Registering Targets
Learn to register targets with the load balancer.
We'll cover the following...
The next step is to register targets with the target group. This assigns targets (WordPress instances in our case) to the target group so the load balancer can later address them all together.
The elbv2 register-targets
command needs the following parameters:
--target-group-arn
to specify the target group.--targets
to specify the targets (our WordPress instances). To specify instances, we can use theId=<instance id>
syntax. Other options instead ofId
areip
for an IP address,lambda
for an AWS Lambda function (we will not cover those), andalb
for another load balancer (an Application Load Balancer to be precise).
We can list multiple targets separated by a space, so it looks like this:
aws elbv2 register-targets \--target-group-arn <target-group-arn> \--targets Id=<wordpress-instance-id1> Id=<wordpress-instance-id2>
To get the <target-group-arn>
directly from our target group via its name, we can use elbv2 describe-target-groups
with the --names
parameter and filter the output. This is very similar to the other describe
commands we have used already.
It looks like this:
aws elbv2 describe-target-groups \--names wordpress-instances \--query 'TargetGroups[*].TargetGroupArn' \--output text
We can then insert this into the elbv2 register-targets
command to pass the --target-group-arn
parameter to get the following: