问题
my lambda function can send message to SNS with publish method with "no VPC", but it will timeout when I put it in a VPC which has access to public internet with route and internet gateway.
Edited
I have my lambda in a public subnet which has 0.0.0.0/0 already routed to the internet gateway, so can not route it again to NAT. Is that possible to assign a EIP to lambda function
回答1:
You have to add a NAT Gateway to your VPC in order for Lambda functions (and other things in your VPC that don't have a public IP) to access anything outside the VPC. You should read the Things to Know section of this AWS announcement.
来源：https://stackoverflow.com/questions/38188532/why-aws-lambda-within-vpc-can-not-send-message-to-sns