事件內容的轉換類型與資料提取方法-雲Message QueueTT 版-阿里雲

事件匯流排EventBridge支援事件內容轉換，即在事件被路由到事件目標前，事件匯流排EventBridge可以把CloudEvents標準事件轉換為事件目標能接收的事件類型。本文介紹事件匯流排EventBridge提供的事件轉換類型。

背景資訊

事件匯流排EventBridge支援的事件內容轉換類型如下：

完整事件
部分事件
固定值
模板

完整事件

當轉化類型為完整事件時，事件匯流排EventBridge不對事件進行轉換，將原生CloudEvents的完整結構路由到事件目標。下表介紹經過完整事件轉換前後的事件樣本。

說明

更多CloudEvents相關資訊，請參見CloudEvents 1.0。

轉換前的事件

轉換類型

轉換後的事件

{
    "id":"7adc8c1a-645d-4476-bdef-5d6fb57f****",
    "source":"acs.oss",
    "specversion":"1.0",
    "type":"oss:ObjectCreated:PostObject",
    "datacontenttype":"application/json",
    "dataschema":"http://example.com/test.json",
    "subject":"acs:oss:cn-hangzhou:1234567:xls-papk/game_apk/123.jpg",
    "time":"2020-08-17T16:04:46.149Asia/Shanghai",
    "aliyuneventbusname":"demo-bus",
    "aliyunregionid":"Shanghai",
    "data":{
        "name":"test",
        "scope":100
    }
}

完整事件

{
    "id":"7adc8c1a-645d-4476-bdef-5d6fb57f****",
    "source":"acs.oss",
    "specversion":"1.0",
    "type":"oss:ObjectCreated:PostObject",
    "datacontenttype":"application/json",
    "dataschema":"http://example.com/test.json",
    "subject":"acs:oss:cn-hangzhou:1234567:xls-papk/game_apk/123.jpg",
    "time":"2020-08-17T16:04:46.149Asia/Shanghai",
    "aliyuneventbusname":"demo-bus",
    "aliyunregionid":"Shanghai",
    "data":{
        "name":"test",
        "scope":100
    }
}

部分事件

當轉換類型為部分事件時，事件匯流排EventBridge通過JSONPath從CloudEvents中提取事件中的參數，將指定的事件內容路由到事件目標。下表介紹經過部分事件轉換前後的事件樣本。

轉換前的事件

轉換類型

轉換後的事件

{
    "id":"7adc8c1a-645d-4476-bdef-5d6fb57f****",
    "source":"acs.oss",
    "specversion":"1.0",
    "type":"oss:ObjectCreated:PostObject",
    "datacontenttype":"application/json",
    "dataschema":"http://example.com/test.json",
    "subject":"acs:oss:cn-hangzhou:1234567:xls-papk/game_apk/123.jpg",
    "time":"2020-08-17T16:04:46.149Asia/Shanghai",
    "aliyuneventbusname":"demo-bus",
    "aliyunregionid":"Shanghai",
    "data":{
        "name":"test",
        "scope":100
    }
}

部分事件

$.data.name

說明

部分事件只支援定義一個變數。
value不超過10240個字元。

test

固定值

當轉換類型為固定值時，事件只起到觸發器的作用，不管事件內容是什麼，事件匯流排EventBridge都把固定值路由到事件目標。下表介紹經過固定值轉換前後的事件樣本。

轉換前的事件

轉換類型

轉換後的事件

{
    "id":"7adc8c1a-645d-4476-bdef-5d6fb57f****",
    "source":"acs.oss",
    "specversion":"1.0",
    "type":"oss:ObjectCreated:PostObject",
    "datacontenttype":"application/json",
    "dataschema":"http://example.com/test.json",
    "subject":"acs:oss:cn-hangzhou:1234567:xls-papk/game_apk/123.jpg",
    "time":"2020-08-17T16:04:46.149Asia/Shanghai",
    "aliyuneventbusname":"demo-bus",
    "aliyunregionid":"Shanghai",
    "data":{
        "name":"test",
        "scope":100
    }
}

固定值

test1

說明

value不超過10240個字元。

test1

模板

當轉換類型為模板時，通過自訂模板、定義模板裡需要的變數，事件匯流排EventBridge通過JSONPath從CloudEvents提取事件中的參數，把這些值存放在變數中，然後按照模板定義的格式路由到事件目標。下表介紹經過模板轉換前後的事件樣本。

轉換前的事件

轉換類型

轉換後的事件

{
    "id":"7adc8c1a-645d-4476-bdef-5d6fb57f****",
    "source":"acs.oss",
    "specversion":"1.0",
    "type":"oss:ObjectCreated:PostObject",
    "datacontenttype":"application/json",
    "dataschema":"http://example.com/test.json",
    "subject":"acs:oss:cn-hangzhou:1234567:xls-papk/game_apk/123.jpg",
    "time":"2020-08-17T16:04:46.149Asia/Shanghai",
    "aliyuneventbusname":"demo-bus",
    "aliyunregionid":"Shanghai",
    "data":{
        "name":"test",
        "scope":100
    }
}

模板

變數
```
{
    "name":"$.data.name",
    "constant":"Please deal with it timely."
}
```
說明
- JSONPath提取的值可以是變數，也可以是固定值。
- 定義變數不支援嵌套多層結構。
- value不超過10240個字元。

模板

The instance is broken，which name is ${name}, ${constant}

說明

template最大為10240字元。

The instance is broken，which name is test, Please deal with it timely.

您也可以建立String格式和JSON格式的模板，通過自訂模板將事件轉換成樣本輸出，然後路由到事件目標。以下為事件匯流排EventBridge支援的模板類型：

簡單String
簡單JSON
混合變數和固定值的JSON

表 1. 簡單String
轉換前的事件	轉換類型	轉換後的事件
`{ "id":"7adc8c1a-645d-4476-bdef-5d6fb57f****", "source":"acs.oss", "specversion":"1.0", "type":"oss:ObjectCreated:PostObject", "datacontenttype":"application/json", "dataschema":"http://example.com/test.json", "subject":"acs:oss:cn-hangzhou:1234567:xls-papk/game_apk/123.jpg", "time":"2020-08-17T16:04:46.149Asia/Shanghai", "aliyuneventbusname":"demo-bus", "aliyunregionid":"Shanghai", "data":{ "name":"test", "state":"RUNNING" } }`	模板變數 `{ "name":"$.data.name", "state":"$.data.state" }` 模板 `"name ${name} is in ${state}"`	`"name test is in RUNNING"`

轉換前的事件

轉換類型

轉換後的事件

{
    "id":"7adc8c1a-645d-4476-bdef-5d6fb57f****",
    "source":"acs.oss",
    "specversion":"1.0",
    "type":"oss:ObjectCreated:PostObject",
    "datacontenttype":"application/json",
    "dataschema":"http://example.com/test.json",
    "subject":"acs:oss:cn-hangzhou:1234567:xls-papk/game_apk/123.jpg",
    "time":"2020-08-17T16:04:46.149Asia/Shanghai",
    "aliyuneventbusname":"demo-bus",
    "aliyunregionid":"Shanghai",
    "data":{
        "name":"test",
        "state":"RUNNING"
    }
}

模板

變數

{
    "name":"$.data.name",
    "state":"$.data.state"
}

模板
```
"name ${name} is in ${state}"
```

"name test is in RUNNING"

表 2. 簡單JSON
轉換前的事件	轉換類型	轉換後的事件
`{ "id":"7adc8c1a-645d-4476-bdef-5d6fb57f****", "source":"acs.oss", "specversion":"1.0", "type":"oss:ObjectCreated:PostObject", "datacontenttype":"application/json", "dataschema":"http://example.com/test.json", "subject":"acs:oss:cn-hangzhou:1234567:xls-papk/game_apk/123.jpg", "time":"2020-08-17T16:04:46.149Asia/Shanghai", "aliyuneventbusname":"demo-bus", "aliyunregionid":"Shanghai", "data":{ "name":"test", "state":"RUNNING" } }`	模板變數 `{ "name":"$.data.name", "state":"$.data.state" }` 模板 `{ "name":"${name}", "state":"${state}" }`	`{ "name":"test", "state":"RUNNING" }`

轉換前的事件

轉換類型

轉換後的事件

{
    "id":"7adc8c1a-645d-4476-bdef-5d6fb57f****",
    "source":"acs.oss",
    "specversion":"1.0",
    "type":"oss:ObjectCreated:PostObject",
    "datacontenttype":"application/json",
    "dataschema":"http://example.com/test.json",
    "subject":"acs:oss:cn-hangzhou:1234567:xls-papk/game_apk/123.jpg",
    "time":"2020-08-17T16:04:46.149Asia/Shanghai",
    "aliyuneventbusname":"demo-bus",
    "aliyunregionid":"Shanghai",
    "data":{
        "name":"test",
        "state":"RUNNING"
    }
}

模板

變數

{
    "name":"$.data.name",
    "state":"$.data.state"
}

模板

{
    "name":"${name}",
    "state":"${state}"
}

{
    "name":"test",
    "state":"RUNNING"
}

表 3. 混合變數和固定值的JSON
轉換前的事件	轉換類型	轉換後的事件
`{ "id":"7adc8c1a-645d-4476-bdef-5d6fb57f****", "source":"acs.oss", "specversion":"1.0", "type":"oss:ObjectCreated:PostObject", "datacontenttype":"application/json", "dataschema":"http://example.com/test.json", "subject":"acs:oss:cn-hangzhou:1234567:xls-papk/game_apk/123.jpg", "time":"2020-08-17T16:04:46.149Asia/Shanghai", "aliyuneventbusname":"demo-bus", "aliyunregionid":"Shanghai", "data":{ "name":"test", "state":"RUNNING" } }`	模板變數 `{ "name":"$.data.name", "state":"$.data.state" }` 模板 `{ "name":"${name}", "state":[ 9, "${state}", true ], "Transformed":"Yes" }`	`{ "name":"test", "state":[ 9, "RUNNING", true ], "Transformed":"Yes" }`

轉換前的事件

轉換類型

轉換後的事件

{
    "id":"7adc8c1a-645d-4476-bdef-5d6fb57f****",
    "source":"acs.oss",
    "specversion":"1.0",
    "type":"oss:ObjectCreated:PostObject",
    "datacontenttype":"application/json",
    "dataschema":"http://example.com/test.json",
    "subject":"acs:oss:cn-hangzhou:1234567:xls-papk/game_apk/123.jpg",
    "time":"2020-08-17T16:04:46.149Asia/Shanghai",
    "aliyuneventbusname":"demo-bus",
    "aliyunregionid":"Shanghai",
    "data":{
        "name":"test",
        "state":"RUNNING"
    }
}

模板

變數

{
    "name":"$.data.name",
    "state":"$.data.state"
}

模板

{
    "name":"${name}",
    "state":[
        9,
        "${state}",
        true
    ],
    "Transformed":"Yes"
}

{
    "name":"test",
    "state":[
        9,
        "RUNNING",
        true
    ],
    "Transformed":"Yes"
}