ELB creation with multiple subnets in the same AZ cause "Default VPC not found" error

[harpermann]

Hi Hashicorp,
Terraform is great stuff. We're using it a ton. We found a minor bug were we get a misleading error message.

Terraform Version

** terraform -v = Terraform v0.9.8 **

Terraform Configuration Files

**ELB with multiple subnets in same AZ in subnet ids**
resource "aws_elb" "jenkins" {
  name               = "elb-jenkins-${var.dp_env}"
  #availability_zones = [  "us-west-2a", "use-west-2b", "us-west-2c" ]
  subnets            = [ "subnet-xxxxxxx", "subnet-xxxxxxxx", "subnet-xxxxxxxx", "subnet-xxxxxxxx", "subnet-xxxxxxx" ]
  security_groups    = [
    "${var.sg_app_elb}",
    "${var.sg_app_elb_ppd_apigw}",
    "${var.sg_app_elb_prd_apigw}",
    "${var.sg_app_elb_perf_portal}"
  ]

Debug Output

• use subnets or availability_zones but not both on ELB Create. (with subnets defined and multiple subnets in the same AZ, and availability_zones commented out)
• InvalidConfigurationRequest: Default VPC not found (with subnets commented and using only avaiability_zones)
• Failure adding ELB subnets: InvalidConfigurationRequest: ELB cannot be attached to multiple subnets in the same AZ" (after creating ELB with subnets with one subnet per AZ, no availability_zones, then updating with multiple subnets in same AZ)

Crash Output

not crashing

Expected Behavior

**On ELB create with multiple subnets in the same AZ, should get error:
Failure adding ELB subnets: InvalidConfigurationRequest: ELB cannot be attached to multiple subnets in the same AZ
**

Actual Behavior

Got misleading "Default VPC not found" error

Steps to Reproduce

• If we use only the subnets (some in same AZ), we get an error saying either we need to use subnets or availability_zones but not both on ELB Create.
• if we coment out subnets and use 3 AZ's, we get the error on ELB Create: InvalidConfigurationRequest: Default VPC not found
• If we start with 3 subnets not in multi AZ's ELB create works.
• if we add 3 more subnets in same AZ's for a total of 6, we get " Failure adding ELB subnets: InvalidConfigurationRequest: ELB cannot be attached to multiple subnets in the same AZ"
• This is likely the error we want in the first case.

Important Factoids

Are there anything atypical about your situation that we should know? For example: is Terraform running in a wrapper script or in a CI system? Are you passing any unusual command line options or environment variables to opt-in to non-default behavior?

• We run with a wrapper script, but this is TF configuration and not caused by the script.

References

Looked but couldn't find related issues.

[hashibot]

This issue has been automatically migrated to hashicorp/terraform-provider-aws#1497 because it looks like an issue with that provider. If you believe this is not an issue with the provider, please reply to this issue and let us know.

[abhishikth01]

not able to launch elb in a new VPC. it launches in the default vpc of mine.

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.