Using multiple module outputs to a new module in Terraform - terraform

I have seen some codes with same intention but somehow I couldnt make it work.
I have two different modules,
subnet - Where I'm creating two subnets where subnet name is provided in tfvars
nsg - Where I'm creating two nsg where nsg name is provided in tfvars
And I output the created subnet id's and nsg_ids to my main.tf from both module
What I'm trying to do is to associate each subnets to each nsg's like
subnet1 to nsg1
subnet2 to nsg2
Main.tf
module "nsg" {
source = "./Modules/NSGConfig"
nsglist = var.nsglist
resource_group_name = azurerm_resource_group.resource_group.name
location = azurerm_resource_group.resource_group.location
nsg = tomap(
{
for k, subnet_id in module.SUBNETS.subnet_ids : k =>
{
subnet_id = subnet_id
}
}
)
}
NSG.tf (only including association part)
resource "azurerm_subnet_network_security_group_association" "nsg_association" {
for_each=var.nsg
subnet_id = each.value.subnet_id
network_security_group_id = azurerm_network_security_group.nsg[*].nsg_id #wont work
}
variable.tf (NSG module)
variable "nsg" {
type = map(object({
subnet_id = string
}))
}
I tried to nest the for (in main.tf) to include the output from nsgid but failed.
Ps. I'm really new to terraform
Main.tfvars
RGlocation = "westus"
RGname = "TEST-RG1-TERRAFORM"
VNETname = "TEST-VNET-TERRAFORM"
address_space = "10.0.0.0/16"
Subnetlist = {
"s1" = { name = "TESTSUBNET1-TERRAFORM", address = "10.0.1.0/24" },
"s2" = { name = "TESTSUBNET2-TERRAFORM", address = "10.0.2.0/24" },
"s3" = { name = "TESTSUBNET3-TERRAFORM", address = "10.0.3.0/24" }
}
niclist = {
"s1" = { name = "TESTNIC1-TERRAFORM" },
"s2" = { name = "TESTNIC2-TERRAFORM" },
"s3" = { name = "TESTNIC3-TERRAFORM" }
}
nsglist = {
"s1" = { name = "TESTNSG1-TERRAFORM" },
"s2" = { name = "TESTNSG1-TERRAFORM" },
"s3" = { name = "TESTNSG1-TERRAFORM" }
}
--- Update 2
Module output from the subnet module and NSG module is as below
Outputs:
nsg_id = tomap({
"s1" = "./resourceGroups/TEST-RG1-TERRAFORM/providers/Microsoft.Network/networkSecurityGroups/TESTNSG1-TERRAFORM"
"s2" = "./resourceGroups/TEST-RG1-TERRAFORM/providers/Microsoft.Network/networkSecurityGroups/TESTNSG1-TERRAFORM"
"s3" = "./resourceGroups/TEST-RG1-TERRAFORM/providers/Microsoft.Network/networkSecurityGroups/TESTNSG1-TERRAFORM"
})
sub_id = tomap({
"s1" = "./resourceGroups/TEST-RG1-TERRAFORM/providers/Microsoft.Network/virtualNetworks/SACHIN-TEST-VNET-TERRAFORM/subnets/TESTSUBNET1-TERRAFORM"
"s2" = "./resourceGroups/TEST-RG1-TERRAFORM/providers/Microsoft.Network/virtualNetworks/SACHIN-TEST-VNET-TERRAFORM/subnets/TESTSUBNET2-TERRAFORM"
"s3" = "./resourceGroups/TEST-RG1-TERRAFORM/providers/Microsoft.Network/virtualNetworks/SACHIN-TEST-VNET-TERRAFORM/subnets/TESTSUBNET3-TERRAFORM"
})

Related

Multiple Vnets and subnets using terraform modules

I am new to terraform and I am trying to create module for multiple vnets and under that multiple subnets
I am able to create multiple vnets using the module but I am facing issue in creating multiple subnets on one or more of the vnets created.
Below is my code for the module and as well as main.tf
network resources module/main.tf
data "azurerm_resource_group" "network" {
name = var.resource_group_name
}
resource "azurerm_virtual_network" "vnets" {
count = length(var.vnet_names)
name = var.vnet_names[count.index]
resource_group_name = data.azurerm_resource_group.network.name
location = var.vnet_location != null ? var.vnet_location : data.azurerm_resource_group.network.location
address_space = [var.vnet_adress_spaces[count.index]]
}
network resources module/variables.tf
variable "vnet_names" {
description = "Name of the vnets to be created"
type = list(string)
default = ["vnet1","vnet2","vnet3"]
}
variable "vnet_adress_spaces" {
description = "Name of the vnets to be created"
type = list(string)
default = ["192.168.0.0/16" ,"10.0.0.0/16","10.80.0.0/16"]
}
variable "resource_group_name" {
description = "Name of the resource group to be imported."
type = string
}
variable "vnet_location" {
description = "The location of the vnet to create. Defaults to the location of the resource group."
type = string
default = null
}
variable "subnet_names" {
description = "The list of subnets which needs to be created"
type = list(list(string))
default = [[],["subnet1_vnet1","subnet2_vnet1"],["subnet1_vnet3","subnet2_vnet3","subnet3_vnet3"]]
}
variable "subnet_addresses" {
description = "The list of subnets which needs to be created"
type = list(list(string))
default = [[],["10.0.2.0/24","10.0.0.0/24"],["10.80.2.0/24","10.80.1.0/24","10.80.0.0/24"]]
}
main.tf
terraform {
required_providers {
azurerm = {
source = "hashicorp/azurerm"
version = "=2.98.0"
}
}
}
# Configure the Microsoft Azure Provider
provider "azurerm" {
features {}
}
resource "azurerm_resource_group" "rg1" {
name = "rg1"
location = "West Europe"
}
module network {
source = "./network_resources"
resource_group_name = azurerm_resource_group.rg1.name
}
3 vnets are successfully created but I am facing issue in writing subnet creation as mentioned in variables.tf
Please can you help me with that or suggest a better way of implementing this
Output.tf of module
output "vnet_names" {
description = "The name of the virtual networks"
value = {for k, v in azurerm_virtual_network.vnets: k => v.name}
}
output "vnet_addresses" {
description = "The name of the virtual networks"
value = {for k, v in azurerm_virtual_network.vnets: k => v.address_space}
}
output "subnet_names" {
description = "The name of the subnets"
value = {for k, v in azurerm_subnet.subnets: k => v.name}
}
output "subnet_addresses" {
description = "The name of the subnet addresses"
value = {for k, v in azurerm_subnet.subnets: k => v.address_prefixes}
}
output "subnet_ids" {
description = "The name of the subnet addresses"
value = {for k, v in azurerm_subnet.subnets: k => v.id}
}
When I am taking the subnet value same for two vnets as per the updated variables.tf
vnets = {
"mel-dev-identity-vnet01" = {
address_space = "10.0.0.0/16",
subnets = [
{
subnet_name = "subnet-mel-AD-dev"
subnet_address = "10.0.2.0/24"
service_endpoints = []
},
{
subnet_name = "subnet-mel-okt-dev"
subnet_address = "10.0.0.0/24"
service_endpoints = []
},
{
subnet_name = "GatewaySubnet"
subnet_address = "10.0.0.0/26"
service_endpoints = []
},
]
},
"mel-dev-identity-vnet02" = {
address_space = "10.80.0.0/16"
subnets = [
{
subnet_name = "subnet-syd-AD-dev"
subnet_address = "10.80.2.0/24"
service_endpoints = []
},
{
subnet_name = "subnet-syd-okt-dev"
subnet_address = "10.80.1.0/24"
service_endpoints = []
},
{
subnet_name = "GatewaySubnet"
subnet_address = "10.80.0.0/26"
service_endpoints = []
},
]
}
}
I am getting the below error:
│ Error: Duplicate object key
│
│ on network_resources\locals.tf line 11, in locals:
│ 11: subnets = { for subnet in local.subnets_flatlist : subnet.subnet_name => subnet }
│ ├────────────────
│ │ subnet.subnet_name is "GatewaySubnet"
│
│ Two different items produced the key "GatewaySubnet" in this 'for' expression. If duplicates are expected, use the
│ ellipsis (...) after the value expression to enable grouping by key.
I see two issues in your code:
You store attributes (e.g. subnet_name, subnet_addressed) of the same resources in different variables of type list or nested list.
This way you have to ensure consistency across the different variables manually which can become tedious and error prone. Imagine you want to add a third subnet to vnet bupavnet2. You have to make sure that you insert the new name and subnet at the corresponding positions in two nested lists.
BTW: Is it intended that the subnets in vnet bupavnet2 are named subnet#-bupavnet1 ? See what I mean ??? :)
In order to create multiple subnets in multiple vnets dynamically, you would need a nested loop which iterates over the vnets in the outer loop and across the subnets in the inner loop. Terraform, however, does not support nested for_each loops on resource level.
One way to overcome the first issue is to use complex types like objects or maps in order to make the relationship between the attributes of a resource explicit. This way it would be easy to spot the naming issue of the subnets in bupavnet2. If you want to add an additional subnet, you just need to add an additional object to the subnets list.
variable "vnets" {
type = map(object({
address_space = string
subnets = list(object({
subnet_name = string
subnet_address = string
}))
}))
default = {
"bupavnet1" = {
address_space = "192.168.0.0/16",
subnets = []
},
"bupavnet2" = {
address_space = "10.0.0.0/16",
subnets = [
{
subnet_name = "subnet1_bupavnet1"
subnet_address = "10.0.2.0/24"
},
{
subnet_name = "subnet2_bupavnet1"
subnet_address = "10.0.0.0/24"
}
]
},
"bupavnet3" = {
address_space = "10.80.0.0/16"
subnets = [
{
subnet_name = "subnet1_bupavnet3"
subnet_address = "10.80.2.0/24"
},
{
subnet_name = "subnet2_bupavnet3"
subnet_address = "10.80.1.0/24"
},
{
subnet_name = "subnet3_bupavnet3"
subnet_address = "10.80.0.0/24"
},
]
}
}
}
In succession, the creation of the vnets would change to
resource "azurerm_virtual_network" "vnets" {
for_each = var.vnets
name = each.key
resource_group_name = data.azurerm_resource_group.network.name
location = var.vnet_location != null ? var.vnet_location : data.azurerm_resource_group.network.location
address_space = [each.value.address_space]
}
Now let's have a look how to tackle the nested for loop issue. In Terraform you would address this by flattening the nested structure which we defined above. In the first step we create a flat list of objects representing the subnets to be created. So our variable subnets_flatlist has the type tuple of objects.
Unfortunately the for_each argument in Terraform requires the type map or set of strings. So we need a second step to create a map out of our flat list.
locals {
subnets_flatlist = flatten([for key, val in var.vnets : [
for subnet in val.subnets : {
vnet_name = key
subnet_name = subnet.subnet_name
subnet_address = subnet.subnet_address
}
]
])
subnets = { for subnet in local.subnets_flatlist : subnet.subnet_name => subnet }
}
Once we created our helper structures we can iterate over the subnets map and create the subnet resources:
resource "azurerm_subnet" "subnets" {
for_each = local.subnets
name = each.value.subnet_name
resource_group_name = data.azurerm_resource_group.network.name
virtual_network_name = azurerm_virtual_network.vnets[each.value.vnet_name].name
address_prefixes = [each.value.subnet_address]
}

How do I loop through te below given variable in terraform

I am trying to create vnets for multiple environments using one single variable. I am not quite sure if it is possible. My variable is given below
azure_vnets = {
Prod = [
{
cidr = "10.10.0.0/24"
vnet_name = "prod-vnet1"
dns = "10.10.0.1"
rg = "prodrg1"
location = "eastus"
},
{
cidr = "10.10.1.0/24"
vnet_name = "prod-vnet2"
dns = "10.10.0.2"
rg = "prodrg2"
location = "eastus"
}
],
nonProd = [
{
cidr = "10.10.0.0/24"
vnet_name = "nonprod-vnet1"
dns = "10.10.0.1"
rg = "nonprodrg1"
location = "eastus"
},
{
cidr = "10.10.1.0/24"
vnet_name = "nonprod-vnet2"
dns = "10.10.0.2"
rg = "nonprodrg2"
location = "eastus"
}
]
}
So as to create multiple vnets from this
resource "azurerm_virtual_network" "this" {
for_each = xxx
name = each.xxx
xxxx
xxx
}
You have to flatten it first:
locals {
flat_azure_vnets = merge([
for env_name, env_vn_list in var.azure_vnets:
{
for idx, env_vn in env_vn_list:
"${env_name}-${idx}" => env_vn
}
]...)
}
then you use it:
resource "azurerm_virtual_network" "this" {
for_each = local.flat_azure_vnets
name = each.value["vnet_name"]
xxxx
xxx
}

Referencing a created subnet and associate it with a given EIP for a NLB (aws provider)

I'm trying to parametrize the creation of a NLB, and provision in the same plan the necessary public subnets.
The subnets are specified as a variable of the plan:
variable "nlb_public_subnets" {
type = list(object({
name = string
network_number = number
availability_zone = string
elastic_ip = string
}))
default = [
{
name = "sftp_sub_A"
network_number = 1
availability_zone = "eu-west-1a"
elastic_ip = "X.Y.Z.T"
},
{
name = "sftp_sub_B"
network_number = 2
availability_zone = "eu-west-1b"
elastic_ip = "XX.YY.ZZ.TT"
}
]
}
variable "common_tags" {
description = "A map containing the common tags to apply to all resources"
type = map(string)
default = {}
}
locals {
vpc_id = "dummy"
base_cidr = "10.85.23.0/24"
publicSubnets = { for s in var.nlb_public_subnets :
s.name => {
name = s.name
cidr_block = cidrsubnet(var.base_public_subnet_cidr_block, 6,
s.network_number )
availability_zone = s.availability_zone
elastic_ip = s.elastic_ip
}
}
}
I'm specifying a name, a network number (to compute the cidr block), an availability zone, and an elastic IP to map to when creating the NLB.
Here I'm creating the subnets:
#Comment added after solution was given
#This will result in a Map indexed by subnet.name provided in var.nlb_public_subnets
resource "aws_subnet" "sftp_nlb_subnets" {
for_each = { for subnet in local.publicSubnets :
subnet.name => subnet
}
cidr_block = each.value.cidr_block
vpc_id = local.vpc_id
availability_zone = each.value.availability_zone
tags = {
Name = each.key
Visibility = "public"
Purpose = "NLB"
}
}
Now I need to create my NLB, and this is where I'm struggling on how to associate the freshly created subnets with the Elastic IP provided in the configuration:
resource "aws_lb" "sftp" {
name = var.name
internal = false
load_balancer_type = "network"
subnets = [for subnet in aws_subnet.sftp_nlb_subnets: subnet.id]
enable_deletion_protection = true
tags = merge(var.common_tags,{
Name=var.name
})
dynamic "subnet_mapping" {
for_each = aws_subnet.sftp_nlb_subnets
content {
subnet_id = subnet_mapping.value.id
allocation_id = ????Help???
}
}
}
Could I somehow look up the configuration object with the help of the subnet name in the tags?
UPDATE1
Updated the dynamic block, as it had a typo.
UPDATE2
#tmatilai nailed the answer!
Here's the modified aws_lb block:
#
#This will result in a Map indexed by subnet.name provided in var.nlb_public_subnets
data "aws_eip" "nlb" {
for_each = local.publicSubnets
public_ip = each.value.elastic_ip
}
resource "aws_lb" "sftp" {
name = var.name
internal = false
load_balancer_type = "network"
subnets = [for subnet in aws_subnet.sftp_nlb_subnets : subnet.id]
enable_deletion_protection = true
tags = merge(var.common_tags, {
Name = var.name
})
dynamic "subnet_mapping" {
#subnet_mapping.key will contain subnet.name, so we can use it to access the Map data.aws_eip.nlb (also indexed by subnet.name) to get the eip allocation_id
for_each = aws_subnet.sftp_nlb_subnets
content {
subnet_id = subnet_mapping.value.id
allocation_id = data.aws_eip.nlb[subnet_mapping.key].id
}
}
}
The trick is to realize that both aws_subnet.sftp_nlb_subnets and data.aws_eip.nlb are a Map, indexed by the key of local.publicSubnets. This allows us to use this common key (the subnet name) in the map aws_subnet.sftp to look up information in the data (data.aws_eip.nlb) obtained from the original input, local.publicSubnets.
Thanks. This is a neat trick.
Passing the IP address of the elastic IPs sounds strange. If you create the EIPs elsewhere, why not pass the (allocation) ID of them instead?
But with this setup, you can get the allocation ID with the aws_eip data source:
data "aws_eip" "nlb" {
for_each = local.publicSubnets
public_ip = each.value.elastic_ip
}
resource "aws_lb" "sftp" {
# ...
dynamic "subnet_mapping" {
for_each = aws_subnet.sftp_nlb_subnets
content {
subnet_id = subnet_mapping.value.id
allocation_id = data.aws_eip.nlb[subnet_mapping.key].id
}
}
}
But maybe it would make more sense to create the EIPs also here. For example something like this:
resource "aws_eip" "nlb" {
for_each = local.publicSubnets
vpc = true
}
resource "aws_lb" "sftp" {
# ...
dynamic "subnet_mapping" {
for_each = aws_subnet.sftp_nlb_subnets
content {
subnet_id = subnet_mapping.value.id
allocation_id = aws_eip.nlb[subnet_mapping.key].id
}
}
}

Terraform: How to iterate the name or another variable in a resource group when the variable being passed in is a list of a list of maps?

This is what I have so far, while I can pull a specific list or name using the local variables, I am having trouble transitioning this into the resource group. First, am I attempting this the right way? If not how can I iterate on the name for the subnet so that the subnets belonging to the respective vnet map are added?
variable "vnets" {
default = [
{
vnet_name = "test-vnet"
address_space = "10.250.0.0"
network_size = 16
subnets = [
{
name = "first-subnet"
network_security_group = "first-nsg"
security_group_rules = [
{
name = "first-sg"
priority = 100
}
]
},
{
name = "second-subnet"
network_security_group = "second-nsg"
security_group_rules = [
{
name = "second-sg"
priority = 100
}
]
}
]
}
]
}
locals {
subnet_names = {
for vnet in var.vnets[*]:
(vnet.vnet_name) => vnet.subnets[*].name
}
security_group_names = flatten(var.vnets[*].subnets[*].security_group_rules[*].name)
}
resource "azurerm_subnet" "subnets" {
count = length(var.vnets)
#??? name = locals.subnet_names[count.index].subnets.name
resource_group_name = data.azurerm_resource_group.network_group.name
virtual_network_name = azurerm_virtual_network.vnets.*.name
address_prefixes = ["10.0.1.0/24"]
}
I think the easiest would be to flatten your subnet_names:
locals {
subnet_names = {
for vnet in var.vnets[*]:
(vnet.vnet_name) => vnet.subnets[*].name
}
security_group_names = flatten(var.vnets[*].subnets[*].security_group_rules[*].name)
# uniqueness of "${vnet}-${subnet}" pairs is assumed. it will not work
# if the pairs are not unique
subnet_names_flat = merge([
for vnet, subnets in local.subnet_names:
{
for subnet in subnets:
"${vnet}-${subnet}" => {name = vnet, subnet = subnet}
}
]...)
}
Which will result in subnet_names_flat being:
{
"test-vnet-first-subnet" = {
"name" = "test-vnet"
"subnet" = "first-subnet"
}
"test-vnet-second-subnet" = {
"name" = "test-vnet"
"subnet" = "second-subnet"
}
}
Then your azurerm_subnet.subnets could as below. However, I'm not able to verify correctness of your the azurerm_subnet, thus you may need to change it further. But the idea is to iterate over local.subnet_names_flat, which makes the for_each very easy to use:
resource "azurerm_subnet" "subnets" {
for_each = local.subnet_names_flat
name = each.value.subnet
resource_group_name = data.azurerm_resource_group.network_group.name
virtual_network_name = each.value.vnet
address_prefixes = ["10.0.1.0/24"]
}

Terraform for_each if value exists in object

I would like to dynamically create some subnets and route tables from a .tfvars file, and then link each subnet to the associated route table if specified.
Here is my .tfvars file:
vnet_spoke_object = {
specialsubnets = {
Subnet_1 = {
name = "test1"
cidr = ["10.0.0.0/28"]
route = "route1"
}
Subnet_2 = {
name = "test2"
cidr = ["10.0.0.16/28"]
route = "route2"
}
Subnet_3 = {
name = "test3"
cidr = ["10.0.0.32/28"]
}
}
}
route_table = {
route1 = {
name = "route1"
disable_bgp_route_propagation = true
route_entries = {
re1 = {
name = "rt-rfc-10-28"
prefix = "10.0.0.0/28"
next_hop_type = "VirtualAppliance"
next_hop_in_ip_address = "10.0.0.10"
}
}
}
route2 = {
name = "route2"
disable_bgp_route_propagation = true
route_entries = {
re1 = {
name = "rt-rfc-10-28"
prefix = "10.0.0.16/28"
next_hop_type = "VirtualAppliance"
next_hop_in_ip_address = "10.0.0.10"
}
}
}
}
...and here is my build script:
provider "azurerm" {
version = "2.18.0"
features{}
}
variable "ARM_LOCATION" {
default = "uksouth"
}
variable "ARM_SUBSCRIPTION_ID" {
default = "asdf-b31e023c78b8"
}
variable "vnet_spoke_object" {}
variable "route_table" {}
module "names" {
source = "./nbs-azure-naming-standard"
env = "dev"
location = var.ARM_LOCATION
subId = var.ARM_SUBSCRIPTION_ID
}
resource "azurerm_resource_group" "test" {
name = "${module.names.standard["resource-group"]}-vnet"
location = var.ARM_LOCATION
}
resource "azurerm_virtual_network" "test" {
name = "${module.names.standard["virtual-network"]}-test"
location = var.ARM_LOCATION
resource_group_name = azurerm_resource_group.test.name
address_space = ["10.0.0.0/16"]
}
resource "azurerm_subnet" "test" {
for_each = var.vnet_spoke_object.specialsubnets
name = "${module.names.standard["subnet"]}-${each.value.name}"
resource_group_name = azurerm_resource_group.test.name
virtual_network_name = azurerm_virtual_network.test.name
address_prefixes = each.value.cidr
}
resource "azurerm_route_table" "test" {
for_each = var.route_table
name = "${module.names.standard["route-table"]}-${each.value.name}"
location = var.ARM_LOCATION
resource_group_name = azurerm_resource_group.test.name
disable_bgp_route_propagation = each.value.disable_bgp_route_propagation
dynamic "route" {
for_each = each.value.route_entries
content {
name = route.value.name
address_prefix = route.value.prefix
next_hop_type = route.value.next_hop_type
next_hop_in_ip_address = contains(keys(route.value), "next_hop_in_ip_address") ? route.value.next_hop_in_ip_address: null
}
}
}
That part works fine in creating the vnet/subnet/route resources, but the problem I face is to dynamically link each subnet to the route table listed in the .tfvars. Not all the subnets will have a route table associated with it, thus it will need to only run IF the key/value route is listed.
resource "azurerm_subnet_route_table_association" "test" {
for_each = {
for key, value in var.vnet_spoke_object.specialsubnets:
key => value
if value.route != null
}
lifecycle {
ignore_changes = [
subnet_id
]
}
subnet_id = azurerm_subnet.test[each.key].id
route_table_id = azurerm_route_table.test[each.key].id
}
The error I face with the above code is:
Error: Unsupported attribute
on main.tf line 65, in resource "azurerm_subnet_route_table_association" "test":
65: if value.route != null
This object does not have an attribute named "route".
I have tried various ways with no success, and I'm at a loss here and would appreciate any guidance posisble.
Based on your scenario, I'm guessing vnet_spoke_object in input looks like this:
vnet_spoke_object = {
specialsubnets = {
subnetA = {
cidr = "..."
}
subnetB = {
cidr = "..."
route = "..."
}
}
}
The problem with that is that a missing route entry doesn't resolve to null, it causes a panic or crash. You'd need to write your input like this (with explicit nulls):
vnet_spoke_object = {
specialsubnets = {
subnetA = {
cidr = "..."
route = null
}
subnetB = {
cidr = "..."
route = "..."
}
}
}
Or lookup route by name and provide a null default in your for map generator expression like this:
for_each = {
for key, value in var.vnet_spoke_object.specialsubnets:
key => value
if lookup(value, "route", null) != null
}

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