L0 ELB created with only one subnet configured

[davemeyer]

Expected behavior

ELB is generally configured with 3 subnets in 3 AZs

Actual behavior

Only a single subnet in a single AZ was configured

Events as seen from ECS:
The individual tasks were terminating with a SIGTERM: 7 error. That alone didn't tell me much, but the ECS event logs showed the real issue:

(instance i-038db12314955a4d7) is unhealthy in elb l0-chunnelprod0108-Product5c5b5 due to (reason Instance is in the EC2 Availability Zone for which LoadBalancer is not configured to route traffic to.)

Steps to reproduce the behavior

🤷‍♀️ first time i have seen this.

• V0.10.8