当 AWS Lambda 运行在 VPC 中,访问其他 AWS 服务时,必须使用私有网络访问点 (VPC 终端点) 或 NAT 网关。但是,某些服务没有对应的 VPC 终端点类型。这个问题可以通过使用代理(例如跨区域 VPC 启用)或配置 NAT 网关来解决。
以下是使用 NAT 网关的 Python 代码示例:
import json
import urllib.parse
import boto3
print('Loading function')
s3 = boto3.client('s3')
ec2 = boto3.client('ec2')
def lambda_handler(event, context):
# Get instance ID from EC2 metadata
instance_id = urllib.request.urlopen('http://169.254.169.254/latest/meta-data/instance-id').read().decode()
# Get VPC ID and subnet ID for instance
response = ec2.describe_instances(InstanceIds=[instance_id])
vpc_id = response['Reservations'][0]['Instances'][0]['VpcId']
subnet_id = response['Reservations'][0]['Instances'][0]['SubnetId']
# Create NAT Gateway
response = ec2.create_nat_gateway(
AllocationId='ALLOC_ID',
SubnetId=subnet_id
)
# Wait for NAT Gateway to be available
nat_id = response['NatGateway']['NatGatewayId']
ec2.get_waiter('nat_gateway_available').wait(NatGatewayIds=[nat_id])
# Update route table for private subnet(s) to use NAT Gateway
response = ec2.describe_route_tables(Filters=[{'Name': 'vpc-id', 'Values': [vpc_id]}])
for table in response['RouteTables']:
for route in table['Routes']:
if 'GatewayId' in route and route['GatewayId'] == 'local':
association_id = route['RouteTableAssociationId']
ec2.replace_route(RouteTableId=table['RouteTableId'], DestinationCidrBlock=route['DestinationCidrBlock'], NatGatewayId=nat_id)
print('Updated route