Add targetIndexSettings validation with test

Signed-off-by: Aleksandr Tuliakov <[email protected]>

Author: MrChaos1993

src/main/kotlin/org/opensearch/indexmanagement/rollup/model/Rollup.kt

@@ -5,6 +5,7 @@
 
 package org.opensearch.indexmanagement.rollup.model
 
+import org.opensearch.common.settings.IndexScopedSettings
 import org.opensearch.common.settings.Settings
 import org.opensearch.commons.authuser.User
 import org.opensearch.core.common.io.stream.StreamInput
@@ -89,6 +90,9 @@ data class Rollup(
             }
         }
         require(sourceIndex != targetIndex) { "Your source and target index cannot be the same" }
+        if (targetIndexSettings != null) {
+            IndexScopedSettings(null, IndexScopedSettings.BUILT_IN_INDEX_SETTINGS).validate(targetIndexSettings, true)
+        }
         require(dimensions.filter { it.type == Dimension.Type.DATE_HISTOGRAM }.size == 1) {
             "Must specify precisely one date histogram dimension" // this covers empty dimensions case too
         }

src/test/kotlin/org/opensearch/indexmanagement/rollup/model/RollupTests.kt

@@ -5,6 +5,8 @@
 
 package org.opensearch.indexmanagement.rollup.model
 
+import org.opensearch.common.settings.Settings
+import org.opensearch.common.settings.SettingsException
 import org.opensearch.indexmanagement.randomInstant
 import org.opensearch.indexmanagement.randomSchedule
 import org.opensearch.indexmanagement.rollup.randomDateHistogram
@@ -52,6 +54,16 @@ class RollupTests : OpenSearchTestCase() {
         }
     }
 
+    fun `test rollup requires correct target index settings`() {
+        assertFailsWith(SettingsException::class, "Unknown property was `index.codec1`") {
+            randomRollup().copy(targetIndexSettings = Settings.builder().put("index.codec1", "zlib").build())
+        }
+
+        val sb = Settings.builder()
+        sb.put("index.codec", "zlib")
+        randomRollup().copy(targetIndexSettings = sb.build())
+    }
+
     fun `test rollup requires page size to be between 1 and 10k`() {
         assertFailsWith(IllegalArgumentException::class, "Page size was negative") {
             randomRollup().copy(pageSize = -1)