1. 确认IAM角色是否正确命名，且当前账户有权限访问此角色。可使用以下代码进行确认：

import boto3

iam_client = boto3.client('iam')

response = iam_client.list_roles()

while 'IsTruncated' in response and response['IsTruncated']: response = iam_client.list_roles(Marker=response['Marker'])

for role in response['Roles']: print(role['RoleName'])

2. 确认IAM角色是否已经附加到EC2实例上。可使用以下代码进行确认：

import boto3

iam_client = boto3.client('iam') ec2_client = boto3.client('ec2')

instance_id = 'i-1a2b3c4d5e6f'

response = ec2_client.describe_iam_instance_profile_associations(Filters=[{'Name': 'instance-id', 'Values': [instance_id]}])

if len(response['IamInstanceProfileAssociations']) > 0: for assoc in response['IamInstanceProfileAssociations']: response = iam_client.get_role(RoleName=assoc['IamInstanceProfile']['Arn'].split('/')[-1]) print(response['Role']) else: print('No IAM role attached to instance')

3. 如果发现问题，可在AWS控制台上重新创建IAM角色，并将其附加到EC2实例上。