main.tf

locals {
  create_acl_name = coalesce(var.acl_name, var.name)
  acl_name        = var.create && var.create_acl ? aws_memorydb_acl.this[0].id : var.acl_name

  create_parameter_group_name = coalesce(var.parameter_group_name, var.name)
  parameter_group_name        = var.create && var.create_parameter_group ? aws_memorydb_parameter_group.this[0].id : var.parameter_group_name

  create_subnet_group_name = coalesce(var.subnet_group_name, var.name)
  subnet_group_name        = var.create && var.create_subnet_group ? aws_memorydb_subnet_group.this[0].id : var.subnet_group_name
}

################################################################################
# Cluster
################################################################################

resource "aws_memorydb_cluster" "this" {
  count = var.create ? 1 : 0

  name        = var.use_name_prefix ? null : var.name
  name_prefix = var.use_name_prefix ? "${var.name}-" : null
  description = var.description

  engine_version             = var.engine_version
  auto_minor_version_upgrade = var.auto_minor_version_upgrade
  port                       = var.port
  node_type                  = var.node_type
  num_shards                 = var.num_shards
  num_replicas_per_shard     = var.num_replicas_per_shard
  parameter_group_name       = local.parameter_group_name
  data_tiering               = var.data_tiering

  acl_name           = local.acl_name
  kms_key_arn        = var.kms_key_arn
  tls_enabled        = var.tls_enabled
  security_group_ids = var.security_group_ids
  subnet_group_name  = local.subnet_group_name

  maintenance_window = var.maintenance_window
  sns_topic_arn      = var.sns_topic_arn

  snapshot_name            = var.snapshot_name
  snapshot_arns            = var.snapshot_arns
  snapshot_retention_limit = var.snapshot_retention_limit
  snapshot_window          = var.snapshot_window
  final_snapshot_name      = var.final_snapshot_name

  tags = var.tags
}

################################################################################
# User(s)
################################################################################

resource "aws_memorydb_user" "this" {
  for_each = { for k, v in var.users : k => v if var.create && var.create_users }

  user_name     = each.value.user_name
  access_string = each.value.access_string

  authentication_mode {
    type      = try(each.value.type, "password")
    passwords = try(each.value.passwords, null)
  }

  tags = merge(var.tags, lookup(each.value, "tags", {}))
}

################################################################################
# ACL
################################################################################

resource "aws_memorydb_acl" "this" {
  count = var.create && var.create_acl ? 1 : 0

  name        = var.acl_use_name_prefix ? null : local.create_acl_name
  name_prefix = var.acl_use_name_prefix ? "${local.create_acl_name}-" : null

  user_names = distinct(concat([for u in aws_memorydb_user.this : u.id], var.acl_user_names))

  lifecycle {
    create_before_destroy = true
  }

  tags = merge(var.tags, var.acl_tags)
}

################################################################################
# Parameter Group
################################################################################

resource "aws_memorydb_parameter_group" "this" {
  count = var.create && var.create_parameter_group ? 1 : 0

  name        = var.parameter_group_use_name_prefix ? null : local.create_parameter_group_name
  name_prefix = var.parameter_group_use_name_prefix ? "${local.create_parameter_group_name}-" : null
  description = var.parameter_group_description
  family      = var.parameter_group_family

  dynamic "parameter" {
    for_each = var.parameter_group_parameters
    content {
      name  = parameter.value.name
      value = parameter.value.value
    }
  }

  lifecycle {
    create_before_destroy = true
  }

  tags = merge(var.tags, var.parameter_group_tags)
}

################################################################################
# Subnet Group
################################################################################

resource "aws_memorydb_subnet_group" "this" {
  count = var.create && var.create_subnet_group ? 1 : 0

  name        = var.subnet_group_use_name_prefix ? null : local.create_subnet_group_name
  name_prefix = var.subnet_group_use_name_prefix ? "${local.create_subnet_group_name}-" : null
  description = var.subnet_group_description
  subnet_ids  = var.subnet_ids

  lifecycle {
    create_before_destroy = true
  }

  tags = merge(var.tags, var.subnet_group_tags)
}