将变量传递到Step Function start_execution()输入参数中

时间:2019-03-27 14:40:43

标签: json python-3.x amazon-web-services boto3 aws-step-functions

我正在将boto3Python 3.6配合使用来开始执行步进功能。步进功能旨在在我的所有帐户之间共享我的基本AMI。我有4个变量需要传递给input参数以开始执行。这些是AMI ID,我拥有的帐户的帐户列表,源帐户和KMS密钥。 AMI ID和帐户列表是在我的代码中构造的,并且是需要动态传递的变量。根据文档,inputstring that contains the JSON input data for the execution,并给出以下示例:"input": "{\"ami_id\" : \"ami_id\"}"。我的问题是如何将有问题的变量作为值传递给此参数?我的代码在下面,带有追溯:

CODE:

import boto3
import json

#   Get an STS token to assume roles into AWS accounts
def get_sts_token(**kwargs):
    role_arn = kwargs['RoleArn']
    region_name = kwargs['RegionName']
    sts = boto3.client(
        'sts',
    region_name=region_name,
    )
    token = sts.assume_role(
        RoleArn=role_arn,
        RoleSessionName='GetInstances',
        DurationSeconds=900,
    )
    return token["Credentials"]

def get_accounts():
    role_arn = "arn:aws:iam::xxxxxxxxxx:role/list-accounts-role"
    region_name = "us-east-1"

    token = get_sts_token(RoleArn=role_arn, RegionName=region_name)

    access_key = token['AccessKeyId']
    secret_key = token['SecretAccessKey']       
    session_token = token['SessionToken']

    client = boto3.client('organizations', 
    aws_access_key_id=access_key,
    aws_secret_access_key=secret_key,
    aws_session_token=session_token)

    moreAccounts=True
    nexttoken=''
    global accountList
    accountList =[]

    while moreAccounts:
        if (len(nexttoken)>0):
            accounts=client.list_accounts(NextToken=nexttoken)
        else:
            accounts=client.list_accounts()
        if 'NextToken' in accounts:
            nexttoken=accounts['NextToken']
        else:
            moreAccounts=False
        for account in accounts['Accounts']:
            if account['Status'] != 'SUSPENDED' and account['Status'] != 'CLOSED' :
                account_id = account['Id']
                accountList.append(account_id)


    print(accountList)

def trigger_sfn():
    ssm = boto3.client('ssm')
    role_arn = "arn:aws:iam::xxxxxxxx:role/execute-sfn"
    region_name = "us-east-1"

    ami_id = ssm.get_parameter(Name='/BaseAMI/newest')['Parameter']['Value']
    print(ami_id)

    token = get_sts_token(RoleArn=role_arn, RegionName=region_name)
    print(token)

    access_key = token['AccessKeyId']
    secret_key = token['SecretAccessKey']       
    session_token = token['SessionToken']

    sfn = boto3.client('stepfunctions', 
    aws_access_key_id=access_key,
    aws_secret_access_key=secret_key,
    aws_session_token=session_token)

    response = sfn.start_execution(
    stateMachineArn='arn:aws:states:us-east-1:xxxxxxxx:stateMachine:ami-share',
    input="{\"ami_id\": ami_id, \"source_account_id\": \"112233445566\", \"accountList\": accountList, \"kms_key_arn\": \"alias/aws/ebs\"}"
)

    print(response)

TRACE:

An error occurred (InvalidExecutionInput) when calling the 
StartExecution operation: Invalid State Machine Execution Input: 
'com.fasterxml.jackson.core.JsonParseException: Unrecognized token 
'ami_id': was expecting ('true', 'false' or 'null')
at [Source: (String)"{"ami_id": ami_id, "source_account_id": 
"112233445566", "accountList": accountList, "kms_key_arn": 
"alias/aws/ebs"}"; line: 1, column: 18]': InvalidExecutionInput
Traceback (most recent call last):
File "/var/task/lambda_function.py", line 6, in lambda_handler
trigger_sfn()
File "/var/task/lambda_function.py", line 96, in trigger_sfn
input="{\"ami_id\": ami_id, \"source_account_id\": \"112233445566\", 
\"accountList\": accountList, \"kms_key_arn\": \"alias/aws/ebs\"}"
File "/var/runtime/botocore/client.py", line 314, in _api_call
return self._make_api_call(operation_name, kwargs)
File "/var/runtime/botocore/client.py", line 612, in _make_api_call
raise error_class(parsed_response, operation_name)
botocore.errorfactory.InvalidExecutionInput: An error occurred 
(InvalidExecutionInput) when calling the StartExecution operation: 
Invalid State Machine Execution Input: 
'com.fasterxml.jackson.core.JsonParseException: Unrecognized token 
'ami_id': was expecting ('true', 'false' or 'null')
at [Source: (String)"{"ami_id": ami_id, "source_account_id": 
"112233445566", "accountList": accountList, "kms_key_arn": 
"alias/aws/ebs"}"; line: 1, column: 18]'

1 个答案:

答案 0 :(得分:1)

您可以像这样将变量的值添加到字符串中:

input="{\"ami_id\": \"" + ami_id + "\", \"source_account_id\": \"112233445566\", \"accountList\": accountList, \"kms_key_arn\": \"alias/aws/ebs\"}"

您的代码当前发送文字字符串“ ami_id”,而不是ami_id的变量值