我试图弄清楚如何使用boto3进行正确的错误处理。
我正在尝试创建一个IAM用户:
def create_user(username, iam_conn):
try:
user = iam_conn.create_user(UserName=username)
return user
except Exception as e:
return e
当调用create_user成功时，我得到一个整洁的对象，其中包含API调用的http状态代码和新创建用户的数据。
例子:
{'ResponseMetadata':
{'HTTPStatusCode': 200,
'RequestId': 'omitted'
},
u'User': {u'Arn': 'arn:aws:iam::omitted:user/omitted',
u'CreateDate': datetime.datetime(2015, 10, 11, 17, 13, 5, 882000, tzinfo=tzutc()),
u'Path': '/',
u'UserId': 'omitted',
u'UserName': 'omitted'
}
}
这很有效。但是当这个失败时(比如如果用户已经存在)，我只得到一个botocore.exceptions.ClientError类型的对象，其中只有文本告诉我哪里出错了。
例子:
ClientError('调用CreateUser操作时发生错误(EntityAlreadyExists):省略名称的用户已经存在。')
这(AFAIK)使得错误处理非常困难，因为我不能只是打开结果的http状态代码(409用户已经存在根据AWS API文档的IAM)。这让我觉得我一定是做错了什么。最优的方法是boto3永远不抛出异常，但juts总是返回一个反映API调用如何进行的对象。
有没有人能在这个问题上给我一些启发，或者给我指出正确的方向?
如果您正在使用Python3调用sign_up API (AWS Cognito)，您可以使用以下代码。
def registerUser(userObj):
''' Registers the user to AWS Cognito.
'''
# Mobile number is not a mandatory field.
if(len(userObj['user_mob_no']) == 0):
mobilenumber = ''
else:
mobilenumber = userObj['user_country_code']+userObj['user_mob_no']
secretKey = bytes(settings.SOCIAL_AUTH_COGNITO_SECRET, 'latin-1')
clientId = settings.SOCIAL_AUTH_COGNITO_KEY
digest = hmac.new(secretKey,
msg=(userObj['user_name'] + clientId).encode('utf-8'),
digestmod=hashlib.sha256
).digest()
signature = base64.b64encode(digest).decode()
client = boto3.client('cognito-idp', region_name='eu-west-1' )
try:
response = client.sign_up(
ClientId=clientId,
Username=userObj['user_name'],
Password=userObj['password1'],
SecretHash=signature,
UserAttributes=[
{
'Name': 'given_name',
'Value': userObj['given_name']
},
{
'Name': 'family_name',
'Value': userObj['family_name']
},
{
'Name': 'email',
'Value': userObj['user_email']
},
{
'Name': 'phone_number',
'Value': mobilenumber
}
],
ValidationData=[
{
'Name': 'email',
'Value': userObj['user_email']
},
]
,
AnalyticsMetadata={
'AnalyticsEndpointId': 'string'
},
UserContextData={
'EncodedData': 'string'
}
)
except ClientError as error:
return {"errorcode": error.response['Error']['Code'],
"errormessage" : error.response['Error']['Message'] }
except Exception as e:
return {"errorcode": "Something went wrong. Try later or contact the admin" }
return {"success": "User registered successfully. "}
错误。response['Error']['Code']将是InvalidPasswordException, UsernameExistsException等。因此，在主函数中或在调用函数的地方，可以编写逻辑以向用户提供有意义的消息。
一个响应(error.response)的例子:
{
"Error": {
"Message": "Password did not conform with policy: Password must have symbol characters",
"Code": "InvalidPasswordException"
},
"ResponseMetadata": {
"RequestId": "c8a591d5-8c51-4af9-8fad-b38b270c3ca2",
"HTTPStatusCode": 400,
"HTTPHeaders": {
"date": "Wed, 17 Jul 2019 09:38:32 GMT",
"content-type": "application/x-amz-json-1.1",
"content-length": "124",
"connection": "keep-alive",
"x-amzn-requestid": "c8a591d5-8c51-4af9-8fad-b38b270c3ca2",
"x-amzn-errortype": "InvalidPasswordException:",
"x-amzn-errormessage": "Password did not conform with policy: Password must have symbol characters"
},
"RetryAttempts": 0
}
}
如需进一步参考:
https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/cognito-idp.html#CognitoIdentityProvider.Client.sign_up
使用异常中包含的响应。这里有一个例子:
import boto3
from botocore.exceptions import ClientError
try:
iam = boto3.client('iam')
user = iam.create_user(UserName='fred')
print("Created user: %s" % user)
except ClientError as e:
if e.response['Error']['Code'] == 'EntityAlreadyExists':
print("User already exists")
else:
print("Unexpected error: %s" % e)
异常中的响应字典将包含以下内容:
(“错误”)(“代码”)。'EntityAlreadyExists'或'ValidationError'
[' responsemetdata ']['HTTPStatusCode']例:400
[“ResponseMetadata”][' RequestId ']。“d2b06652 - 88 - d7 - 11 - e5 - 99 - d0 - 812348583 - a35”
(“错误”)(“信息”)。"发生错误(EntityAlreadyExists)…"
['错误']['类型']。“发送”
有关更多信息，请参阅:
Boto3错误处理
Botocore错误处理
(更新:2018-03-07)
AWS Python SDK已经开始公开客户端上的服务异常(虽然不是资源上的异常)，你可以显式地捕获这些异常，所以现在可以像这样编写代码:
import botocore
import boto3
try:
iam = boto3.client('iam')
user = iam.create_user(UserName='fred')
print("Created user: %s" % user)
except iam.exceptions.EntityAlreadyExistsException:
print("User already exists")
except botocore.exceptions.ParamValidationError as e:
print("Parameter validation error: %s" % e)
except botocore.exceptions.ClientError as e:
print("Unexpected error: %s" % e)
不幸的是，目前没有关于这些错误/异常的文档，但你可以得到一个核心错误列表，如下所示:
import botocore
import boto3
[e for e in dir(botocore.exceptions) if e.endswith('Error')]
注意，必须同时导入botocore和boto3。如果你只导入botocore，你会发现botocore没有名为exceptions的属性。这是因为异常被boto3动态地填充到botocore中。
您可以获得以下特定于服务的异常列表(根据需要将iam替换为相关的服务):
import boto3
iam = boto3.client('iam')
[e for e in dir(iam.exceptions) if e.endswith('Exception')]
(更新:2021-09-07)
除了前面提到的客户端异常方法之外，还有一个名为aws-error-utils的第三方帮助包。
如果您正在使用Python3调用sign_up API (AWS Cognito)，您可以使用以下代码。
def registerUser(userObj):
''' Registers the user to AWS Cognito.
'''
# Mobile number is not a mandatory field.
if(len(userObj['user_mob_no']) == 0):
mobilenumber = ''
else:
mobilenumber = userObj['user_country_code']+userObj['user_mob_no']
secretKey = bytes(settings.SOCIAL_AUTH_COGNITO_SECRET, 'latin-1')
clientId = settings.SOCIAL_AUTH_COGNITO_KEY
digest = hmac.new(secretKey,
msg=(userObj['user_name'] + clientId).encode('utf-8'),
digestmod=hashlib.sha256
).digest()
signature = base64.b64encode(digest).decode()
client = boto3.client('cognito-idp', region_name='eu-west-1' )
try:
response = client.sign_up(
ClientId=clientId,
Username=userObj['user_name'],
Password=userObj['password1'],
SecretHash=signature,
UserAttributes=[
{
'Name': 'given_name',
'Value': userObj['given_name']
},
{
'Name': 'family_name',
'Value': userObj['family_name']
},
{
'Name': 'email',
'Value': userObj['user_email']
},
{
'Name': 'phone_number',
'Value': mobilenumber
}
],
ValidationData=[
{
'Name': 'email',
'Value': userObj['user_email']
},
]
,
AnalyticsMetadata={
'AnalyticsEndpointId': 'string'
},
UserContextData={
'EncodedData': 'string'
}
)
except ClientError as error:
return {"errorcode": error.response['Error']['Code'],
"errormessage" : error.response['Error']['Message'] }
except Exception as e:
return {"errorcode": "Something went wrong. Try later or contact the admin" }
return {"success": "User registered successfully. "}
错误。response['Error']['Code']将是InvalidPasswordException, UsernameExistsException等。因此，在主函数中或在调用函数的地方，可以编写逻辑以向用户提供有意义的消息。
一个响应(error.response)的例子:
{
"Error": {
"Message": "Password did not conform with policy: Password must have symbol characters",
"Code": "InvalidPasswordException"
},
"ResponseMetadata": {
"RequestId": "c8a591d5-8c51-4af9-8fad-b38b270c3ca2",
"HTTPStatusCode": 400,
"HTTPHeaders": {
"date": "Wed, 17 Jul 2019 09:38:32 GMT",
"content-type": "application/x-amz-json-1.1",
"content-length": "124",
"connection": "keep-alive",
"x-amzn-requestid": "c8a591d5-8c51-4af9-8fad-b38b270c3ca2",
"x-amzn-errortype": "InvalidPasswordException:",
"x-amzn-errormessage": "Password did not conform with policy: Password must have symbol characters"
},
"RetryAttempts": 0
}
}
如需进一步参考:
https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/cognito-idp.html#CognitoIdentityProvider.Client.sign_up
