如何從 AWS Kinesis Data Stream 事件訪問數據？

Question

我正在研究使用AWS Kinesis Data Stream的 Python lambda。 但是我很難理解運動記錄事件的形狀。 例如：

{
    "Records": [
        {
            "kinesis": {
                "kinesisSchemaVersion": "1.0",
                "partitionKey": "1",
                "sequenceNumber": "49590338271490256608559692538361571095921575989136588898",
                "data": "SGVsbG8sIHRoaXMgaXMgYSB0ZXN0Lg==",
                "approximateArrivalTimestamp": 1545084650.987
            },
            "eventSource": "aws:kinesis",
            "eventVersion": "1.0",
            "eventID": "shardId-000000000006:49590338271490256608559692538361571095921575989136588898",
            "eventName": "aws:kinesis:record",
            "invokeIdentityArn": "arn:aws:iam::123456789012:role/lambda-role",
            "awsRegion": "us-east-2",
            "eventSourceARN": "arn:aws:kinesis:us-east-2:123456789012:stream/lambda-stream"
        },
        {
            "kinesis": {
                "kinesisSchemaVersion": "1.0",
                "partitionKey": "1",
                "sequenceNumber": "49590338271490256608559692540925702759324208523137515618",
                "data": "VGhpcyBpcyBvbmx5IGEgdGVzdC4=",
                "approximateArrivalTimestamp": 1545084711.166
            },
            "eventSource": "aws:kinesis",
            "eventVersion": "1.0",
            "eventID": "shardId-000000000006:49590338271490256608559692540925702759324208523137515618",
            "eventName": "aws:kinesis:record",
            "invokeIdentityArn": "arn:aws:iam::123456789012:role/lambda-role",
            "awsRegion": "us-east-2",
            "eventSourceARN": "arn:aws:kinesis:us-east-2:123456789012:stream/lambda-stream"
        }
    ]
}

來源： 將 AWS Lambda 與 Amazon Kinesis 結合使用

我最初放在這個對象中表示的運動流上的數據在哪里？ 我如何訪問這些數據？

Answer 1

您放入流中的數據表示為每個記錄的kinesis.data鍵上的 Base64 編碼字符串。 例如（截斷）：

{
    "Records": [
        {
            "kinesis": {
                ...
                "data": "SGVsbG8sIHRoaXMgaXMgYSB0ZXN0Lg==",
                ...
            },
            ...
        },
        {
            "kinesis": {
                ...
                "data": "VGhpcyBpcyBvbmx5IGEgdGVzdC4=",
                ...
            },
            ...
        }
    ]
}

要訪問數據，請遍歷每個Records對象並 Base64 解碼kinesis.data值。

import base64


for record in event["Records"]:
    decoded_data = base64.b64decode(record["kinesis"]["data"]).decode("utf-8")

    print(decoded_data)
    # Record 1: Hello, this is a test.
    # Record 2: This is only a test.

注意：此示例假設發送到 kinesis 流的數據最初是utf-8編碼，然后 kinesis b64 對其進行編碼。