Backport Issue opensearch-project#998 (opensearch-project#1067)

* Backport issue opensearch-project#998 to 2.x Signed-off-by: Joshua Au <[email protected]> * Issue651 tests (opensearch-project#1046) * Implemented filtering on the ISM eplain API Signed-off-by: Joshua Au <[email protected]> * Fixed tests for ExplainRequest Signed-off-by: Joshua Au <[email protected]> * Added filtering on query and metadata map Signed-off-by: Joshua Au <[email protected]> * Filtered on indexNames in metadata Signed-off-by: Joshua Au <[email protected]> * Fixed github workflow check errors Signed-off-by: Joshua Au <[email protected]> * Removed debugging comments Signed-off-by: Joshua Au <[email protected]> * Updated code styling to make more clear Signed-off-by: Joshua Au <[email protected]> * Refactored code to match suggestions Signed-off-by: Joshua Au <[email protected]> * Added test case for the ExplainFilter.byMetaData and parse methods Signed-off-by: Joshua Au <[email protected]> * Started implementation of explain filter IT Signed-off-by: Joshua Au <[email protected]> * Implemented test explain filter method Signed-off-by: Joshua Au <[email protected]> * Implemented explain filter test on failure Signed-off-by: Joshua Au <[email protected]> * Cleaned up log statements Signed-off-by: Joshua Au <[email protected]> * Added explain filter test for success Signed-off-by: Joshua Au <[email protected]> * Fixed lint errors Signed-off-by: Joshua Au <[email protected]> * Removed policy from index to fix flaky tests Signed-off-by: Joshua Au <[email protected]> --------- Signed-off-by: Joshua Au <[email protected]> Signed-off-by: bowenlan-amzn <[email protected]> Co-authored-by: bowenlan-amzn <[email protected]> * Fixed content type import Signed-off-by: Joshua Au <[email protected]> * Implemented filtering on the ISM eplain API (opensearch-project#998) * Implemented filtering on the ISM eplain API Signed-off-by: Joshua Au <[email protected]> * Fixed tests for ExplainRequest Signed-off-by: Joshua Au <[email protected]> * Added filtering on query and metadata map Signed-off-by: Joshua Au <[email protected]> * Filtered on indexNames in metadata Signed-off-by: Joshua Au <[email protected]> * Fixed github workflow check errors Signed-off-by: Joshua Au <[email protected]> * Removed debugging comments Signed-off-by: Joshua Au <[email protected]> * Updated code styling to make more clear Signed-off-by: Joshua Au <[email protected]> * Refactored code to match suggestions Signed-off-by: Joshua Au <[email protected]> --------- Signed-off-by: Joshua Au <[email protected]> Co-authored-by: bowenlan-amzn <[email protected]> * Issue651 tests (opensearch-project#1046) * Implemented filtering on the ISM eplain API Signed-off-by: Joshua Au <[email protected]> * Fixed tests for ExplainRequest Signed-off-by: Joshua Au <[email protected]> * Added filtering on query and metadata map Signed-off-by: Joshua Au <[email protected]> * Filtered on indexNames in metadata Signed-off-by: Joshua Au <[email protected]> * Fixed github workflow check errors Signed-off-by: Joshua Au <[email protected]> * Removed debugging comments Signed-off-by: Joshua Au <[email protected]> * Updated code styling to make more clear Signed-off-by: Joshua Au <[email protected]> * Refactored code to match suggestions Signed-off-by: Joshua Au <[email protected]> * Added test case for the ExplainFilter.byMetaData and parse methods Signed-off-by: Joshua Au <[email protected]> * Started implementation of explain filter IT Signed-off-by: Joshua Au <[email protected]> * Implemented test explain filter method Signed-off-by: Joshua Au <[email protected]> * Implemented explain filter test on failure Signed-off-by: Joshua Au <[email protected]> * Cleaned up log statements Signed-off-by: Joshua Au <[email protected]> * Added explain filter test for success Signed-off-by: Joshua Au <[email protected]> * Fixed lint errors Signed-off-by: Joshua Au <[email protected]> * Removed policy from index to fix flaky tests Signed-off-by: Joshua Au <[email protected]> --------- Signed-off-by: Joshua Au <[email protected]> Signed-off-by: bowenlan-amzn <[email protected]> Co-authored-by: bowenlan-amzn <[email protected]> * Backport explain filter tests * Sleep thread to allow jobs to finish Signed-off-by: Joshua Au <[email protected]> --------- Signed-off-by: Joshua Au <[email protected]> Signed-off-by: bowenlan-amzn <[email protected]> Co-authored-by: bowenlan-amzn <[email protected]>
reta · Jan 4, 2024 · d65545a · d65545a
1 parent e5997e8
commit d65545a
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Showing 12 changed files with 536 additions and 24 deletions.
diff --git a/src/main/kotlin/org/opensearch/indexmanagement/indexstatemanagement/model/ExplainFilter.kt b/src/main/kotlin/org/opensearch/indexmanagement/indexstatemanagement/model/ExplainFilter.kt
@@ -0,0 +1,131 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.indexmanagement.indexstatemanagement.model
+
+import org.opensearch.core.common.io.stream.StreamInput
+import org.opensearch.core.common.io.stream.StreamOutput
+import org.opensearch.core.common.io.stream.Writeable
+import org.opensearch.core.xcontent.ToXContent
+import org.opensearch.core.xcontent.ToXContentObject
+import org.opensearch.core.xcontent.XContentBuilder
+import org.opensearch.core.xcontent.XContentParser
+import org.opensearch.core.xcontent.XContentParser.Token
+import org.opensearch.core.xcontent.XContentParserUtils.ensureExpectedToken
+import org.opensearch.index.query.BoolQueryBuilder
+import org.opensearch.index.query.QueryBuilders
+import org.opensearch.indexmanagement.indexstatemanagement.util.MANAGED_INDEX_POLICY_ID_FIELD
+import org.opensearch.indexmanagement.spi.indexstatemanagement.model.ManagedIndexMetaData
+import java.io.IOException
+
+data class ExplainFilter(
+    val policyID: String? = null,
+    val state: String? = null,
+    val actionType: String? = null,
+    val failed: Boolean? = null
+) : ToXContentObject, Writeable {
+
+    @Throws(IOException::class)
+    constructor(sin: StreamInput) : this(
+        policyID = sin.readOptionalString(),
+        state = sin.readOptionalString(),
+        actionType = sin.readOptionalString(),
+        failed = sin.readOptionalBoolean()
+    )
+
+    override fun toXContent(builder: XContentBuilder, params: ToXContent.Params): XContentBuilder {
+        builder.startObject()
+        builder.startObject(FILTER_FIELD)
+
+        if (policyID != null) builder.field(POLICY_ID_FIELD, policyID)
+        if (state != null) builder.field(STATE_FIELD, state)
+        if (actionType != null) builder.field(ACTION_FIELD, actionType)
+        if (failed != null) builder.field(FAILED_FIELD, failed)
+
+        builder.endObject()
+        return builder.endObject()
+    }
+
+    @Throws(IOException::class)
+    override fun writeTo(out: StreamOutput) {
+        out.writeOptionalString(policyID)
+        out.writeOptionalString(state)
+        out.writeOptionalString(actionType)
+        out.writeOptionalBoolean(failed)
+    }
+
+    fun byMetaData(metaData: ManagedIndexMetaData): Boolean {
+        var isValid = true
+
+        val stateMetaData = metaData.stateMetaData
+        if (state != null && (stateMetaData == null || stateMetaData.name != state)) {
+            isValid = false
+        }
+
+        val actionMetaData = metaData.actionMetaData
+        if (actionType != null && (actionMetaData == null || actionMetaData.name != actionType)) {
+            isValid = false
+        }
+
+        val retryInfoMetaData = metaData.policyRetryInfo
+        val actionFailedNotValid = actionMetaData == null || actionMetaData.failed != failed
+        val retryFailedNotValid = retryInfoMetaData == null || retryInfoMetaData.failed != failed
+        if (failed != null && actionFailedNotValid && retryFailedNotValid) {
+            isValid = false
+        }
+
+        return isValid
+    }
+
+    companion object {
+        const val FILTER_FIELD = "filter"
+        const val POLICY_ID_FIELD = "policy_id"
+        const val STATE_FIELD = "state"
+        const val ACTION_FIELD = "action_type"
+        const val FAILED_FIELD = "failed"
+
+        @JvmStatic
+        @Throws(IOException::class)
+        fun parse(xcp: XContentParser): ExplainFilter {
+            var policyID: String? = null
+            var state: String? = null
+            var actionType: String? = null
+            var failed: Boolean? = null
+
+            ensureExpectedToken(Token.START_OBJECT, xcp.currentToken(), xcp)
+            while (xcp.nextToken() != Token.END_OBJECT) {
+                val fieldName = xcp.currentName()
+                xcp.nextToken()
+
+                when (fieldName) {
+                    FILTER_FIELD -> {
+                        ensureExpectedToken(Token.START_OBJECT, xcp.currentToken(), xcp)
+                        while (xcp.nextToken() != Token.END_OBJECT) {
+                            val filter = xcp.currentName()
+                            xcp.nextToken()
+
+                            when (filter) {
+                                POLICY_ID_FIELD -> policyID = xcp.text()
+                                STATE_FIELD -> state = xcp.text()
+                                ACTION_FIELD -> actionType = xcp.text()
+                                FAILED_FIELD -> failed = xcp.booleanValue()
+                            }
+                        }
+                    }
+                }
+            }
+
+            return ExplainFilter(policyID, state, actionType, failed)
+        }
+    }
+}
+
+fun BoolQueryBuilder.filterByPolicyID(explainFilter: ExplainFilter?): BoolQueryBuilder {
+    if (explainFilter?.policyID != null) {
+        this.filter(QueryBuilders.termsQuery(MANAGED_INDEX_POLICY_ID_FIELD, explainFilter.policyID))
+    }
+
+    return this
+}
diff --git a/...tlin/org/opensearch/indexmanagement/indexstatemanagement/resthandler/RestExplainAction.kt b/...tlin/org/opensearch/indexmanagement/indexstatemanagement/resthandler/RestExplainAction.kt
@@ -9,8 +9,11 @@ import org.apache.logging.log4j.LogManager
 import org.opensearch.client.node.NodeClient
 import org.opensearch.core.common.Strings
 import org.opensearch.common.logging.DeprecationLogger
+import org.opensearch.core.xcontent.XContentParser.Token
+import org.opensearch.core.xcontent.XContentParserUtils.ensureExpectedToken
 import org.opensearch.indexmanagement.IndexManagementPlugin.Companion.ISM_BASE_URI
 import org.opensearch.indexmanagement.IndexManagementPlugin.Companion.LEGACY_ISM_BASE_URI
+import org.opensearch.indexmanagement.indexstatemanagement.model.ExplainFilter
 import org.opensearch.indexmanagement.indexstatemanagement.transport.action.explain.ExplainAction
 import org.opensearch.indexmanagement.indexstatemanagement.transport.action.explain.ExplainRequest
 import org.opensearch.indexmanagement.indexstatemanagement.util.DEFAULT_EXPLAIN_VALIDATE_ACTION
@@ -28,6 +31,7 @@ import org.opensearch.rest.RestHandler.ReplacedRoute
 import org.opensearch.rest.RestHandler.Route
 import org.opensearch.rest.RestRequest
 import org.opensearch.rest.RestRequest.Method.GET
+import org.opensearch.rest.RestRequest.Method.POST
 import org.opensearch.rest.action.RestToXContentListener
 
 private val log = LogManager.getLogger(RestExplainAction::class.java)
@@ -52,6 +56,14 @@ class RestExplainAction : BaseRestHandler() {
             ReplacedRoute(
                 GET, "$EXPLAIN_BASE_URI/{index}",
                 GET, "$LEGACY_EXPLAIN_BASE_URI/{index}"
+            ),
+            ReplacedRoute(
+                POST, EXPLAIN_BASE_URI,
+                POST, LEGACY_EXPLAIN_BASE_URI
+            ),
+            ReplacedRoute(
+                POST, "$EXPLAIN_BASE_URI/{index}",
+                POST, "$LEGACY_EXPLAIN_BASE_URI/{index}"
             )
         )
     }
@@ -69,6 +81,14 @@ class RestExplainAction : BaseRestHandler() {
 
         val indexType = request.param(TYPE_PARAM_KEY, DEFAULT_INDEX_TYPE)
 
+        val explainFilter = if (request.method() == RestRequest.Method.POST) {
+            val xcp = request.contentParser()
+            ensureExpectedToken(Token.START_OBJECT, xcp.nextToken(), xcp)
+            ExplainFilter.parse(xcp)
+        } else {
+            null
+        }
+
         val clusterManagerTimeout = parseClusterManagerTimeout(
             request, DeprecationLogger.getLogger(RestExplainAction::class.java), name
         )
@@ -78,6 +98,7 @@ class RestExplainAction : BaseRestHandler() {
             request.paramAsBoolean("local", false),
             clusterManagerTimeout,
             searchParams,
+            explainFilter,
             request.paramAsBoolean(SHOW_POLICY_QUERY_PARAM, DEFAULT_EXPLAIN_SHOW_POLICY),
             request.paramAsBoolean(SHOW_VALIDATE_ACTION, DEFAULT_EXPLAIN_VALIDATE_ACTION),
             indexType

diff --git a/...pensearch/indexmanagement/indexstatemanagement/transport/action/explain/ExplainRequest.kt b/...pensearch/indexmanagement/indexstatemanagement/transport/action/explain/ExplainRequest.kt
@@ -12,6 +12,7 @@ import org.opensearch.core.common.io.stream.StreamInput
 import org.opensearch.core.common.io.stream.StreamOutput
 import org.opensearch.common.unit.TimeValue
 import org.opensearch.indexmanagement.common.model.rest.SearchParams
+import org.opensearch.indexmanagement.indexstatemanagement.model.ExplainFilter
 import org.opensearch.indexmanagement.indexstatemanagement.util.DEFAULT_INDEX_TYPE
 import java.io.IOException
 
@@ -21,6 +22,7 @@ class ExplainRequest : ActionRequest {
     val local: Boolean
     val clusterManagerTimeout: TimeValue
     val searchParams: SearchParams
+    val explainFilter: ExplainFilter?
     val showPolicy: Boolean
     val validateAction: Boolean
     val indexType: String
@@ -31,6 +33,7 @@ class ExplainRequest : ActionRequest {
         local: Boolean,
         clusterManagerTimeout: TimeValue,
         searchParams: SearchParams,
+        explainFilter: ExplainFilter?,
         showPolicy: Boolean,
         validateAction: Boolean,
         indexType: String
@@ -39,6 +42,7 @@ class ExplainRequest : ActionRequest {
         this.local = local
         this.clusterManagerTimeout = clusterManagerTimeout
         this.searchParams = searchParams
+        this.explainFilter = explainFilter
         this.showPolicy = showPolicy
         this.validateAction = validateAction
         this.indexType = indexType
@@ -50,6 +54,7 @@ class ExplainRequest : ActionRequest {
         local = sin.readBoolean(),
         clusterManagerTimeout = sin.readTimeValue(),
         searchParams = SearchParams(sin),
+        explainFilter = sin.readOptionalWriteable(::ExplainFilter),
         showPolicy = sin.readBoolean(),
         validateAction = sin.readBoolean(),
         indexType = sin.readString()
@@ -72,6 +77,7 @@ class ExplainRequest : ActionRequest {
         out.writeBoolean(local)
         out.writeTimeValue(clusterManagerTimeout)
         searchParams.writeTo(out)
+        out.writeOptionalWriteable(explainFilter)
         out.writeBoolean(showPolicy)
         out.writeBoolean(validateAction)
         out.writeString(indexType)

diff --git a/...h/indexmanagement/indexstatemanagement/transport/action/explain/TransportExplainAction.kt b/...h/indexmanagement/indexstatemanagement/transport/action/explain/TransportExplainAction.kt
@@ -44,6 +44,7 @@ import org.opensearch.indexmanagement.indexstatemanagement.model.ManagedIndexCon
 import org.opensearch.indexmanagement.indexstatemanagement.model.Policy
 import org.opensearch.indexmanagement.common.model.rest.SearchParams
 import org.opensearch.indexmanagement.indexstatemanagement.ManagedIndexRunner.actionValidation
+import org.opensearch.indexmanagement.indexstatemanagement.model.filterByPolicyID
 import org.opensearch.indexmanagement.indexstatemanagement.opensearchapi.getManagedIndexMetadata
 import org.opensearch.indexmanagement.indexstatemanagement.transport.action.managedIndex.ManagedIndexAction
 import org.opensearch.indexmanagement.indexstatemanagement.transport.action.managedIndex.ManagedIndexRequest
@@ -162,9 +163,10 @@ class TransportExplainAction @Inject constructor(
                 .must(
                     QueryBuilders
                         .queryStringQuery(params.queryString)
-                        .defaultField(MANAGED_INDEX_NAME_KEYWORD_FIELD)
+                        .field(MANAGED_INDEX_NAME_KEYWORD_FIELD)
                         .defaultOperator(Operator.AND)
                 ).filter(QueryBuilders.termsQuery(MANAGED_INDEX_INDEX_UUID_FIELD, indexUUIDs))
+                .filterByPolicyID(request.explainFilter)
 
             val searchSourceBuilder = SearchSourceBuilder()
                 .from(params.from)
@@ -294,8 +296,32 @@ class TransportExplainAction @Inject constructor(
                 mgetMetadataReq,
                 object : ActionListener<MultiGetResponse> {
                     override fun onResponse(response: MultiGetResponse) {
-                        val metadataMap: Map<ManagedIndexMetadataDocUUID, ManagedIndexMetadataMap?> =
+                        var metadataMap: Map<ManagedIndexMetadataDocUUID, ManagedIndexMetadataMap?> =
                             response.responses.associate { it.id to getMetadata(it.response)?.toMap() }
+
+                        if (request.explainFilter != null) {
+                            metadataMap = metadataMap.filter { (_, value) ->
+                                var isValid = true
+
+                                if (value != null) {
+                                    val metaData = ManagedIndexMetaData.fromMap(value)
+
+                                    if (!request.explainFilter.byMetaData(metaData)) {
+                                        indexNames.remove(metaData.index)
+                                        indexNamesToUUIDs.remove(metaData.index)
+
+                                        if (managedIndices.contains(metaData.index)) {
+                                            totalManagedIndices--
+                                        }
+
+                                        isValid = false
+                                    }
+                                }
+
+                                isValid
+                            }
+                        }
+
                         buildResponse(indexNamesToUUIDs, metadataMap, clusterStateIndexMetadatas, threadContext)
                     }
 

diff --git a/src/main/kotlin/org/opensearch/indexmanagement/indexstatemanagement/util/RestHandlerUtils.kt b/src/main/kotlin/org/opensearch/indexmanagement/indexstatemanagement/util/RestHandlerUtils.kt
@@ -47,6 +47,7 @@ const val MANAGED_INDEX_FIELD = "managed_index"
 const val MANAGED_INDEX_NAME_KEYWORD_FIELD = "$MANAGED_INDEX_FIELD.name.keyword"
 const val MANAGED_INDEX_INDEX_FIELD = "$MANAGED_INDEX_FIELD.index"
 const val MANAGED_INDEX_INDEX_UUID_FIELD = "$MANAGED_INDEX_FIELD.index_uuid"
+const val MANAGED_INDEX_POLICY_ID_FIELD = "$MANAGED_INDEX_FIELD.policy_id"
 
 const val DEFAULT_JOB_SORT_FIELD = MANAGED_INDEX_INDEX_FIELD
 const val DEFAULT_POLICY_SORT_FIELD = "policy.policy_id.keyword"

diff --git a/...n/org/opensearch/indexmanagement/indexstatemanagement/IndexStateManagementRestTestCase.kt b/...n/org/opensearch/indexmanagement/indexstatemanagement/IndexStateManagementRestTestCase.kt
@@ -38,12 +38,7 @@ import org.opensearch.indexmanagement.IndexManagementPlugin.Companion.INDEX_STAT
 import org.opensearch.indexmanagement.IndexManagementPlugin.Companion.ISM_BASE_URI
 import org.opensearch.indexmanagement.IndexManagementPlugin.Companion.POLICY_BASE_URI
 import org.opensearch.indexmanagement.IndexManagementRestTestCase
-import org.opensearch.indexmanagement.indexstatemanagement.model.ChangePolicy
-import org.opensearch.indexmanagement.indexstatemanagement.model.ISMTemplate
-import org.opensearch.indexmanagement.indexstatemanagement.model.ManagedIndexConfig
-import org.opensearch.indexmanagement.indexstatemanagement.model.Policy
 import org.opensearch.indexmanagement.indexstatemanagement.model.Policy.Companion.POLICY_TYPE
-import org.opensearch.indexmanagement.indexstatemanagement.model.StateFilter
 import org.opensearch.indexmanagement.indexstatemanagement.resthandler.RestExplainAction
 import org.opensearch.indexmanagement.indexstatemanagement.settings.ManagedIndexSettings
 import org.opensearch.indexmanagement.indexstatemanagement.util.FAILED_INDICES
@@ -71,6 +66,12 @@ import org.opensearch.jobscheduler.spi.schedule.IntervalSchedule
 import org.opensearch.rest.RestRequest
 import org.opensearch.search.SearchModule
 import org.opensearch.core.rest.RestStatus
+import org.opensearch.indexmanagement.indexstatemanagement.model.ChangePolicy
+import org.opensearch.indexmanagement.indexstatemanagement.model.ExplainFilter
+import org.opensearch.indexmanagement.indexstatemanagement.model.ISMTemplate
+import org.opensearch.indexmanagement.indexstatemanagement.model.ManagedIndexConfig
+import org.opensearch.indexmanagement.indexstatemanagement.model.Policy
+import org.opensearch.indexmanagement.indexstatemanagement.model.StateFilter
 import org.opensearch.indexmanagement.rollup.randomTermQuery
 import org.opensearch.test.OpenSearchTestCase
 import java.io.IOException
@@ -473,6 +474,8 @@ abstract class IndexStateManagementRestTestCase : IndexManagementRestTestCase()
 
     protected fun ManagedIndexConfig.toHttpEntity(): HttpEntity = StringEntity(toJsonString(), APPLICATION_JSON)
 
+    protected fun ExplainFilter.toHttpEntity(): HttpEntity = StringEntity(toJsonString(), APPLICATION_JSON)
+
     protected fun ChangePolicy.toHttpEntity(): HttpEntity {
         var string = "{\"${ChangePolicy.POLICY_ID_FIELD}\":\"$policyID\","
         if (state != null) {

diff --git a/src/test/kotlin/org/opensearch/indexmanagement/indexstatemanagement/TestHelpers.kt b/src/test/kotlin/org/opensearch/indexmanagement/indexstatemanagement/TestHelpers.kt
@@ -31,6 +31,7 @@ import org.opensearch.indexmanagement.indexstatemanagement.action.SnapshotAction
 import org.opensearch.indexmanagement.indexstatemanagement.model.ChangePolicy
 import org.opensearch.indexmanagement.indexstatemanagement.model.Conditions
 import org.opensearch.indexmanagement.indexstatemanagement.model.ErrorNotification
+import org.opensearch.indexmanagement.indexstatemanagement.model.ExplainFilter
 import org.opensearch.indexmanagement.indexstatemanagement.model.ISMTemplate
 import org.opensearch.indexmanagement.indexstatemanagement.model.ManagedIndexConfig
 import org.opensearch.indexmanagement.indexstatemanagement.model.Policy
@@ -305,6 +306,15 @@ fun randomByteSizeValue(): ByteSizeValue =
  * End - Conditions helper functions
  */
 
+fun randomExplainFilter(
+    policyID: String? = if (OpenSearchRestTestCase.randomBoolean()) OpenSearchRestTestCase.randomAlphaOfLength(10) else null,
+    state: String? = if (OpenSearchRestTestCase.randomBoolean()) OpenSearchRestTestCase.randomAlphaOfLength(10) else null,
+    actionType: String? = if (OpenSearchRestTestCase.randomBoolean()) OpenSearchRestTestCase.randomAlphaOfLength(10) else null,
+    failed: Boolean? = if (OpenSearchRestTestCase.randomBoolean()) OpenSearchRestTestCase.randomBoolean() else null
+): ExplainFilter {
+    return ExplainFilter(policyID, state, actionType, failed)
+}
+
 fun randomChangePolicy(
     policyID: String = OpenSearchRestTestCase.randomAlphaOfLength(10),
     state: String? = if (OpenSearchRestTestCase.randomBoolean()) OpenSearchRestTestCase.randomAlphaOfLength(10) else null,
@@ -470,6 +480,11 @@ fun AllocationAction.toJsonString(): String {
     return this.toXContent(builder, ToXContent.EMPTY_PARAMS).string()
 }
 
+fun ExplainFilter.toJsonString(): String {
+    val builder = XContentFactory.jsonBuilder()
+    return this.toXContent(builder, ToXContent.EMPTY_PARAMS).string()
+}
+
 fun ChangePolicy.toJsonString(): String {
     val builder = XContentFactory.jsonBuilder()
     return this.toXContent(builder, ToXContent.EMPTY_PARAMS).string()