I need to be able to conditionally create an EIP and associate it to an instance:
resource "aws_eip" "gateway" {
vpc = true
tags = {
Name = "${var.project_id}-gateway"
Project = "${var.project_id}"
user = "${var.user}"
}
}
resource "aws_eip_association" "eip_assoc_gateway" {
instance_id = aws_instance.gateway.id
allocation_id = aws_eip.gateway.id
}
resource "aws_instance" "gateway" {
...
}
Unfortunately, aws_eip and aws_eip_association don't appear to support the count attribute, so I'm not clear if this is even possible?
Any ideas?
As mentioned in comment, count is supported by all Terraform primitive resources. Example for aws_eip below:
resource "aws_eip" "eip" {
instance = "${element(aws_instance.manager.*.id,count.index)}"
count = "${var.eip_count}"
vpc = true
}
Related
I would like to create EC2 VMs with the following resource declaration using Terraform.
resource "aws_instance" "wurststand" {
for_each = toset(["bratwurst-01", "bratwurst-02", "bratwurst-03", "currywurst-01", "currywurst-02" , "hotdog-01"])
ami = "ami-0c9354388bb36c088"
instance_type = "t2.micro"
key_name = "wurststand"
tags = {
name = each.key
}
}
Now I need the public_ip addresses of all Bratwurst instances in one string. To create a group_vars file for ansible that fills a JINJA2 template again. How do I do this. I already tried to solder this with join but somehow Terraform doesn't like it.
The final result should look like this: 127.0.0.1, 127.0.0.2, 127.0.0.3.
Thank you for your help.
You need to use a for expression to extract the list of IPs from the set of aws_instance resources, and then pass that to join:
join(", ", [for i in aws_instance.wurststand : i.private_ip])
So this is my solution with which it does what I want.
resource "aws_instance" "wurststand" {
for_each = toset(["bratwurst-01", "bratwurst-02", "currywurst-01", "currywurst-02", "currywurst-03", "hotdog-01", "logstash-01"])
ami = "ami-0c9354388bb36c088"
instance_type = "t2.micro"
key_name = "wurststand"
tags = {
Name = each.key
}
}
resource "local_file" "inventory" {
content = templatefile("templates/inventory.tftpl", {
elastic = tomap({
for instance in aws_instance.wurststand:
instance.tags.Name => instance.public_ip
})
})
filename = format("%s/%s", abspath(path.root), "../ansible/inventory/inventory.cfg")
}
resource "local_file" "bratwurst_hosts_for_group_vars" {
content = templatefile("templates/bratwurst_groupvars.tftpl", {
hosts = join("\" , \"", [for i in aws_instance.wurststand: i.public_ip if contains("bratwurst", i.tags.Name)])
})
filename = format("%s/%s", abspath(path.root), "../ansible/group_vars/Bratwurst.yml")
}
Thanks a lot for your help.
I am new to terraform and I'm trying to create a VPC with multiple subnets and adding route tables to all those subnets in a for loop manner.
VPC: 10.207.0.0/16
There's number_of_subnets which will create subnets like this: 10.207.x.0/24
This code works fine:
variable "region" {
default = "us-east-1"
}
variable "availability_zone" {
default = "us-east-1a"
}
variable "cidr_block" {
default = "207"
}
variable "number_of_subnets" {
default = 5
}
provider "aws" {
region = var.region
}
resource "aws_vpc" "test_vpc" {
cidr_block = "10.${var.cidr_block}.0.0/16"
instance_tenancy = "default"
enable_dns_support = true
enable_dns_hostnames = true
tags = {
Name = "test_vpc_${var.cidr_block}"
}
}
resource "aws_subnet" "test_subnets" {
count = var.number_of_subnets
vpc_id = aws_vpc.test_vpc.id
cidr_block = "10.${var.cidr_block}.${count.index+1}.0/24" # start from x.x.1.0/24
availability_zone = var.availability_zone
map_public_ip_on_launch = false
tags = {
Name = "test_subnet_${var.cidr_block}_${count.index+1}"
}
}
Now if I try to add this code to the bottom of the same file (everything is in one file called main.tf) to get the subnets and add route table to each:
# get all subnet IDs
data "aws_subnets" "q_subnets" {
filter {
name = "vpc-id"
values = [aws_vpc.test_vpc.id]
}
}
# add route table to all subnets
resource "aws_route_table_association" "rt_assoc_subnet" {
depends_on = [aws_subnet.test_subnets]
for_each = toset(data.aws_subnets.q_subnets.ids)
subnet_id = each.value
route_table_id = aws_route_table.test_rt.id
}
and run terraform apply it will give this error:
invalid for_each argument...
The "for_each" value depends on resource attribute that cannot be deteremined until apply,...
which doesn't make scense. First create vpc, then subnet, then get all subnets...
I also tried depends_on and didn't help.
How would I write this to make it work?
Any help is appreciated.
UPDATE1:
I tried to use aws_subnet.test_subnets.*.id instead of data and it still gives depencendy error:
variable "region" {
default = "us-east-1"
}
variable "availability_zone" {
default = "us-east-1a"
}
variable "cidr_block" {
default = "207"
}
variable "number_of_subnets" {
default = 5
}
provider "aws" {
region = var.region
}
resource "aws_vpc" "test_vpc" {
cidr_block = "10.${var.cidr_block}.0.0/16"
instance_tenancy = "default"
enable_dns_support = true
enable_dns_hostnames = true
tags = {
Name = "test_vpc_${var.cidr_block}"
}
}
resource "aws_route_table" "test_rt" {
vpc_id = aws_vpc.test_vpc.id
route = []
tags = {
Name = "test_rt_${var.cidr_block}"
}
}
resource "aws_subnet" "test_subnets" {
count = var.number_of_subnets
vpc_id = aws_vpc.test_vpc.id
cidr_block = "10.${var.cidr_block}.${count.index+1}.0/24" # start from x.x.1.0/24
availability_zone = var.availability_zone
map_public_ip_on_launch = false
tags = {
Name = "test_subnet_${var.cidr_block}_${count.index+1}"
}
}
output "subnets" {
value = aws_subnet.test_subnets.*.id
}
# add route table to all subnets
resource "aws_route_table_association" "rt_assoc_subnet" {
depends_on = [aws_subnet.test_subnets]
for_each = toset(aws_subnet.test_subnets.*.id)
subnet_id = each.value
route_table_id = aws_route_table.test_rt.id
}
is there another way to pass the subnets to aws_route_table_association without getting dependency error?
Since you are using count, it is very hard to make count work with for_each. It would be better to continue using count for route table association as well. If you decide to go down that route, the only change you need is:
resource "aws_route_table_association" "rt_assoc_subnet" {
count = var.number_of_subnets
subnet_id = aws_subnet.test_subnets.*.id[count.index]
route_table_id = aws_route_table.test_rt.id
}
This will work as intended. However, if you must use for_each I would suggest defining a variable that could be used with it in all the resources you are now using count. If you really want to use for_each with the current code, then you can use the -target option [1]:
terraform apply -target=aws_vpc.test_vpc -target=aws_route_table.test_rt -target=aws_subnet.test_subnets
When running this command, this will be shown in the command output:
│ Warning: Resource targeting is in effect
│
│ You are creating a plan with the -target option, which means that the result of this plan may not represent all of the changes requested by the current
│ configuration.
│
│ The -target option is not for routine use, and is provided only for exceptional situations such as recovering from errors or mistakes, or when Terraform
│ specifically suggests to use it as part of an error message.
After the targeted resources are created, you could re-run terraform apply and it should create the route table associations.
[1] https://www.terraform.io/cli/commands/plan#target-address
Need your kind help. I am stuck with the following resource creation. Using Terraform v1.0.6
I need to create appropriate subnets dynamically in two VPCs
variables.tf
vpc_resource_networks = {
pnw-01 = [
[
{
subnet_name = "wb-01"
subnet_ip = "10.58.72.0/25"
description = "WEB01"
index = 0
},
{
subnet_name = "wb-02"
subnet_ip = "10.58.72.128/25"
description = "WEB02"
index = 1
}
],
[
{
subnet_name = "wb-01"
subnet_ip = "10.58.80.0/25"
description = "WEB01"
index = 0
},
{
subnet_name = "web-02"
subnet_ip = "10.58.72.128/25"
description = "WEB02"
index = 1
}
]
]
}
main.tf
locals {
wlb_net = element(keys(var.vpc_resource_networks), 0)
}
resource "aws_subnet" "wlb" {
count = length(module.aws_vpc_app_resource)
vpc_id = element(module.aws_vpc_app_resource.*.vpc_id, count.index)
dynamic "subnet_group" {
for_each = var.vpc_resource_networks[local.wlb_net][count.index]
content {
dynamic "subnet" {
for_each = subnet_group.value
content {
cidr_block = subnet.subnet_ip
availability_zone = element(var.azs, subnet.index)
tags = {
Name = subnet.subnet_name
}
}
}
}
}
I intend to create subnets dynamically which is var.vpc_resource_networks.pnw01[0] should be on one vpc and other index on another VPC.
The above block returns
dynamic “subnet_group” {
Blocks of type “subnet_group” are not expected here.
Please assist
Looking at the resource definition of aws_subnet, I can see that, as the error message suggests, there's no property for a "subnet_group".
There are several different resource types that are subnet groups though for different services; such as DMS, DocumentDB, DAX, Elasticache, MemoryDB, Neptune, RDS, and Redshift. Search the term "subnet_group" on the left panel within the provider page.
Perhaps an AWS expert can comment here but I believe you're trying to do two things in one motion here.
First you should create the subnets and define their ranges, then you should create subnet groups that need access to different subnets for a particular service.
Here's some more information on subnets and subnet groups.
I’m trying to write some code which would take an input structure like this:
projects = {
"project1" = {
namespaces = ["mynamespace1"]
},
"project2" = {
namespaces = ["mynamespace2", "mynamespace3"]
}
}
and provision multiple resources with for_each which would result in this:
resource "rancher2_project" "project1" {
provider = rancher2.admin
cluster_id = module.k8s_cluster.cluster_id
wait_for_cluster = true
}
resource "rancher2_project" "project2" {
provider = rancher2.admin
cluster_id = module.k8s_cluster.cluster_id
wait_for_cluster = true
}
resource "rancher2_namespace" "mynamespace1" {
provider = rancher2.admin
project_id = rancher2_project.project1.id
depends_on = [rancher2_project.project1]
}
resource "rancher2_namespace" "mynamespace2" {
provider = rancher2.admin
project_id = rancher2_project.project2.id
depends_on = [rancher2_project.project2]
}
resource "rancher2_namespace" "mynamespace3" {
provider = rancher2.admin
project_id = rancher2_project.project2.id
depends_on = [rancher2_project.project2]
}
namespaces are dependent on Projects and the generate id needs to be passed into namespace.
Is there any good way of doing this dynamically ? We might have a lot of Projects/namespaces.
Thanks for any help and advise.
The typical answer for systematically generating multiple instances of a resource based on a data structure is resource for_each. The main requirement for resource for_each is to have a map which contains one element per resource instance you want to create.
In your case it seems like you need one rancher2_project per project and then one rancher2_namespace for each pair of project and namespaces. Your current data structure is therefore already sufficient for the rancher2_project resource:
resource "rancher2_project" "example" {
for_each = var.projects
provider = rancher2.admin
cluster_id = module.k8s_cluster.cluster_id
wait_for_cluster = true
}
The above will declare two resource instances with the following addresses:
rancher2_project.example["project1"]
rancher2_project.example["project2"]
You don't currently have a map that has one element per namespace, so it will take some more work to derive a suitable value from your input data structure. A common pattern for this situation is flattening nested structures for for_each using the flatten function:
locals {
project_namespaces = flatten([
for pk, proj in var.projects : [
for nsk in proj.namespaces : {
project_key = pk
namespace_key = ns
project_id = rancher2_project.example[pk].id
}
]
])
}
resource "rancher2_namespace" "example" {
for_each = {
for obj in local.project_namespaces :
"${obj.project_key}.${obj.namespace_key}" => obj
}
provider = rancher2.admin
project_id = each.value.project_id
}
This produces a list of objects representing all of the project and namespace pairs, and then the for_each argument transforms it into a map using compound keys that include both the project and namespace keys to ensure that they will all be unique. The resulting instances will therefore have the following addresses:
rancher2_namespace.example["project1.mynamespace1"]
rancher2_namespace.example["project2.mynamespace2"]
rancher2_namespace.example["project2.mynamespace3"]
This seems to work too:
resource "rancher2_namespace" "example" {
count = length(local.project_namespaces)
provider = rancher2.admin
name = local.project_namespaces[count.index].namespace_name
project_id = local.project_namespaces[count.index].project_id
}
I have the following code and I would like to have a conditional that will only create an elastic IP if the instance is part of a public subnet (or based off of a boolean value if needed). This is the code that I currently have that works, but I want it to not create elastic IPs for resources on the private subnets:
locals {
instances_beta = {
my-ec2 = {
name = "myec2",
ami = "ami-029e27fb2fc8ce9d8",
instancetype = "t3.xlarge"
environment = "Beta",
securitygroups = [var.mysg],
subnetid = var.public-a,
elasticip = true
}
}
}
resource "aws_instance" "beta-instance" {
for_each = local.instances_beta
ami = each.value.ami
instance_type = each.value.instancetype
subnet_id = each.value.subnetid
key_name = "mykey"
vpc_security_group_ids = each.value.securitygroups
tags = {
Name = each.value.name
Environment = each.value.environment
}
}
resource "aws_eip" "beta-eip" {
for_each = local.instances_beta
instance = aws_instance.beta-instance[each.key].id
vpc = true
}
It sounds like count is the best way to do something like that, but I cannot do that as I am already using a for_each to achieve the resource creation. I was trying to do this with a nested for loop, but I cannot quite figure out how to get the syntax correct or if this is the best way to do it. For reference , the best resource I found on it was here around for_each conditionals: https://blog.gruntwork.io/terraform-tips-tricks-loops-if-statements-and-gotchas-f739bbae55f9
You can use for loop to create filtered map, for example:
for_each = {
for key, value in local.instances_beta: key => value if value.subnetid == var.public-a
}
It will filter local.instances_beta and leave items where subnetid equals var.public-a. You can adjust condition according to your needs.
More details in terraform documentation.