feat: support Fargate in private+public EKS environments

[zimbatm]

PR o'clock

Description

The EKS cluster can be provisioned with both private and public subnets.
But Fargate only accepts private ones.

This new variable allows to override the subnets to explicitly pass the
private subnets to Fargate and work around that issue.

Checklist

• CI tests are passing
• README.md has been updated after any changes to variables and outputs. See https://github.com/terraform-aws-modules/terraform-aws-eks/#doc-generation

[aittam]

Shouldn't be better to pass the fargate subnets directly to the fargate_profiles instead of creating a new variable?

something like this:

    fargate_profiles = {
      example = {
        namespace = "default"
        subnets = ["subnet-0ca3e3d1234a56c78"]
      }
    }

The patch for the module would be similar to yours:
subnets = each.value.subnets != null ? each.value.subnets : var.subnets

[zimbatm]

@aittam like that?

[aittam]

@aittam like that?

nope, I just sent you a PR on your forked repo on how I intended it. I have tested it and it works. Look at the examples/fargate/main.tf file on how to use it.

[zimbatm]

merged

[zimbatm]

fixed the formatting issue

[zimbatm]

rebased and re-formatted with Terraform 0.14

[zimbatm]

Terraform 0.14 has been released and the formatter is not stable. So I pinned the version to 0.12.29 instead.

[RenGeng]

Any update on this PR ?

[zimbatm]

rebased again. That PR was ready but rotted a bit.

[TBeijen]

(Not a repo owner). Looks concise and complete to me.

[TBeijen]

Just tested this, specifying only the private subnets of the cluster in the fargate_profile. Works as intended.

Looking at the lookup part I'm pretty confident the default behaviour is properly preserved as well.

Edit: Also tested not specifying subnets in profile. The it correctly takes subnets var from parent module (as was always the case).

[aittam]

It works as intended, I am using it in a real word project.

[barryib]

Thanks @zimbatm

[github-actions]

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