为每个地形使用在单独的AZ中创建不同的EC2实例

Question

我正在尝试使用terraform在不同的AZ中部署不同的EC2实例。然后，我将EC2实例所在的子网与NAT网关关联到路由表。我陷入了将子网与路由表上的nat网关相关联的困境。下面是我的代码和错误。任何建议都会有帮助。

resource "aws_instance" "private" {
for_each      = var.priv_subnet
ami           = var.ec2_amis[var.region]
instance_type = each.key
key_name      = aws_key_pair.main.key_name
subnet_id     = aws_subnet.private[each.key].id
tags = {
Name = each.value.tag
}
}
resource "aws_route_table" "nat" {
for_each = var.pub_subnet
vpc_id   = aws_vpc.main.id
route {
cidr_block     = "0.0.0.0/0"
nat_gateway_id = aws_nat_gateway.main[each.key].id
}
tags = {
Name = "${var.vpc_tags}_${each.key}_PrivRT"
}
}
resource "aws_route_table_association" "nat" {
for_each       = aws_subnet.private
route_table_id = aws_route_table.nat[each.key].id
subnet_id      = each.value.id
}
resource "aws_subnet" "private" {
for_each                = var.priv_subnet
vpc_id                  = aws_vpc.tableau.id
cidr_block              = cidrsubnet(aws_vpc.main.cidr_block, 8, each.value.subnet)
availability_zone       = each.value.availability_zone
map_public_ip_on_launch = false
tags = {
Name = "PrivSub-${each.value.availability_zone}"
}
}
resource "aws_eip" "main" {
for_each = aws_subnet.public
vpc      = true
lifecycle {
create_before_destroy = true
}
}
resource "aws_nat_gateway" "tableau" {
for_each      = aws_subnet.public
subnet_id     = each.value.id
allocation_id = aws_eip.main[each.key].id
}
resource "aws_subnet" "public" {
for_each                = var.pub_subnet
vpc_id                  = aws_vpc.main.id
cidr_block              = cidrsubnet(aws_vpc.main.cidr_block, 8, each.value)
availability_zone       = each.key
map_public_ip_on_launch = true
tags = {
Name = "PubSub-${each.key}"
}
}

变量

variable "priv_subnet" {

type = map(object({
availability_zone = string
subnet            = string
tag               = string
}))
default = {
"m5.2xlarge" = {
availability_zone = "us-west-2a"
subnet            = 4
tag               = "Primary"
}
"m5.4xlarge" = {
availability_zone = "us-west-2b"
subnet            = 5
tag               = "Worker1"
}
"m5.4xlarge" = {
availability_zone = "us-west-2c"
subnet            = 6
tag               = "Worker2"
}
}
}
variable "pub_subnet" {
default = {
"us-west-2a" = 1
"us-west-2b" = 2
"us-west-2c" = 3
}
}

错误

Error: Invalid index
on vpc.tf line 99, in resource "aws_route_table_association" "nat":
99:   route_table_id = aws_route_table.nat[each.key].id
|----------------
| aws_route_table.nat is object with 3 attributes
| each.key is "m5.2xlarge"
The given key does not identify an element in this collection value.

Error: Invalid index
on vpc.tf line 99, in resource "aws_route_table_association" "nat":
99:   route_table_id = aws_route_table.nat[each.key].id
|----------------
| aws_route_table.nat is object with 3 attributes
| each.key is "m5.4xlarge"
The given key does not identify an element in this collection value.

我理解错误消息，但不确定如何将路由适当地分配给该路由表。

Answer 1

aws_route_table_association中的each.key将是来自priv_subnet的实例类型，例如m5.2xlarge。但是，aws_route_table.nat密钥将是来自var.pub_subnet的AZ名称，例如us-east-1a。

显然，这是行不通的。克服此问题的一种方法是修改priv_subnet变量，使其使用子网名称作为关键字，而不是实例类型。更改可能需要对代码进行进一步更改。

variable "priv_subnet" {
type = map(object({
instance_type     = string
subnet            = string
tag               = string
}))
default = {
"us-west-2a" = {
instance_type = "m5.2xlarge"
subnet            = 4
tag               = "Primary"
}
"us-west-2b" = {
instance_type     = "m5.4xlarge"
subnet            = 5
tag               = "Worker1"
}
"us-west-2c" = {
instance_type     = "m5.4xlarge"
subnet            = 6
tag               = "Worker2"
}
}
}

这样，var.pub_subnet和var.priv_subnet之间就有了一对一的关系，在我看来，这将简化事情。