# 示例2：创建存储库自动备份
#### 场景描述
本章节指导用户通过策略接口，设置备份策略，绑定策略到存储库实现自动备份。
#### 涉及接口
- [创建策略](https://support.huaweicloud.com/api-cbr/CreatePolicy.html)：创建执行备份的周期。
- [设置存储库策略](https://support.huaweicloud.com/api-cbr/AssociateVaultPolicy.html)：关联待设置的策略到存储库。
 
#### 操作步骤
1. 创建策略。
   - 接口相关信息 URI格式：POST /v3/{project_id}/policies
     详情请参见[创建策略](https://support.huaweicloud.com/api-cbr/CreatePolicy.html)。
     
   
   - 请求示例 POST: https://*{endpoint*}/v3/0605767b5780d5762fc5c0118072a564/policies
     {endpoint}信息请从[地区和终端节点](https://developer.huaweicloud.com/endpoint?CBR)获取。
     Body:
     ```
     {
         "policy": {
             "name": "dh_test_policy",
             "operation_type" : "backup",
             "trigger": {
                 "properties": {
                     "pattern": ["FREQ=WEEKLY;BYDAY=SU,MO,TU,WE,TH,FR,SA;BYHOUR=23;BYMINUTE=00"]
     }
             },
             "operation_definition": {
                 "retention_duration_days": 30
     }
         }
     }
     ```
     
   
   - 响应示例
     ```
     {
         "policy": {
             "id": "30d7cf2d-14fc-415b-b7da-858b37f47250",
             "name": "dh_test_policy",
             "operation_type": "backup",
             "operation_definition": {
                 "retention_duration_days": 30
             },
             "enabled": true,
             "trigger": {
                 "id": "7954175b-ef2c-432c-b936-f6c83df7a593",
                 "name": "default",
                 "type": "time",
                 "properties": {
                     "pattern": [
                         "FREQ=WEEKLY;BYDAY=SU,MO,TU,WE,TH,FR,SA;BYHOUR=23;BYMINUTE=00"
                     ],
                     "start_time": "2020-08-17 08:39:44"
                 }
             },
             "associated_vaults": null
         }
     }
     ```
     
    
2. 设置存储库策略。
   - 接口相关信息 URI格式：POST /v3/{project_id}/vaults/{vault_id}/associatepolicy
     详情请参见[设置存储库策略](https://support.huaweicloud.com/api-cbr/AssociateVaultPolicy.html)。
     
   
   - 请求示例 POST: https://{endpoint}/v3/0605767b5780d5762fc5c0118072a564/vaults/ea7b8717-2543-478a-a92d-3ca7ee448f67/associatepolicy
     {endpoint}信息请从[地区和终端节点](https://developer.huaweicloud.com/endpoint?CBR)获取。
     Body:
     ```
     {
         "policy_id": "30d7cf2d-14fc-415b-b7da-858b37f47250"
     }
     ```
     
   
   - 响应示例
     ```
     {
         "associate_policy": {
             "vault_id": "ea7b8717-2543-478a-a92d-3ca7ee448f67",
             "policy_id": "30d7cf2d-14fc-415b-b7da-858b37f47250"
         }
     }
     ```