AWS cli List unused elb

Question

I am pretty much new to AWS. I was trying to list the load balances which are not attached to any of the instances. I was trying describe-load-balancers using aws cli but was not able to get an option that filters the elbs.

Please provide some suggestions on how to achieve this.

Answer 1

Assuming you have aws cli setup with suitable keys, this long line of shell should list the ELBs with a count of instances attached to them. If it says zero then there are no instances attached

for i in `aws elb describe-load-balancers|sed -ne 's/"LoadBalancerName": "\(.*\)",/\1/gp'`; do echo -n "$i "; aws elb describe-load-balancers --load-balancer-name $i|grep -c InstanceId;done

Alternatively, here's a boto3 python program

import boto3
client=boto3.client('elb')
bals=client.describe_load_balancers()
for elb in bals['LoadBalancerDescriptions']:
  count=len(elb['Instances'])
  print "%s %d" % ( elb['LoadBalancerName'], count)