Is there a way to have multiple external IP addresses with Elastic Beanstalk?

问题

I'm using Amazon Elastic Beanstalk with a VPC and I want to have multiple environments (workers) with different IP addresses. I don't need them to be static, I would actually prefer them to change regularly if possible.

Is there a way to have multiple environments with dynamic external IP addresses?

回答1:

It's hard to understand the use case of wanting to change the instance IP address of an Elastic Beanstalk environment. The fundamental advantage that a managed service like Elastic Beanstalk provides is abstraction over the underlying architecture for a deployment. You are given a CNAME to access the environment's (your application's) API and you shouldn't be relying on the internal IP addresses or Load Balancer URLs for anything as they can be added, removed by the beanstalk service at will.

That being said, there is a way that you can achieve having changing IPs for the underlying instances.

Elastic Beanstalk Rebuild Environment destroys the existing resources including EC2s and creates new resources resulting in your instances having new IP addresses. This would work given that a scheduled downtime (of a few minutes depending on your resources) is not a problem for this use case.

You can use one the following two ways to schedule an environment rebuild

Solution 1:

You can schedule your Rebuild Environment using a simple lambda function.

import boto3
envid=['e-awsenvidid']
client = boto3.client('elasticbeanstalk')
def handler(event, context):
    try:
         for appid in range(len(envid)):
             response = client.rebuild_environment(EnvironmentId=str(envid[appid].strip()))
             if response:
                 print('Restore environment %s' %str(envid[appid]))
             else:
                 print('Failed to Restore environment %s' %str(envid[appid]))

    except Exception as e:
        print('EnvironmentID is not valid')

In order to do this you will have to create an IAM role with the required permissions.

You can find a comprehensive guide in this AWS Guide.

Solution 2:

You can use a cron job to rebuild the environment using aws-cli. You can follow the steps below to achieve this.

Create EC2 instance
Create IAM Role with permission to rebuild environment

The following example policy would work

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": [
        "elasticbeanstalk:RebuildEnvironment"
      ],
      "Effect": "Allow",
      "Resource": "*"
    }
  ]
}

Attach the IAM role to the EC2 instance
Add a cron job using command crontab -e

The following example cron job rebuilds the environment at 12.00 am on the 1st of every month

0 0 1 * * aws elasticbeanstalk rebuild-environment --environment-name my-environment-name

Save the cronjob and exit.

It is not recommended to rebuild the environment unnecessarily, but as of now there is no explicit way to achieve your particular requirement. So hope this helps!