ec2-claim-address

ec2-claim-address

Given a list of Elastic IP addresses, try to associate one with the current EC2 instance.

Getting started

Precompiled binaries

• Linux (64-bit)

Compile from source

$ go get -u github.com/grosskur/ec2-claim-address

Usage

$ ec2-claim-address ADDRESS1 [ADDRESS2 ...]

Example

$ ec2-claim-address 54.85.21.92 54.84.36.41
ec2-claim-address: getting instance-id from metadata
ec2-claim-address: found instance-id: i-9e2790df
ec2-claim-address: connecting to ec2 API endpoint
ec2-claim-address: getting address information
ec2-claim-address: claiming unassociated address: 54.84.36.41
ec2-claim-address: successfully associated: 54.84.36.41

Background

An Elastic IP is a static IP that can be remapped from one instance to another. However, an Elastic IP can only be assigned after an instance is created. Suppose you have an Auto Scaling Group and want to assign an Elastic IP to each instance. You can run ec2-claim-address with a list of possible Elastic IPs from the User Data script to automatically pick an unassociated one.