relax relationship between corrosion service, init cluster with new store

internal/machine/store/store.go

@@ -1,14 +1,20 @@
 package store
 
 import (
+	"context"
 	_ "embed"
+	"errors"
 	"fmt"
 	"uncloud/internal/corrosion"
 	"uncloud/internal/machine/api/pb"
 )
 
-//go:embed schema.sql
-var Schema string
+var (
+	//go:embed schema.sql
+	Schema string
+
+	ErrKeyNotFound = errors.New("key not found")
+)
 
 // Store is a cluster store backed by a distributed Corrosion database.
 type Store struct {
@@ -19,6 +25,28 @@ func New(corro *corrosion.APIClient) *Store {
 	return &Store{corro: corro}
 }
 
+func (s *Store) Get(ctx context.Context, key string, value any) error {
+	rows, err := s.corro.QueryContext(ctx, "SELECT value FROM cluster WHERE key = ?", key)
+	if err != nil {
+		return err
+	}
+	if !rows.Next() {
+		if rows.Err() != nil {
+			return rows.Err()
+		}
+		return ErrKeyNotFound
+	}
+	if err = rows.Scan(value); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (s *Store) Put(ctx context.Context, key string, value any) error {
+	_, err := s.corro.ExecContext(ctx, "INSERT OR REPLACE INTO cluster (key, value) VALUES (?, ?)", key, value)
+	return err
+}
+
 func (s *Store) CreateMachine(machine *pb.MachineInfo) error {
 	return fmt.Errorf("not implemented")
 }