From 1d32ef065ca80421865b645d2bcb5f3fd8b1e4c8 Mon Sep 17 00:00:00 2001
From: fearful-symmetry <alexpkristiansen@icloud.com>
Date: Thu, 12 Oct 2023 11:16:37 -0700
Subject: [PATCH] improve nil handling, add tests

---
 libbeat/idxmgmt/lifecycle/es_client_handler.go |  8 +++++---
 libbeat/idxmgmt/lifecycle/es_client_test.go    | 18 ++++++++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/libbeat/idxmgmt/lifecycle/es_client_handler.go b/libbeat/idxmgmt/lifecycle/es_client_handler.go
index c9077547a5b6..5bc6d70eac83 100644
--- a/libbeat/idxmgmt/lifecycle/es_client_handler.go
+++ b/libbeat/idxmgmt/lifecycle/es_client_handler.go
@@ -64,9 +64,11 @@ func NewESClientHandler(c ESClient, info beat.Info, cfg RawConfig) (*ESClientHan
 
 		// unpack name value separately
 		dsName := DefaultDSLName()
-		err := cfg.DSL.Unpack(&dsName)
-		if err != nil {
-			return nil, fmt.Errorf("error unpacking DSL data stream name: %w", err)
+		if cfg.DSL != nil {
+			err := cfg.DSL.Unpack(&dsName)
+			if err != nil {
+				return nil, fmt.Errorf("error unpacking DSL data stream name: %w", err)
+			}
 		}
 		lifecycleCfg.PolicyName = dsName.DataStreamPattern
 
diff --git a/libbeat/idxmgmt/lifecycle/es_client_test.go b/libbeat/idxmgmt/lifecycle/es_client_test.go
index aa6c55f274f9..400285db2d6d 100644
--- a/libbeat/idxmgmt/lifecycle/es_client_test.go
+++ b/libbeat/idxmgmt/lifecycle/es_client_test.go
@@ -81,6 +81,14 @@ func TestESSetup(t *testing.T) {
 		ILM: config.MustNewConfigFrom(mapstr.M{"enabled": true, "policy_name": "test", "check_exists": true}),
 		DSL: config.MustNewConfigFrom(mapstr.M{"enabled": true, "data_stream_pattern": "%{[beat.name]}-%{[beat.version]}", "check_exists": true}),
 	}
+	withDSLBlank := RawConfig{
+		ILM: config.MustNewConfigFrom(mapstr.M{"enabled": false, "policy_name": "test", "check_exists": true}),
+		DSL: nil,
+	}
+	withILMBlank := RawConfig{
+		ILM: nil,
+		DSL: config.MustNewConfigFrom(mapstr.M{"enabled": false, "data_stream_pattern": "%{[beat.name]}-%{[beat.version]}", "check_exists": true}),
+	}
 
 	cases := map[string]struct {
 		serverless      bool
@@ -174,6 +182,16 @@ func TestESSetup(t *testing.T) {
 			cfg:        bothDisabledConfig,
 			err:        false,
 		},
+		"serverless-with-bare-config": {
+			serverless: true,
+			cfg:        withDSLBlank,
+			err:        false,
+		},
+		"stateful-with-bare-config": {
+			serverless: false,
+			cfg:        withILMBlank,
+			err:        false,
+		},
 	}
 
 	for name, test := range cases {