allow non alphanum strings

internal/runtime/internal/controller/node_config_foreach.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 	"sync"
 	"time"
+	"unicode"
 
 	"github.com/go-kit/log"
 	"github.com/grafana/alloy/internal/component"
@@ -383,7 +384,9 @@ func computeHash(s string) string {
 func hashObject(obj any) string {
 	//TODO: Test what happens if there is a "true" string and a true bool in the collection.
 	switch v := obj.(type) {
-	case int, string, bool:
+	case string:
+		return replaceNonAlphaNumeric(v)
+	case int, bool:
 		return fmt.Sprintf("%v", v)
 	case float64:
 		// Dots are not valid characters in Alloy syntax identifiers.
@@ -394,6 +397,18 @@ func hashObject(obj any) string {
 	}
 }
 
+func replaceNonAlphaNumeric(s string) string {
+	var builder strings.Builder
+	for _, r := range s {
+		if unicode.IsLetter(r) || unicode.IsDigit(r) {
+			builder.WriteRune(r)
+		} else {
+			builder.WriteRune('_')
+		}
+	}
+	return builder.String()
+}
+
 type NoopRegistry struct{}
 
 var _ prometheus.Registerer = NoopRegistry{}

internal/runtime/internal/controller/node_config_foreach_test.go

@@ -226,6 +226,19 @@ func TestCreateCustomComponentsCollectionObjectsWithUpdate(t *testing.T) {
 	require.ElementsMatch(t, keys, []string{"foreach_be19d02a2ccb2cbc2c47e90dcad8446a50459577449624176398d1f2aa6cd23a_1", "foreach_1464766cf9c8fd1095d0f7a22abe0632b6a6d44c3eeae65766086350eef3ac33_1"})
 }
 
+func TestNonAlphaNumericString(t *testing.T) {
+	config := `foreach "default" {
+		collection = ["123./st%4$"]
+		var = "num"
+		template {
+		}
+	}`
+	foreachConfigNode := NewForeachConfigNode(getBlockFromConfig(t, config), getComponentGlobals(t), nil)
+	require.NoError(t, foreachConfigNode.Evaluate(vm.NewScope(make(map[string]interface{}))))
+	customComponentIds := foreachConfigNode.moduleController.(*ModuleControllerMock).CustomComponents
+	require.ElementsMatch(t, customComponentIds, []string{"foreach_123__st_4__1"})
+}
+
 func getBlockFromConfig(t *testing.T, config string) *ast.BlockStmt {
 	file, err := parser.ParseFile("", []byte(config))
 	require.NoError(t, err)

internal/runtime/testdata/foreach_stringer/foreach_6.txtar

@@ -0,0 +1,22 @@
+A collection containing a string with a dot.
+
+-- main.alloy --
+foreach "testForeach" {
+  collection = ["aaa.bbb"]
+  var = "item"
+
+  template {
+    testcomponents.stringer "st" {
+      input_string = item
+      forward_to = [testcomponents.string_receiver.log.receiver]
+    }
+  }
+}
+
+// Receive strings and append them to a log,
+// separated by a new line.
+testcomponents.string_receiver "log" {
+}
+
+-- expected_debug_info.txt --
+"aaa.bbb"