ILM history indices are removed during policy removal

es.go

@@ -710,6 +710,18 @@ func (c *Client) GetIndices(index string) ([]Index, error) {
 	return indices, nil
 }
 
+// Get a subset of indices including hidden ones
+func (c *Client) GetHiddenIndices(index string) ([]Index, error) {
+	var indices []Index
+	err := handleErrWithStruct(c.buildGetRequest(fmt.Sprintf("_cat/indices/%s?h=health,status,index,pri,rep,store.size,docs.count&expand_wildcards=open,closed,hidden", index)), &indices)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return indices, nil
+}
+
 // Get all the aliases in the cluster.
 //
 // Use case: You want to see some basic info on all the aliases of the cluster
@@ -1683,5 +1695,17 @@ func (c *Client) RemoveIndexILMPolicy(index string) error {
 		return err
 	}
 
+	ilmHistoryIndices, err := c.GetHiddenIndices(fmt.Sprintf("%s*.ds-ilm-history-*", index))
+	if err != nil {
+		return err
+	}
+
+	for _, ilmHistoryIndex := range ilmHistoryIndices {
+		err = c.DeleteIndex(ilmHistoryIndex.Name)
+		if err != nil {
+			return err
+		}
+	}
+
 	return nil
 }

es_test.go

@@ -2214,12 +2214,17 @@ func TestAllocateStalePrimaryShard(t *testing.T) {
 }
 
 func TestRemoveIndexILMPolicy(t *testing.T) {
-	testSetup := &ServerSetup{
+	ilmRemoveTestSetup := &ServerSetup{
 		Method: "POST",
 		Path:   "/test-index/_ilm/remove",
 	}
+	getIndicesTestSetup := &ServerSetup{
+		Method:   "GET",
+		Path:     "/_cat/indices/test-index*.ds-ilm-history-*",
+		Response: "[]",
+	}
 
-	host, port, ts := setupTestServers(t, []*ServerSetup{testSetup})
+	host, port, ts := setupTestServers(t, []*ServerSetup{ilmRemoveTestSetup, getIndicesTestSetup})
 	defer ts.Close()
 	client := NewClient(host, port)