建立单进程组件运行时

internal/controller/components.go

@@ -0,0 +1,75 @@
+// Package controller composes independently runnable scheduler and backend workers.
+package controller
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"slices"
+	"strings"
+
+	"golang.org/x/sync/errgroup"
+)
+
+type ComponentName string
+
+const (
+	Scheduler ComponentName = "scheduler"
+	PodWorker ComponentName = "pod-worker"
+	VMWorker  ComponentName = "vm-worker"
+)
+
+var defaultComponents = []ComponentName{Scheduler, PodWorker, VMWorker}
+
+// Selection parses --components. An empty value enables all components.
+type Selection []ComponentName
+
+func ParseSelection(value string) (Selection, error) {
+	if strings.TrimSpace(value) == "" || strings.TrimSpace(value) == "all" {
+		return append(Selection(nil), defaultComponents...), nil
+	}
+	var selected Selection
+	for _, raw := range strings.Split(value, ",") {
+		name := ComponentName(strings.TrimSpace(raw))
+		if !slices.Contains(defaultComponents, name) {
+			return nil, fmt.Errorf("unknown controller component %q", name)
+		}
+		if !slices.Contains(selected, name) {
+			selected = append(selected, name)
+		}
+	}
+	if len(selected) == 0 {
+		return nil, errors.New("at least one controller component is required")
+	}
+	return selected, nil
+}
+
+type Component interface {
+	Run(context.Context) error
+}
+
+type Registry map[ComponentName]Component
+
+// Run starts exactly the selected components in one process. The first real
+// failure cancels its peers; ordinary context cancellation is graceful.
+func Run(ctx context.Context, selection Selection, registry Registry) error {
+	group, groupContext := errgroup.WithContext(ctx)
+	for _, name := range selection {
+		component, ok := registry[name]
+		if !ok || component == nil {
+			return fmt.Errorf("component %q is not configured", name)
+		}
+		name, component := name, component
+		group.Go(func() error {
+			err := component.Run(groupContext)
+			if errors.Is(err, context.Canceled) && groupContext.Err() != nil {
+				return nil
+			}
+			if err != nil {
+				return fmt.Errorf("component %s: %w", name, err)
+			}
+			return nil
+		})
+	}
+	return group.Wait()
+}