Auto Scaling, Elastic IP - amazon-web-services

Question

When I use Network Load Balancer with Auto Scaling, everytime an instance is spawned it gets a new public IP.
I would like to have an EIP for each instance. I was hoping that when I assigned an EIP to availability zones in the Network Loadbalancer configuration would do the trick.
Is there a a way to have autoscale and static IPs for the instances spawned?
https://aws.amazon.com/blogs/aws/new-network-load-balancer-effortless-scaling-to-millions-of-requests-per-second/
According to this it looks it's not possible:
Unfortunately, there is no way to make autoscaling automatically
assign an Elastic IP address to newly launched instances
Static IP for Auto Scale in AWS
and according to this:
Assigning static IPs to auto scaled EC2 instance

Answer 1

Write a script and put it on your startup script in launch configuration for your autoscale group, that script can do anything you want, range from assigning the new EIP to check other services for the white/blacklist.
For more info read
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/user-data.html

Answer 2

As others have mentioned this can be accomplished by provisioning new EIP and using UserData to associate the instance with newly issued EIP. However, following setup would have the following issues:
1) EIP have limits by default its 5 per VPC, and even you can increase the limit you need to know the maximum number of EIP your VPC will use
2) When instance gets terminated you will need to create a process to delete staled EIP or figure out how to reassociated previously allocated EIP
Having said that I do use a static EIP in my ASG but its only for HA rather than scalability, so in the following example I'm reusing existing EIP each time I launch a new instance
#!/bin/bash -xe
INSTANCE_ID=$(curl -s http://169.254.169.254/latest/meta-data/instance-id)
aws ec2 disassociate-address --association-id ${OpenPVNEIP.AllocationId} --region ${AWS::Region} || true
aws ec2 associate-address --instance-id "${!INSTANCE_ID}" --allocation-id ${OpenPVNEIP.AllocationId} --region ${AWS::Region}

Answer 3

I created a Lambda inside a private subnet.
I linked the private subnet to a NAT Gateway and thus I managed to get a static IP for my Lambda. The limit of 5 EIPs was an issue for me.
https://aws.amazon.com/premiumsupport/knowledge-center/internet-access-lambda-function/

Answer 4

With EC2 & Auto scaling, You need using user data in EC2 to Auto Attach Elastic IP to EC2 Instance For Auto scaling
#!/bin/bash
aws configure set aws_access_key_id "XYZ..."
aws configure set aws_secret_access_key "ABC..."
aws configure set region "ap-..."
aws ec2 associate-address --instance-id "$(curl -X GET "http://169.254.169.254/latest/meta-data/instance-id")" --public-ip your_elastic_IP
Note: you should create new user & IAM have only permission associate-address to create/get aws key
Hope it be help you :)