Does Lambda Need A Vpc

By default lambda runs your functions in a secure vpc with access to aws services and the internet.

Does lambda need a vpc. If you run out of eni capacity this will cause your lambda functions to fail. When building an application with aws lambda you may need to host your lambda function in a vpc. If you do need to use a vpc keep in mind that each time a lambda function is executed it uses a proportion of your eni capacity from the subnet.

When you connect a function to a vpc in your account the function can t access the internet unless your vpc provides access. In most cases we do not need to run our lambda function in a vpc and it is recommended not to run in a vpc in these situations as a best practice. You can continue to apply normal network security controls and follow best practices on vpc configuration.

From the aws docs they state you must have sufficient eni capacity to support your lambda scaling requirements. Then you have no choice but to deploy that function in a vpc as well. You still control the subnet and security group configurations of these network interfaces.

Internet and service access for vpc connected functions. But if you ve got a fleet of ec2s already deployed in a vpc and your lambda function needs access them. Lambda owns this vpc which isn t connected to your account s default vpc.

Your lambda functions still need the iam permissions required to create and delete network interfaces in your vpc. The most common reason for this is because your lambda function will use other resources which aren t accessible from the public internet such as a relational database or redis instance. Lambda functions are protected by aws identity and access management iam service which provides both authentication and authorization.

Or if your org requires full network logging of all your workloads then you ll also need vpc and their flow logs to comply with such requests. You don t need vpcs to secure lambda unlike ec2 instances which need vpcs to shield them from malicious traffic.