feat: 接入管理 Secret 凭据与连接刷新

internal/database/application/instance_service.go

@@ -0,0 +1,171 @@
+/*
+Copyright 2026.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package application
+
+import (
+	"context"
+	"errors"
+	"sync"
+
+	"git.ddupan.top/panxiao81/ayatori/internal/database/domain/instance"
+)
+
+var (
+	ErrConnection         = errors.New("management connection unavailable")
+	ErrAuthentication     = errors.New("management authentication failed")
+	ErrObservation        = errors.New("management observation failed")
+	ErrCredentialsChanged = errors.New("management credentials changed during observation")
+	ErrClosed             = errors.New("instance service closed")
+)
+
+// Database 与 Connector 复用原项目 internal/instance/service.go 的能力边界。
+// 版本查询只是本切片的连通性观察，不能产生领域 Ready。
+type Database interface {
+	Version(context.Context) (string, error)
+	Close()
+}
+
+type Connector interface {
+	Connect(context.Context, instance.Endpoint, Credentials) (Database, error)
+}
+
+type entry struct {
+	target      instance.ObservationTarget
+	credentials Credentials
+	database    Database
+}
+
+// InstanceService 由原 Service 迁移：连接复用与释放属于应用装配，不属于 SQL adapter。
+// 保留原实现串行操作的约束，防止 Close 与查询并发；controller 停止 worker 后调用 Close。
+// 不缓存能力观察，不把连接存活等同于 Ready。凭据每轮重新读取，而非只在引用变化时读取。
+type InstanceService struct {
+	mu        sync.Mutex
+	source    CredentialReader
+	connector Connector
+	entries   map[string]*entry
+	closed    bool
+}
+
+func NewInstanceService(source CredentialReader, connector Connector) (*InstanceService, error) {
+	if source == nil || connector == nil {
+		return nil, errors.New("credential source and connector required")
+	}
+	return &InstanceService{
+		source:    source,
+		connector: connector,
+		entries:   make(map[string]*entry),
+	}, nil
+}
+
+func (s *InstanceService) String() string   { return "[redacted instance service]" }
+func (s *InstanceService) GoString() string { return s.String() }
+
+// ObserveVersion 返回当前目标和凭据下的版本；任何失败均返回空结果。
+// 调用者仍需使用 CR resourceVersion 保存前提防止 spec 并发修改；本方法不建立跨系统事务。
+func (s *InstanceService) ObserveVersion(ctx context.Context, target instance.ObservationTarget) (string, error) {
+	if err := target.Validate(); err != nil {
+		return "", err
+	}
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.closed {
+		return "", ErrClosed
+	}
+	if err := ctx.Err(); err != nil {
+		return "", err
+	}
+
+	// 先读取有效凭据。读取失败时不得继续使用缓存中的旧连接。
+	name := target.Identity().Name()
+	credentials, err := s.source.Read(ctx, target.Definition().AdminCredential())
+	if err != nil {
+		s.release(name)
+		return "", credentialError(err)
+	}
+	if credentials.username == "" || credentials.password == "" {
+		s.release(name)
+		return "", ErrCredentialsInvalid
+	}
+
+	// 连接身份与有效值均未变化时复用 pgxpool；generation 本身不要求换池。
+	current := s.entries[name]
+	if current != nil && (current.target.Identity() != target.Identity() ||
+		current.target.Definition() != target.Definition() || current.credentials != credentials) {
+		s.release(name)
+		current = nil
+	}
+	if current == nil {
+		database, err := s.connector.Connect(ctx, target.Definition().Endpoint(), credentials)
+		if err != nil {
+			return "", err
+		}
+		current = &entry{
+			target:      target,
+			credentials: credentials,
+			database:    database,
+		}
+		s.entries[name] = current
+	}
+
+	version, err := current.database.Version(ctx)
+	if err != nil {
+		s.release(name)
+		return "", err
+	}
+
+	// 回读后再检查凭据，避免把轮换前取得的结果交给新凭据的调用链。
+	latest, err := s.source.Read(ctx, target.Definition().AdminCredential())
+	if err != nil {
+		s.release(name)
+		return "", credentialError(err)
+	}
+	if latest != credentials {
+		s.release(name)
+		return "", ErrCredentialsChanged
+	}
+	return version, nil
+}
+
+func credentialError(err error) error {
+	if errors.Is(err, ErrCredentialsInvalid) {
+		return ErrCredentialsInvalid
+	}
+	return ErrCredentialsUnavailable
+}
+
+// Forget 只释放本地连接；不删除数据库或 registry，不替代 Instance finalizer。
+func (s *InstanceService) Forget(name string) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.release(name)
+}
+
+func (s *InstanceService) release(name string) {
+	if current := s.entries[name]; current != nil {
+		current.database.Close()
+	}
+	delete(s.entries, name)
+}
+
+func (s *InstanceService) Close() {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.closed = true
+	for name := range s.entries {
+		s.release(name)
+	}
+}