Fix: pipeline alias collisions shouldnt lead to duplicate log processors (#5372)

* chore: add test validating pipeline alias collisions dont lead to bad config recommendations

* chore: emit error log on detecting duplicate processors in generated config

* chore: ensure collector config processor names for pipelines are unique

* chore: minor cleanups

pkg/query-service/app/logparsingpipeline/collector_config.go

@@ -142,6 +142,11 @@ func checkDuplicateString(pipeline []string) bool {
 	for _, processor := range pipeline {
 		name := processor
 		if _, ok := exists[name]; ok {
+			zap.L().Error(
+				"duplicate processor name detected in generated collector config for log pipelines",
+				zap.String("processor", processor),
+				zap.Any("pipeline", pipeline),
+			)
 			return true
 		}
 

pkg/query-service/app/logparsingpipeline/collector_config_test.go

@@ -5,7 +5,10 @@ import (
 	"testing"
 
 	. "github.com/smartystreets/goconvey/convey"
+	"github.com/stretchr/testify/require"
 	"go.signoz.io/signoz/pkg/query-service/constants"
+	v3 "go.signoz.io/signoz/pkg/query-service/model/v3"
+	"gopkg.in/yaml.v3"
 )
 
 var buildProcessorTestData = []struct {
@@ -204,3 +207,89 @@ func TestBuildLogsPipeline(t *testing.T) {
 		})
 	}
 }
+
+func TestPipelineAliasCollisionsDontResultInDuplicateCollectorProcessors(t *testing.T) {
+	require := require.New(t)
+
+	baseConf := []byte(`
+        receivers:
+          memory:
+            id: in-memory-receiver
+        exporters:
+          memory:
+            id: in-memory-exporter
+        service:
+          pipelines:
+            logs:
+              receivers:
+                - memory
+              processors: []
+              exporters:
+                - memory
+      `)
+
+	makeTestPipeline := func(name string, alias string) Pipeline {
+		return Pipeline{
+			OrderId: 1,
+			Name:    name,
+			Alias:   alias,
+			Enabled: true,
+			Filter: &v3.FilterSet{
+				Operator: "AND",
+				Items: []v3.FilterItem{
+					{
+						Key: v3.AttributeKey{
+							Key:      "method",
+							DataType: v3.AttributeKeyDataTypeString,
+							Type:     v3.AttributeKeyTypeTag,
+						},
+						Operator: "=",
+						Value:    "GET",
+					},
+				},
+			},
+			Config: []PipelineOperator{
+				{
+					ID:        "regex",
+					Type:      "regex_parser",
+					Enabled:   true,
+					Name:      "regex parser",
+					ParseFrom: "attributes.test_regex_target",
+					ParseTo:   "attributes",
+					Regex:     `^\s*(?P<json_data>{.*})\s*$`,
+				},
+			},
+		}
+	}
+
+	testPipelines := []Pipeline{
+		makeTestPipeline("test pipeline 1", "pipeline-alias"),
+		makeTestPipeline("test pipeline 2", "pipeline-alias"),
+	}
+
+	recommendedConfYaml, apiErr := GenerateCollectorConfigWithPipelines(
+		baseConf, testPipelines,
+	)
+	require.Nil(apiErr, fmt.Sprintf("couldn't generate config recommendation: %v", apiErr))
+
+	var recommendedConf map[string]interface{}
+	err := yaml.Unmarshal(recommendedConfYaml, &recommendedConf)
+	require.Nil(err, "couldn't unmarshal recommended config")
+
+	logsProcessors := recommendedConf["service"].(map[string]any)["pipelines"].(map[string]any)["logs"].(map[string]any)["processors"].([]any)
+
+	require.Equal(
+		len(logsProcessors), len(testPipelines),
+		"test pipelines not included in recommended config as expected",
+	)
+
+	recommendedConfYaml2, apiErr := GenerateCollectorConfigWithPipelines(
+		baseConf, testPipelines,
+	)
+	require.Nil(apiErr, fmt.Sprintf("couldn't generate config recommendation again: %v", apiErr))
+	require.Equal(
+		string(recommendedConfYaml), string(recommendedConfYaml2),
+		"collector config should not change across recommendations for same set of pipelines",
+	)
+
+}

pkg/query-service/app/logparsingpipeline/pipelineBuilder.go

@@ -24,7 +24,7 @@ func CollectorConfProcessorName(p Pipeline) string {
 func PreparePipelineProcessor(pipelines []Pipeline) (map[string]interface{}, []string, error) {
 	processors := map[string]interface{}{}
 	names := []string{}
-	for _, v := range pipelines {
+	for pipelineIdx, v := range pipelines {
 		if !v.Enabled {
 			continue
 		}
@@ -70,6 +70,12 @@ func PreparePipelineProcessor(pipelines []Pipeline) (map[string]interface{}, []s
 			Operators: v.Config,
 		}
 		name := CollectorConfProcessorName(v)
+
+		// Ensure name is unique
+		if _, nameExists := processors[name]; nameExists {
+			name = fmt.Sprintf("%s-%d", name, pipelineIdx)
+		}
+
 		processors[name] = processor
 		names = append(names, name)
 	}