Add stability lvl to config blocks

internal/runtime/foreach_test.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/grafana/alloy/internal/component"
+	"github.com/grafana/alloy/internal/featuregate"
 	"github.com/grafana/alloy/internal/runtime"
 	alloy_runtime "github.com/grafana/alloy/internal/runtime"
 	"github.com/prometheus/client_golang/prometheus"
@@ -103,7 +104,7 @@ func buildTestForEach(t *testing.T, filename string) testForEachFile {
 func testConfigForEach(t *testing.T, config string, reloadConfig string, update func(), expectedMetrics *string, expectedDurationMetrics *int) {
 	defer verifyNoGoroutineLeaks(t)
 	reg := prometheus.NewRegistry()
-	ctrl, f := setup(t, config, reg)
+	ctrl, f := setup(t, config, reg, featuregate.StabilityExperimental)
 
 	err := ctrl.LoadSource(f, nil, "")
 	require.NoError(t, err)

internal/runtime/import_git_test.go

@@ -14,6 +14,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/grafana/alloy/internal/featuregate"
 	"github.com/grafana/alloy/internal/vcs"
 	"github.com/stretchr/testify/require"
 )
@@ -55,7 +56,7 @@ testImport.add "cc" {
 	runGit(t, testRepo, "commit", "-m \"test\"")
 
 	defer verifyNoGoroutineLeaks(t)
-	ctrl, f := setup(t, main, nil)
+	ctrl, f := setup(t, main, nil, featuregate.StabilityPublicPreview)
 	err = ctrl.LoadSource(f, nil, "")
 	require.NoError(t, err)
 	ctx, cancel := context.WithCancel(context.Background())
@@ -122,7 +123,7 @@ testImport.add "cc" {
 	runGit(t, testRepo, "commit", "-m \"test\"")
 
 	defer verifyNoGoroutineLeaks(t)
-	ctrl, f := setup(t, main, nil)
+	ctrl, f := setup(t, main, nil, featuregate.StabilityPublicPreview)
 	err = ctrl.LoadSource(f, nil, "")
 	require.NoError(t, err)
 	ctx, cancel := context.WithCancel(context.Background())
@@ -205,7 +206,7 @@ testImport.add "cc" {
 	runGit(t, testRepo, "commit", "-m \"test2\"")
 
 	defer verifyNoGoroutineLeaks(t)
-	ctrl, f := setup(t, main, nil)
+	ctrl, f := setup(t, main, nil, featuregate.StabilityPublicPreview)
 	err = ctrl.LoadSource(f, nil, "")
 	require.NoError(t, err)
 	ctx, cancel := context.WithCancel(context.Background())
@@ -269,7 +270,7 @@ testImport.add "cc" {
 
 	defer verifyNoGoroutineLeaks(t)
 
-	ctrl, f := setup(t, main, nil)
+	ctrl, f := setup(t, main, nil, featuregate.StabilityPublicPreview)
 	err = ctrl.LoadSource(f, nil, "")
 	require.NoError(t, err)
 	ctx, cancel := context.WithCancel(context.Background())
@@ -354,7 +355,7 @@ testImport.add "cc" {
 	runGit(t, testRepo, "commit", "-m \"test\"")
 
 	defer verifyNoGoroutineLeaks(t)
-	ctrl, f := setup(t, main, nil)
+	ctrl, f := setup(t, main, nil, featuregate.StabilityPublicPreview)
 	err = ctrl.LoadSource(f, nil, "")
 	expectedErr := vcs.InvalidRevisionError{
 		Revision: "nonexistent",

internal/runtime/import_test.go

@@ -299,7 +299,7 @@ func TestImportError(t *testing.T) {
 
 func testConfig(t *testing.T, config string, reloadConfig string, update func()) {
 	defer verifyNoGoroutineLeaks(t)
-	ctrl, f := setup(t, config, nil)
+	ctrl, f := setup(t, config, nil, featuregate.StabilityPublicPreview)
 
 	err := ctrl.LoadSource(f, nil, "")
 	require.NoError(t, err)
@@ -352,7 +352,7 @@ func testConfig(t *testing.T, config string, reloadConfig string, update func())
 
 func testConfigError(t *testing.T, config string, expectedError string) {
 	defer verifyNoGoroutineLeaks(t)
-	ctrl, f := setup(t, config, nil)
+	ctrl, f := setup(t, config, nil, featuregate.StabilityPublicPreview)
 	err := ctrl.LoadSource(f, nil, "")
 	require.ErrorContains(t, err, expectedError)
 	ctx, cancel := context.WithCancel(context.Background())
@@ -369,13 +369,13 @@ func testConfigError(t *testing.T, config string, expectedError string) {
 	}()
 }
 
-func setup(t *testing.T, config string, reg prometheus.Registerer) (*alloy_runtime.Runtime, *alloy_runtime.Source) {
+func setup(t *testing.T, config string, reg prometheus.Registerer, stability featuregate.Stability) (*alloy_runtime.Runtime, *alloy_runtime.Source) {
 	s, err := logging.New(os.Stderr, logging.DefaultOptions)
 	require.NoError(t, err)
 	ctrl := alloy_runtime.New(alloy_runtime.Options{
 		Logger:       s,
 		DataPath:     t.TempDir(),
-		MinStability: featuregate.StabilityPublicPreview,
+		MinStability: stability,
 		Reg:          reg,
 		Services:     []service.Service{},
 	})

internal/runtime/internal/controller/loader_test.go

@@ -353,6 +353,19 @@ func TestLoader(t *testing.T) {
 		diags = applyFromContent(t, l, nil, nil, []byte(invalidFile))
 		require.ErrorContains(t, diags.ErrorOrNil(), `block declare.a already declared at TestLoader/Declare_block_redefined_after_reload:2:4`)
 	})
+
+	t.Run("Foreach incorrect feature stability", func(t *testing.T) {
+		invalidFile := `
+			foreach "a" {
+				collection = [5]
+				var = "item"
+				template {}
+			}
+		`
+		l := controller.NewLoader(newLoaderOptions())
+		diags := applyFromContent(t, l, nil, []byte(invalidFile), nil)
+		require.ErrorContains(t, diags.ErrorOrNil(), `config block "foreach" is at stability level "experimental", which is below the minimum allowed stability level "public-preview". Use --stability.level command-line flag to enable "experimental"`)
+	})
 }
 
 func TestLoader_Services(t *testing.T) {

internal/runtime/internal/controller/node_config.go

@@ -3,6 +3,7 @@ package controller
 import (
 	"fmt"
 
+	"github.com/grafana/alloy/internal/featuregate"
 	"github.com/grafana/alloy/internal/runtime/internal/importsource"
 	"github.com/grafana/alloy/syntax/ast"
 	"github.com/grafana/alloy/syntax/diag"
@@ -16,9 +17,26 @@ const (
 	foreachID       = "foreach"
 )
 
+// Add config blocks that are not GA. Config blocks that are not specified here are considered GA.
+var configBlocksUnstable = map[string]featuregate.Stability{
+	foreachID: featuregate.StabilityExperimental,
+}
+
 // NewConfigNode creates a new ConfigNode from an initial ast.BlockStmt.
 // The underlying config isn't applied until Evaluate is called.
 func NewConfigNode(block *ast.BlockStmt, globals ComponentGlobals, customReg *CustomComponentRegistry) (BlockNode, diag.Diagnostics) {
+	var diags diag.Diagnostics
+
+	if err := checkFeatureStability(block.GetBlockName(), globals.MinStability); err != nil {
+		diags.Add(diag.Diagnostic{
+			Severity: diag.SeverityLevelError,
+			Message:  err.Error(),
+			StartPos: ast.StartPos(block).Position(),
+			EndPos:   ast.EndPos(block).Position(),
+		})
+		return nil, diags
+	}
+
 	switch block.GetBlockName() {
 	case argumentBlockID:
 		return NewArgumentConfigNode(block, globals), nil
@@ -33,7 +51,6 @@ func NewConfigNode(block *ast.BlockStmt, globals ComponentGlobals, customReg *Cu
 	case foreachID:
 		return NewForeachConfigNode(block, globals, customReg), nil
 	default:
-		var diags diag.Diagnostics
 		diags.Add(diag.Diagnostic{
 			Severity: diag.SeverityLevelError,
 			Message:  fmt.Sprintf("invalid config block type %s while creating new config node", block.GetBlockName()),
@@ -44,6 +61,14 @@ func NewConfigNode(block *ast.BlockStmt, globals ComponentGlobals, customReg *Cu
 	}
 }
 
+func checkFeatureStability(blockName string, minStability featuregate.Stability) error {
+	blockStability, exist := configBlocksUnstable[blockName]
+	if exist {
+		return featuregate.CheckAllowed(blockStability, minStability, fmt.Sprintf("config block %q", blockName))
+	}
+	return nil
+}
+
 // ConfigNodeMap represents the config BlockNodes in their explicit types.
 // This is helpful when validating node conditions specific to config node
 // types.