adding an ELB to an existing Auto Scaling group

Question

I just created two new ELBs, and I'm trying to figure out how to add one of them to an existing autoscaling group; so far the only way that this seems to be possible is by recreating the already existing autoscaling group, adding the new ELB to the one already present at creation time.

I've checked google several times trying to find out if there's another way to do this; with no luck. Is there any other way to do this or is this the only way to add an ELB to an existing autoscaling group?

I believe this isn't possible, the console and CLI tools don't allow you to modify the ELBs connected to a ASG — Rick Burgess, Jun 05 '14 at 11:12

score 2 · Answer 1 · answered Jun 12 '15 at 15:21

Now this is possible in EC2, you can attach and detach Elastic Load Balancers from Auto Scaling Groups. This is very helpful for Blue/Green deployments.

Attach/Detach an ELB to an ASG allows to change the cluster an ELB is distributing traffic, without make changes in DNS or using additional proxies.

See the official blog post of this new feature: https://aws.amazon.com/es/blogs/aws/attach-and-detach-elastic-load-balancers-from-auto-scaling-groups/

score 0 · Answer 2 · answered Mar 11 '15 at 18:20

0

To quote The Fine Manual : http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-as-group.html#cfn-as-group-loadbalancernames

LoadBalancerNames

A list of load balancers associated with this Auto Scaling group.

...

Update requires: Replacement

Important - When you update LoadBalancerNames, the entire Auto Scaling group is replaced.

answered Mar 11 '15 at 18:20

Jim Freeman

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"Update requires replacement" is only if you update the ASG using CloudFormation. – Greg Sansom Sep 22 '15 at 03:29

score 0 · Answer 3 · answered Nov 04 '15 at 03:25

This can be done in the EC2 Console by editing the Auto Scaling Group and changing the value of "Load Balancers".

It can also be done programatically, for example using PowerShell:

Add-ASLoadBalancer -AutoScalingGroupName "MyASG" -LoadBalancerName "MyELB"

score -2 · Answer 4 · answered Jan 28 '15 at 16:33

-2

You are correct, Elastic Load Balancers can only be assigned to the Autoscaling Group at the time the ASG is created. There is no way via the GUI or the CLI to add an ELB to an existing ASG.

answered Jan 28 '15 at 16:33

user2962402

57
1
5

Wrong - you can change the ELB on the ASG using both GUI and CLI. – Greg Sansom Sep 22 '15 at 03:31

adding an ELB to an existing Auto Scaling group

4 Answers4