From f450d71a256934e95897ba5f472a739e0e9ec885 Mon Sep 17 00:00:00 2001
From: Raj Kamal Singh <1133322+rkssisodiya@users.noreply.github.com>
Date: Thu, 7 Sep 2023 17:47:09 +0530
Subject: [PATCH] fix: avoid pipeline builder panic when first op is disabled
 (#3500)

* fix: avoid pipeline builder panic if first op is disabled

* chore: use pipeline builder test to trigger getOperator panic

---------

Co-authored-by: Nityananda Gohain <nityanandagohain@gmail.com>
---
 .../app/logparsingpipeline/pipelineBuilder.go |  2 +-
 .../pipelineBuilder_test.go                   | 23 +++++++++++++++++++
 .../integration/logparsingpipeline_test.go    |  4 ++--
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/pkg/query-service/app/logparsingpipeline/pipelineBuilder.go b/pkg/query-service/app/logparsingpipeline/pipelineBuilder.go
index 93b60c37cc..568cbe20ce 100644
--- a/pkg/query-service/app/logparsingpipeline/pipelineBuilder.go
+++ b/pkg/query-service/app/logparsingpipeline/pipelineBuilder.go
@@ -58,7 +58,7 @@ func getOperators(ops []model.PipelineOperator) []model.PipelineOperator {
 	filteredOp := []model.PipelineOperator{}
 	for i, operator := range ops {
 		if operator.Enabled {
-			if i > 0 {
+			if len(filteredOp) > 0 {
 				filteredOp[len(filteredOp)-1].Output = operator.ID
 			}
 			filteredOp = append(filteredOp, operator)
diff --git a/pkg/query-service/app/logparsingpipeline/pipelineBuilder_test.go b/pkg/query-service/app/logparsingpipeline/pipelineBuilder_test.go
index 4973467d1b..a8017ac439 100644
--- a/pkg/query-service/app/logparsingpipeline/pipelineBuilder_test.go
+++ b/pkg/query-service/app/logparsingpipeline/pipelineBuilder_test.go
@@ -163,6 +163,29 @@ var prepareProcessorTestData = []struct {
 			},
 		},
 	},
+	{
+		Name: "first op disabled",
+		Operators: []model.PipelineOperator{
+			{
+				ID:      "move_filename",
+				Output:  "move_function",
+				Enabled: false,
+				Name:    "move_filename",
+			},
+			{
+				ID:      "move_function",
+				Enabled: true,
+				Name:    "move_function",
+			},
+		},
+		Output: []model.PipelineOperator{
+			{
+				ID:      "move_function",
+				Enabled: true,
+				Name:    "move_function",
+			},
+		},
+	},
 }
 
 func TestPreparePipelineProcessor(t *testing.T) {
diff --git a/pkg/query-service/tests/integration/logparsingpipeline_test.go b/pkg/query-service/tests/integration/logparsingpipeline_test.go
index d2f1b60910..a268714294 100644
--- a/pkg/query-service/tests/integration/logparsingpipeline_test.go
+++ b/pkg/query-service/tests/integration/logparsingpipeline_test.go
@@ -231,8 +231,8 @@ func (tb *LogPipelinesTestBed) PostPipelinesToQSExpectingStatusCode(
 
 	if response.StatusCode != expectedStatusCode {
 		tb.t.Fatalf(
-			"Received response status %d after posting log pipelines. Expected: %d",
-			response.StatusCode, expectedStatusCode,
+			"Received response status %d after posting log pipelines. Expected: %d\nResponse body:%s\n",
+			response.StatusCode, expectedStatusCode, string(responseBody),
 		)
 	}