap = new HashMap<>();
+        Map<String, Object> settingsMetaMap = DeprecationIssue.createMetaMapForRemovableSettings(
+            settings.length == 0 ? null : Arrays.asList(settings)
+        );
+        metaMap.putAll(settingsMetaMap);
+        metaMap.putAll(baseMap);
+        return metaMap;
+    }
+
+    private static DeprecationIssue createTestDeprecationIssue(Map<String, Object> metaMap) {
+        String details = randomBoolean() ? randomAlphaOfLength(10) : null;
+        return new DeprecationIssue(
+            randomFrom(DeprecationIssue.Level.values()),
+            randomAlphaOfLength(10),
+            randomAlphaOfLength(10),
+            details,
+            randomBoolean(),
+            metaMap
+        );
+    }
+
+    private static DeprecationIssue createTestDeprecationIssue(DeprecationIssue seedIssue, Map<String, Object> metaMap) {
+        return new DeprecationIssue(
+            seedIssue.getLevel(),
+            seedIssue.getMessage(),
+            seedIssue.getUrl(),
+            seedIssue.getDetails(),
+            seedIssue.isResolveDuringRollingUpgrade(),
+            metaMap
+        );
+    }
 }