feat: Support Valkey

[magreenbaum]

Description

Support Valkey.

As a note, there is a bug in the provider where aws_elasticache_cluster doesn't support Valkey.

Motivation and Context

Closes: #25
hashicorp/terraform-provider-aws#39972

Breaking Changes

No.

How Has This Been Tested?

• I have updated at least one of the examples/* to demonstrate and validate my change(s)
• I have tested and validated these changes using one or more of the provided examples/* projects

• I have executed pre-commit run -a on my pull request

[BramRoets]

@magreenbaum I'm unable to deploy valkey using your changes. Using the following code, I get a validation error:

module "elasticache" {
  source = "github.com/magreenbaum/terraform-aws-elasticache?ref=8131ae92fd7d9131d602760af0c92adf9db74a88"

  cluster_id               ="${var.name}-valkey"
  create_cluster           = true
  create_replication_group = false

  engine_version = "7.2"
  engine         = "valkey"
  node_type      = "cache.t4g.micro"


  vpc_id = module.vpc.vpc_id
  security_group_rules = {
    ingress_vpc = {
      cidr_ipv4 = module.vpc.vpc_cidr_block
    }
  }

  subnet_ids = module.vpc.private_subnets

  create_parameter_group = true
  parameter_group_family = "valkey7"
}

Error:

│ Error: expected engine to be one of ["memcached" "redis"], got valkey
│
│   with module.elasticache.aws_elasticache_cluster.this[0],
│   on .terraform/modules/elasticache/main.tf line 23, in resource "aws_elasticache_cluster" "this":
│   23:   engine                     = local.in_replication_group ? null : var.engine```

[magreenbaum]

@magreenbaum I'm unable to deploy valkey using your changes. Using the following code, I get a validation error:

module "elasticache" {
  source = "github.com/magreenbaum/terraform-aws-elasticache?ref=8131ae92fd7d9131d602760af0c92adf9db74a88"

  cluster_id               ="${var.name}-valkey"
  create_cluster           = true
  create_replication_group = false

  engine_version = "7.2"
  engine         = "valkey"
  node_type      = "cache.t4g.micro"


  vpc_id = module.vpc.vpc_id
  security_group_rules = {
    ingress_vpc = {
      cidr_ipv4 = module.vpc.vpc_cidr_block
    }
  }

  subnet_ids = module.vpc.private_subnets

  create_parameter_group = true
  parameter_group_family = "valkey7"
}

Error:

│ Error: expected engine to be one of ["memcached" "redis"], got valkey
│
│   with module.elasticache.aws_elasticache_cluster.this[0],
│   on .terraform/modules/elasticache/main.tf line 23, in resource "aws_elasticache_cluster" "this":
│   23:   engine                     = local.in_replication_group ? null : var.engine```

There is a bug in the provider currently for creating valkey clusters: hashicorp/terraform-provider-aws#39905

[bryantbiggs]

we should wait for the upstream provider bug to be resolved first, no?

[magreenbaum]

we should wait for the upstream provider bug to be resolved first, no?

@bryantbiggs we can, but I figured this way those that want to use valkey for replication groups and serverless can do so in the mean time since the bug only affects aws_elasticache_cluster resource.

[phene]

Awesome. Please lets merge this regardless of the provider bug.

[bryantbiggs]

I've pinged a few folks - I don't want to add support for something that is known to not work

[bryantbiggs]

FYI - hashicorp/terraform-provider-aws#39972 (comment)

So we shouldn't add support for it here for cache clusters (serverless and replication groups do support it and we can support that as well)

[magreenbaum]

Added a conditional to not create clusters if engine is valkey.

[eahangari-8x8]

Hi All, any update on Valkey support?

[bryantbiggs]

I will take a look today - it's re:Invent season plus the holiday season so be patient 😅

[bryantbiggs]

thank you @magreenbaum, another phenomenal contribution 🎉

[antonbabenko]

This PR is included in version 1.4.0 🎉

[taer]

This line seems to prevent valkey creation still
https://github.com/terraform-aws-modules/terraform-aws-elasticache/blob/master/main.tf#L8

  # elasticache clusters currently do not support engine type valkey
  # TODO: remove this local `create_cluster` conditional once this bug is addressed:
  # https://github.com/hashicorp/terraform-provider-aws/issues/39905
  create_cluster = var.create_cluster && var.engine != "valkey" ? true : false

when I put valkey in for the engine with the latest module, I get a delete of my cluster. Should this above line vanish now? @magreenbaum

[bryantbiggs]

Valkey is not supported on clusters, only replication groups

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