chore: add a more targeted version

Author: VihasMakwana

confmap/merge.go

@@ -5,47 +5,65 @@ package confmap // import "go.opentelemetry.io/collector/confmap"
 
 import (
 	"reflect"
+
+	"github.com/gobwas/glob"
+	"github.com/knadh/koanf/maps"
 )
 
 func mergeAppend(src, dest map[string]any) error {
-	// mergeAppend recursively merges the src map into the dest map (left to right),
-	// modifying and expanding the dest map in the process.
-	// This function does not overwrite lists, and ensures that the final value is a name-aware
-	// copy of lists from src and dest.
+	// Compile the globs once
+	patterns := []string{
+		"service::extensions",
+		"service::**::receivers",
+		"service::**::exporters",
+	}
+	var globs []glob.Glob
+	for _, p := range patterns {
+		if g, err := glob.Compile(p); err == nil {
+			globs = append(globs, g)
+		}
+	}
+
+	// Flatten both source and destination maps
+	srcFlat, _ := maps.Flatten(src, []string{}, KeyDelimiter)
+	destFlat, _ := maps.Flatten(dest, []string{}, KeyDelimiter)
 
-	for sKey, sVal := range src {
-		dVal, dOk := dest[sKey]
-		if !dOk {
-			// key is not present in destination config. Hence, add it to destination map
-			dest[sKey] = sVal
+	for key, sVal := range srcFlat {
+		if !isMatch(key, globs) {
 			continue
 		}
 
+		dVal, exists := destFlat[key]
+		if !exists {
+			continue // Let maps.Merge handle missing keys
+		}
+
 		srcVal := reflect.ValueOf(sVal)
 		destVal := reflect.ValueOf(dVal)
 
-		if destVal.Kind() != srcVal.Kind() {
-			// different kinds. Override the destination map
-			dest[sKey] = sVal
-			continue
-		}
-
-		switch srcVal.Kind() {
-		case reflect.Array, reflect.Slice:
-			// both of them are array. Merge them
-			dest[sKey] = mergeSlice(srcVal, destVal)
-		case reflect.Map:
-			// both of them are maps. Recursively call the mergeAppend
-			_ = mergeAppend(sVal.(map[string]any), dVal.(map[string]any))
-		default:
-			// any other datatype. Override the destination map
-			dest[sKey] = sVal
+		// Only merge if the value is a slice or array; let maps.Merge handle other types
+		if srcVal.Kind() == reflect.Slice || srcVal.Kind() == reflect.Array {
+			srcFlat[key] = mergeSlice(srcVal, destVal)
 		}
 	}
 
+	// Unflatten and merge
+	mergedSrc := maps.Unflatten(srcFlat, KeyDelimiter)
+	maps.Merge(mergedSrc, dest)
+
 	return nil
 }
 
+// isMatch checks if a key matches any glob in the list
+func isMatch(key string, globs []glob.Glob) bool {
+	for _, g := range globs {
+		if g.Match(key) {
+			return true
+		}
+	}
+	return false
+}
+
 func mergeSlice(src, dest reflect.Value) any {
 	slice := reflect.MakeSlice(src.Type(), 0, src.Cap()+dest.Cap())
 	for i := 0; i < dest.Len(); i++ {

confmap/testdata/merge-append-scenarios.yaml

@@ -66,7 +66,7 @@
         pipelines:
             traces:
                 receivers: [nop, nop2]
-                processors: [nop, nop2]
+                processors: [nop2]
                 exporters: [nop, nop2]
 - name: merge-mode-append
   configs:
@@ -134,7 +134,7 @@
         pipelines:
             traces:
                 receivers: [nop, nop2]
-                processors: [nop, nop2]
+                processors: [nop2]
                 exporters: [nop, nop2]
 - name: merge-mode-append-override-old-values
   configs:
@@ -335,70 +335,6 @@
             traces:
                 receivers: [nop, nop2, nop3]
                 exporters: [nop, nop2, nop3]
-- name: merge-mode-append-processor
-  configs:
-    -
-        receivers:
-            nop:
-
-        exporters:
-            nop:
-
-        extensions:
-            nop:
-        processors:
-            processor:
-                path: [path]
-        service:
-            extensions: [nop]
-            pipelines:
-                traces:
-                    receivers: [nop]
-                    processors: [processor]
-                    exporters: [nop]
-    -
-        receivers:
-            nop2:
-
-        exporters:
-            nop2:
-
-        extensions:
-            nop2:
-        processors:
-            processor:
-                path: [path2]
-
-        service:
-            extensions: [nop2]
-            pipelines:
-                traces:
-                    receivers: [nop2]
-                    processors: [processor]
-                    exporters: [nop2]
-  expected: 
-    receivers:
-        nop:
-        nop2:
-
-    exporters:
-        nop:
-        nop2:
-
-    extensions:
-        nop:
-        nop2:
-    processors:
-        processor:
-            path: [path, path2]
-
-    service:
-        extensions: [nop, nop2]
-        pipelines:
-            traces:
-                receivers: [nop, nop2]
-                processors: [processor]
-                exporters: [nop, nop2]
 - name: merge-mode-append-processor-service
   configs:
     -
@@ -454,7 +390,7 @@
         nop2:
     processors:
         processor:
-            path: [path, path2]
+            path: [path2]
 
     service:
         extensions: [nop, nop2]
@@ -543,7 +479,7 @@
 
     processors:
         processor:
-            path: [path, path2, path3]
+            path: [path3]
         processor2:
 
     service:
@@ -603,19 +539,16 @@
                 receivers: [nop]
                 processors: [nop]
                 exporters: [nop]
-- name: merge-mode-extra-processor
+- name: merge-mode-multiple-pipelines
   configs:
     -
         receivers:
             nop:
                 key: val
 
         processors:
-            attributes/example:
-                actions:
-                - key: key
-                value: "value"
-                action: upsert
+            nop:
+                key: val
 
         exporters:
             nop:
@@ -631,41 +564,68 @@
                     receivers: [nop]
                     processors: [attributes/example]
                     exporters: [nop]
+                logs:
+                    receivers: [nop]
+                    processors: [attributes/example]
+                    exporters: [nop]
     -
-        extensions:
-            nop2:
+        receivers:
+            nop1:
+                key: val
+
         processors:
-            nop2:
+            nop1:
+                key: val
+
+        exporters:
+            nop1:
+                key: 2
+
+        extensions:
+            nop1:
+
         service:
-            extensions: [nop2]
+            extensions: [nop1]
             pipelines:
                 traces:
-                    processors: [nop2]
+                    receivers: [nop1]
+                    processors: [nop1]
+                    exporters: [nop1]
+                logs:
+                    receivers: [nop1]
+                    processors: [nop1]
+                    exporters: [nop1]
   expected: 
     receivers:
         nop:
             key: val
+        nop1:
+            key: val
 
     processors:
-        nop2:
-        attributes/example:
-            actions:
-            - key: key
-            value: "value"
-            action: upsert
+        nop:
+            key: val
+        nop1:
+            key: val
 
     exporters:
         nop:
             key: 2
+        nop1:
+            key: 2
 
     extensions:
         nop:
-        nop2:
+        nop1:
 
     service:
-        extensions: [nop, nop2]
+        extensions: [nop, nop1]
         pipelines:
             traces:
-                receivers: [nop]
-                processors: [attributes/example, nop2]
-                exporters: [nop]
+                receivers: [nop, nop1]
+                processors: [nop1]
+                exporters: [nop, nop1]
+            logs:
+                receivers: [nop, nop1]
+                processors: [nop1]
+                exporters: [nop, nop1]