Python Boto3 - 数据未正确写入DynamoDB

Posted 2021-04-07

我有一个XML文件，我正在使用Python解析字符串并写入AWS中的DynamoDB表。标签是<IMAGE_ID>和<CVSS_FINAL>。当我遍历和print()这些值时，它返回所有这些值。但是，当我写入Dynamo时，只写入一行数据。所以，我不明白为什么print()返回所有内容，但只有一行写入数据存储区。

码：

import boto3
import lxml
from lxml import etree

def WriteItemToTable():
    s3 = boto3.resource('s3')
    bucket = ‘xxxxxxxxxxxx’
    key = 'vuln_data.xml'
    dynamo = boto3.client('dynamodb')

    obj = s3.Object(‘xxxxxxxxxx’, 'vuln_data.xml')
    body = obj.get()['Body'].read()

    image_id = etree.fromstring(body).findall('HOST_LIST/HOST/EC2_INFO/IMAGE_ID')
    risk_score = etree.fromstring(body).findall('HOST_LIST/HOST/VULN_INFO_LIST/VULN_INFO/CVSS_FINAL')

    for el in image_id:
        i = el.text
        print(i)

    for el in risk_score:
        j = el.text
        print(j)

    response = dynamo.put_item(
    TableName='ExistingAMI',
        Item={
            'AMI_ID': {
                'S': i
             },
            'CVSS_SCORE': {
                'S': j
            },
         }
       )

WriteItemToTable()

XML：

<HOST_LIST>
    <HOST>
      <EC2_INFO>
        <PUBLIC_DNS_NAME><![CDATA[ec2-xxxxxxxxxxx.compute-1.amazonaws.com]]></PUBLIC_DNS_NAME>
        <IMAGE_ID><![CDATA[ami-xxxxxx]]></IMAGE_ID>
      </EC2_INFO>
      <OPERATING_SYSTEM><![CDATA[Linux x.y]]></OPERATING_SYSTEM>
      <VULN_INFO_LIST>
        <VULN_INFO>
          <QID id="qid_x”>x</QID>
          <TYPE>Vuln</TYPE>
          <CVSS_FINAL>3.5</CVSS_FINAL>
          <RESULT><![CDATA[TLSv1.0 is supported]]></RESULT>
        </VULN_INFO>
        <VULN_INFO>
      <QID id="qid_xxxx">xxxxx</QID>
      <CVSS_FINAL>2.1</CVSS_FINAL>
    </VULN_INFO>
    <VULN_INFO>
      <QID id="qid_xxxx">xxxx</QID>
      <CVSS_FINAL>4.3</CVSS_FINAL>
      <RESULT><![CDATA[TLSv1.0 is supported]]></RESULT>
    </VULN_INFO>
    </VULN_INFO_LIST>
    </HOST>
    <HOST>
      <EC2_INFO>
        <PUBLIC_DNS_NAME><![CDATA[ec2-xxxxxxxxx.compute-1.amazonaws.com]]></PUBLIC_DNS_NAME>
        <IMAGE_ID><![CDATA[ami-yyyyyy]]></IMAGE_ID>
      </EC2_INFO>
      <OPERATING_SYSTEM><![CDATA[Amazon Linux]]></OPERATING_SYSTEM>
      <VULN_INFO_LIST>
        <VULN_INFO>
          <QID id=“x”>x</QID>
          <CVSS_FINAL>3.6</CVSS_FINAL>
        </VULN_INFO>
    </VULN_INFO_LIST>
    </HOST>
</HOST_LIST>

print（）输出：

ami-xxxxxx
ami-yyyyyy
3.5
3.6

发电机表：

Dynamo Table

答案

虽然我对DynamoDB一无所知，但是你的Python代码只应传递一个i和j值，因为你的dynamo.put_item代码块没有嵌套在任何一个for循环中，因此它们会获取它们最后指定的值。

只需在一个循环中运行image_id和risk_score搜索，这个循环可以嵌套在<HOST>级别。并考虑xpath()，lxml。而且当您导入其方法import lxml时，不需要etree调用。

doc = etree.fromstring(body)  # PARSE ONLY ONCE

hosts = doc.xpath('//HOST')

for h in hosts:
    i = h.xpath('EC2_INFO/IMAGE_ID')[0].text
    print(i)

    j = h.xpath('VULN_INFO_LIST/VULN_INFO/CVSS_FINAL')[0].text
    print(j)

    response = dynamo.put_item(
        TableName='ExistingAMI',
        Item={
            'AMI_ID': {
                 'S': i
             },
            'CVSS_SCORE': {
                'S': j
            },
         }
    )

WriteItemToTable()

# ami-xxxxxx
# 3.5
# ami-yyyyyy
# 3.6

---

对于多个CVSS_FINAL，使用XPath解析为<CSVSS_FINAL>然后使用ancestor::*检索相应的IMAGE_ID

cvss = obj.xpath('//CVSS_FINAL')   # ALL CVSS_FINAL NODES

for c in cvss:        
    i = c.xpath('ancestor::HOST/EC2_INFO/IMAGE_ID')[0].text
    print(i)

    j = c.text
    print(j)

    k = c.xpath('concat(following-sibling::RESULT, "")')
    print(k)

    response = dynamo.put_item( ... )

# ami-xxxxxx
# 3.5
# TLSv1.0 is supported
# ami-xxxxxx
# 2.1
# 
# ami-xxxxxx
# 4.3
# TLSv1.0 is supported
# ami-yyyyyy
# 3.6
#