CCR: mention how to enable soft deletes in error message when not enabled (#36476)

Author: bleskes

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportPutFollowAction.java

@@ -124,9 +124,11 @@ private void createFollowerIndex(
             listener.onFailure(new IllegalArgumentException("leader index [" + request.getLeaderIndex() + "] does not exist"));
             return;
         }
-        if (leaderIndexMetaData.getSettings().getAsBoolean(IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey(), false) == false) {
+        if (IndexSettings.INDEX_SOFT_DELETES_SETTING.get(leaderIndexMetaData.getSettings()) == false) {
             listener.onFailure(
-                new IllegalArgumentException("leader index [" + request.getLeaderIndex() + "] does not have soft deletes enabled"));
+                new IllegalArgumentException("leader index [" + request.getLeaderIndex() + "] does not have soft deletes enabled. " +
+                    "soft deletes must be enabled when the index is created by setting " + IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey()
+                    + " to true"));
             return;
         }
 

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportResumeFollowAction.java

@@ -211,9 +211,10 @@ static void validate(
             }
         }
 
-        if (leaderIndex.getSettings().getAsBoolean(IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey(), false) == false) {
+        if (IndexSettings.INDEX_SOFT_DELETES_SETTING.get(leaderIndex.getSettings()) == false) {
             throw new IllegalArgumentException("leader index [" + leaderIndex.getIndex().getName() +
-                "] does not have soft deletes enabled");
+                "] does not have soft deletes enabled. soft deletes must be enabled when the index is created by setting "
+                + IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey() + " to true");
         }
         if (followIndex.getSettings().getAsBoolean(IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey(), false) == false) {
             throw new IllegalArgumentException("follower index [" + request.getFollowerIndex() + "] does not have soft deletes enabled");

x-pack/plugin/ccr/src/test/java/org/elasticsearch/xpack/ccr/LocalIndexFollowingIT.java

@@ -79,7 +79,9 @@ public void testDoNotCreateFollowerIfLeaderDoesNotHaveSoftDeletes() throws Excep
         putFollowRequest.setFollowRequest(followRequest);
         IllegalArgumentException error = expectThrows(IllegalArgumentException.class,
             () -> client().execute(PutFollowAction.INSTANCE, putFollowRequest).actionGet());
-        assertThat(error.getMessage(), equalTo("leader index [leader-index] does not have soft deletes enabled"));
+        assertThat(error.getMessage(), equalTo("leader index [leader-index] does not have soft deletes enabled. " +
+            "soft deletes must be enabled when the index is created by setting " + IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey()
+            + " to true"));
         assertThat(client().admin().indices().prepareExists("follower-index").get().isExists(), equalTo(false));
     }
 

x-pack/plugin/ccr/src/test/java/org/elasticsearch/xpack/ccr/action/TransportResumeFollowActionTests.java

@@ -76,7 +76,9 @@ public void testValidation() throws IOException {
             IndexMetaData leaderIMD = createIMD("index1", 5, Settings.EMPTY, null);
             IndexMetaData followIMD = createIMD("index2", 5, Settings.EMPTY, customMetaData);
             Exception e = expectThrows(IllegalArgumentException.class, () -> validate(request, leaderIMD, followIMD, UUIDs, null));
-            assertThat(e.getMessage(), equalTo("leader index [index1] does not have soft deletes enabled"));
+            assertThat(e.getMessage(), equalTo("leader index [index1] does not have soft deletes enabled. " +
+                "soft deletes must be enabled when the index is created by setting " + IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey()
+                + " to true"));
         }
         {
             // should fail because the follower index does not have soft deletes enabled