实现持久化 assignment handoff

internal/taskassignment/assignment.go

@@ -0,0 +1,125 @@
+// Package taskassignment defines the durable handoff between the scheduler and workers.
+package taskassignment
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"slices"
+
+	"gitea.dev/actionslib/pkg/model"
+	runnerv1 "gitea.dev/actionslib/runner/v1"
+	"google.golang.org/protobuf/proto"
+
+	"git.ddupan.top/panxiao81/gitea-dynamic-runner/internal/taskidentity"
+)
+
+const wireVersion = 1
+
+type Backend string
+
+const (
+	BackendPod Backend = "pod"
+	BackendVM  Backend = "vm"
+)
+
+// Assignment is the only document persisted in the handoff queue.
+type Assignment struct {
+	ID       string
+	Backend  Backend
+	Task     *runnerv1.Task
+	Identity taskidentity.Identity
+}
+
+type envelope struct {
+	Version  int                   `json:"version"`
+	ID       string                `json:"id"`
+	Backend  Backend               `json:"backend"`
+	Task     []byte                `json:"task"`
+	Identity taskidentity.Identity `json:"identity"`
+}
+
+// New derives all trusted assignment fields from the task fetched from Gitea.
+func New(task *runnerv1.Task, trustDomain string) (Assignment, error) {
+	if task == nil || task.GetId() <= 0 {
+		return Assignment{}, errors.New("positive Gitea task ID is required")
+	}
+	identity, err := taskidentity.FromTask(task, trustDomain)
+	if err != nil {
+		return Assignment{}, err
+	}
+	backend, err := backendFromTask(task)
+	if err != nil {
+		return Assignment{}, err
+	}
+	return Assignment{
+		ID:       fmt.Sprintf("gitea-task-%d", task.GetId()),
+		Backend:  backend,
+		Task:     task,
+		Identity: identity,
+	}, nil
+}
+
+func backendFromTask(task *runnerv1.Task) (Backend, error) {
+	workflow, err := model.ReadWorkflow(bytes.NewReader(task.GetWorkflowPayload()))
+	if err != nil {
+		return "", fmt.Errorf("parse task workflow for backend: %w", err)
+	}
+	jobIDs := workflow.GetJobIDs()
+	if len(jobIDs) != 1 || workflow.GetJob(jobIDs[0]) == nil {
+		return "", fmt.Errorf("task workflow must contain exactly one non-empty job")
+	}
+	labels := workflow.GetJob(jobIDs[0]).RunsOnLabels()
+	if !slices.Contains(labels, "self-hosted") {
+		return "", fmt.Errorf("task runs-on labels must include self-hosted: %v", labels)
+	}
+	hasPod := slices.Contains(labels, string(BackendPod))
+	hasVM := slices.Contains(labels, string(BackendVM))
+	if hasPod == hasVM {
+		return "", fmt.Errorf("task runs-on labels must select exactly one of pod or vm: %v", labels)
+	}
+	if hasPod {
+		return BackendPod, nil
+	}
+	return BackendVM, nil
+}
+
+// Marshal encodes a versioned assignment. Protobuf preserves the exact Gitea task.
+func Marshal(assignment Assignment) ([]byte, error) {
+	if assignment.Task == nil {
+		return nil, errors.New("assignment task is required")
+	}
+	task, err := proto.Marshal(assignment.Task)
+	if err != nil {
+		return nil, fmt.Errorf("marshal Gitea task: %w", err)
+	}
+	return json.Marshal(envelope{
+		Version: wireVersion,
+		ID:      assignment.ID, Backend: assignment.Backend,
+		Task: task, Identity: assignment.Identity,
+	})
+}
+
+// Unmarshal re-derives trusted fields instead of trusting duplicated queue metadata.
+func Unmarshal(data []byte, trustDomain string) (Assignment, error) {
+	var wire envelope
+	if err := json.Unmarshal(data, &wire); err != nil {
+		return Assignment{}, fmt.Errorf("decode assignment: %w", err)
+	}
+	if wire.Version != wireVersion {
+		return Assignment{}, fmt.Errorf("unsupported assignment version %d", wire.Version)
+	}
+	task := new(runnerv1.Task)
+	if err := proto.Unmarshal(wire.Task, task); err != nil {
+		return Assignment{}, fmt.Errorf("unmarshal Gitea task: %w", err)
+	}
+	canonical, err := New(task, trustDomain)
+	if err != nil {
+		return Assignment{}, err
+	}
+	if wire.ID != canonical.ID || wire.Backend != canonical.Backend || wire.Identity != canonical.Identity {
+		return Assignment{}, errors.New("assignment metadata does not match its Gitea task")
+	}
+	return canonical, nil
+}