Add variables for parameter_group_name and parameter_group_create_on_destroy

[joshuabaird]

what

This PR adds two new variables:

• parameter_group_name
• parameter_group_create_before_destroy

why

This module doesn't currently support major version upgrades of Redis (eg, 6.x to. 7.x) because:

• Parameter groups are major-version specific, so when a user changes var.family from redis6 to redis7, Terraform needs to create a new parameter group. Without create_before_destroy, Terraform tries to first destroy the old Param group which fails because it's currently in use
• Parameter groups must have unique names across families. When Terraform tries to create a new param group for redis7, it fails because it tries to do so using the same name as the old param group.

references

• Closes aws_elasticache_parameter_group should have create_before_destroy set to true #178

[joshuabaird]

Can we get this merged? @goruha

[joshuabaird]

/test all

[aknysh]

/test all

[aknysh]

@joshuabaird thanks for the PR
Please see the errors https://github.com/cloudposse/actions/actions/runs/4376943663/jobs/7659766652

variables are not allowed in the lifecycle block. This is an annoying TF feature
We usually get around that by creating two similar resources

resource "aws_elasticache_parameter_group" "default"
  count = module.this.enabled && var.parameter_group_create_before_destroy == false ? 1 : 0

resource "aws_elasticache_parameter_group" "create_before_destroy"
  count = module.this.enabled && var.parameter_group_create_before_destroy == true ? 1 : 0

and in the outputs.tf, select one or the other by using var.parameter_group_create_before_destroy ? xxx : yyy

please also run the following commands:

make init
make github/init
make readme

and commit the changes (GitHub token has been chamged in GH workflows, and the command make github/init will update all the GH workflows in the repo)

thank you

[aknysh]

please see comments

[joshuabaird]

@joshuabaird thanks for the PR Please see the errors https://github.com/cloudposse/actions/actions/runs/4376943663/jobs/7659766652

variables are not allowed in the lifecycle block. This is an annoying TF feature We usually get around that by creating two similar resources

I see that Terratest is failing, but this code does work. I'm using it. I'll take a look at your suggestion.

[goruha]

@joshuabaird Yes. We have so issue with our test infrastructure.
I will rerun tests ASAP.

[joshuabaird]

Thinking about this more, I don't think we need to parameterize the lifecycle in the first place. I think this is easily solved by always setting create_before_destroy = true.