建立单进程组件运行时

docs/runner-protocol-roadmap.md

@@ -18,6 +18,10 @@ dynamic-runner scheduler
                 └──────────────────────► Gitea
 ```
 
+controller 使用单一 Go 二进制；默认在同一进程启用 `scheduler`、`pod-worker` 和
+`vm-worker`，也可通过 `--components` 只启用其中一部分。组件是独立应用服务边界，
+共享进程不意味着共享后端状态或把 assignment 降级为内存 channel。
+
 这与“收到 webhook 后临时注册另一个 act_runner”不同。`FetchTask` 已经完成任务分配，
 不能再期待 Gitea 把同一个 task 分配给随后启动的 runner。协议调度器必须让 executor
 执行已经领取的 task，并继续完成日志、状态、心跳、取消和最终结果上报。

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()
+}

internal/controller/components_test.go

@@ -0,0 +1,63 @@
+package controller
+
+import (
+	"context"
+	"errors"
+	"sync"
+	"testing"
+)
+
+func TestParseSelectionDefaultsToAll(t *testing.T) {
+	for _, input := range []string{"", "all"} {
+		selection, err := ParseSelection(input)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(selection) != 3 || selection[0] != Scheduler || selection[1] != PodWorker || selection[2] != VMWorker {
+			t.Fatalf("selection = %v", selection)
+		}
+	}
+}
+
+func TestParseSelectionAllowsOneOrMoreComponents(t *testing.T) {
+	selection, err := ParseSelection("vm-worker,scheduler,vm-worker")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(selection) != 2 || selection[0] != VMWorker || selection[1] != Scheduler {
+		t.Fatalf("selection = %v", selection)
+	}
+	if _, err := ParseSelection("webhook"); err == nil {
+		t.Fatal("expected obsolete component to be rejected")
+	}
+}
+
+type componentFunc func(context.Context) error
+
+func (f componentFunc) Run(ctx context.Context) error { return f(ctx) }
+
+func TestRunStartsSelectedComponentsAndCancelsPeers(t *testing.T) {
+	started := make(chan ComponentName, 2)
+	peerStopped := make(chan struct{})
+	var once sync.Once
+	registry := Registry{
+		Scheduler: componentFunc(func(context.Context) error {
+			started <- Scheduler
+			return errors.New("poll failed")
+		}),
+		PodWorker: componentFunc(func(ctx context.Context) error {
+			started <- PodWorker
+			<-ctx.Done()
+			once.Do(func() { close(peerStopped) })
+			return ctx.Err()
+		}),
+	}
+	err := Run(context.Background(), Selection{Scheduler, PodWorker}, registry)
+	if err == nil || !errors.Is(err, context.Canceled) && err.Error() != "component scheduler: poll failed" {
+		t.Fatalf("Run() error = %v", err)
+	}
+	<-peerStopped
+	if len(started) != 2 {
+		t.Fatalf("started components = %d", len(started))
+	}
+}