I have a tf data resource defined.
data "aws_security_group" "this_sg" {
filter {
name = "group-name"
values = ["this_sg"]
}
vpc_id = "vpc-12345678"
}
I can pull out common arguments listed from here fine.
https://www.terraform.io/docs/providers/aws/r/security_group.html#name
${data.aws_security_group.this_sg.name}
${data.aws_security_group.this_sg.id}
but i can't pull the egress map
${data.aws_security_group.this_sg.egress}
my intention is to grab the list of cidr_blocks from within the egress map, likely through some horrendous mix of interpolations. But the egress argument can't seem to be pulled at all.
(i've checked the aws console egress cidr values are there)
Error: Error running plan: 1 error(s) occurred:
* Resource 'data.aws_security_group.this_sg' does not have attribute 'egress' for variable 'data.aws_security_group.this_sg.egress'
some ideas or work arounds would be much appreciated.
Related
terraform version 0.11.13
Error: Error refreshing state: 1 error(s) occurred:
data.aws_subnet.private_subnet: data.aws_subnet.private_subnet: value of 'count' cannot be computed
VPC code generated the error above:
resources.tf
data "aws_subnet_ids" "private_subnet_ids" {
vpc_id = "${module.vpc.vpc_id}"
}
data "aws_subnet" "private_subnet" {
count = "${length(data.aws_subnet_ids.private_subnet_ids.ids)}"
#count = "${length(var.private-subnet-mapping)}"
id = "${data.aws_subnet_ids.private_subnet_ids.ids[count.index]}"
}
Change the above code to use count = "${length(var.private-subnet-mapping)}", I successfully provisioned the VPC. But, the output of vpc_private_subnets_ids is empty.
vpc_private_subnets_ids = []
Code provisioned VPC, but got empty list of vpc_private_subnets_ids:
resources.tf
data "aws_subnet_ids" "private_subnet_ids" {
vpc_id = "${module.vpc.vpc_id}"
}
data "aws_subnet" "private_subnet" {
#count = "${length(data.aws_subnet_ids.private_subnet_ids.ids)}"
count = "${length(var.private-subnet-mapping)}"
id = "${data.aws_subnet_ids.private_subnet_ids.ids[count.index]}"
}
outputs.tf
output "vpc_private_subnets_ids" {
value = ["${data.aws_subnet.private_subnet.*.id}"]
}
The output of vpc_private_subnets_ids:
vpc_private_subnets_ids = []
I need the values of vpc_private_subnets_ids. After successfully provisioned VPC use the line, count = "${length(var.private-subnet-mapping)}", I changed code back to count = "${length(data.aws_subnet_ids.private_subnet_ids.ids)}". terraform apply, I got values of the list vpc_private_subnets_ids without above error.
vpc_private_subnets_ids = [
subnet-03199b39c60111111,
subnet-068a3a3e76de66666,
subnet-04b86aa9dbf333333,
subnet-02e1d8baa8c222222
......
]
I cannot use count = "${length(data.aws_subnet_ids.private_subnet_ids.ids)}" when I provision VPC. But, I can use it after VPC provisioned. Any clue?
The problem here seems to be that your VPC isn't created yet and so the data "aws_subnet_ids" "private_subnet_ids" data source read must wait until the apply step, which in turn means that the number of subnets isn't known, and thus the number of data "aws_subnet" "private_subnet" instances isn't predictable and Terraform returns this error.
If this configuration is also the one responsible for creating those subnets then the better design would be to refer to the subnet objects directly. If your module.vpc is also the module creating the subnets then I would suggest to export the subnet ids as an output from that module. For example:
output "subnet_ids" {
value = "${aws_subnet.example.*.id}"
}
Your calling module can then just get those ids directly from module.vpc.subnet_ids, without the need for a redundant extra API call to look them up:
output "vpc_private_subnets_ids" {
value = ["${module.vpc.subnet_ids}"]
}
Aside from the error about count, the configuration you showed also has a race condition because the data "aws_subnet_ids" "private_subnet_ids" block depends only on the VPC itself, and not on the individual VPCs, and so Terraform can potentially read that data source before the subnets have been created. Exporting the subnet ids through module output means that any reference to module.vpc.subnet_ids indirectly depends on all of the subnets and so those downstream actions will wait until all of the subnets have been created.
As a general rule, a particular Terraform configuration should either be managing an object or reading that object via a data source, and not both together. If you do both together then it may sometimes work but it's easy to inadvertently introduce race conditions like this, where Terraform can't tell that the data resource is attempting to consume the result of another resource block that's participating in the same plan.
here i'm trying to provision a aws classic ELB in a VPC where i have 2 public subnets. These subnets are also provisioned by terraform and i'm trying to pass both the subnets ids to elb module.SO the problem is i'm not able to give list input to elb subnets field
public_subnet variable works fine as i have used it for route table association it's just that i'm not able to handle the list and give it as input to vpc.
it works if i use subnets = [var.public_subnet.0,var.public_subnet.1]
here's my code
resource "aws_elb" "webelb" {
name = "foobar-terraform-elb"
#availability_zones = [var.public_subnet]
subnets = [var.public_subnet]
#
#
#
}
variable "public_subnet" {
type = list
}
subnet.tf
output "public_subnet" {
value = aws_subnet.public.*.id
}```
Error:
```Error: Incorrect attribute value type
on elb/elb.tf line 4, in resource "aws_elb" "webelb":
4: availability_zones = [var.public_subnet]
Inappropriate value for attribute "availability_zones": element 0: string
required.```
Since var.public_subnet is already a list. [var.public_subnet] is equivalent to [["192.168.0.0/32"]] instead of the expected, un-nested input ["102.168.0.0/32"]
ie...just use var.public_subnet
I am looking to create approx. 15 virtual machines with Terraform, of which all have their own Size in Azure such as B2S, B2MS etc. They also have different sized disks. I understand that you can use Copy Index to loop through arrays, however I'm not sure of the best way to do this with VM's that have lots of properties that are different.
Is there a way to create a map object for each VM specification and then just loop through it with a Virtual Machine creation in the TF file? At the moment the only way I can see of doing it is creating a separate virtual machine resource in the main file and referencing each individual map file..
Create a map as you mention with the vm prefix as the key and size as the value:
variable "vms" {
type = "map"
default = {
vm1 = "Standard_DS1_v2"
vm2 = "Standard_ES2_v2"
}
}
Create your VMS:
# Network Interfaces for each one of the VMs
resource "azurerm_network_interface" "main" {
# looping to create a resource for each entry in the map
for_each = var.vms
# Accessing keys in the map by each.key
name = "${each.key}-nic"
...
}
resource "azurerm_virtual_machine" "main" {
# Looping to create a VM per entry in the map
for_each = var.vms
# Accessing names of map entries
name = "vm-${each.key}-we"
# Here we make sure we access the corrrect
network_interface_ids = [azurerm_network_interface.main[each.key]]
vm_size = each.value
...
os_profile {
# Accessing names of map entries again
computer_name = "vm-${each.key}-we"
...
}
...
}
For brevity I didn't write down the whole example of creating azure vms.
There's many attributes you'll have to fill in as you need them.
Docs about how to create Azure VMS: https://www.terraform.io/docs/providers/azurerm/r/virtual_machine.html
Docs about resources and "looping" them: https://www.terraform.io/docs/configuration/resources.html
Terraform has seriously the best docs out there IMO.
I have written a Terraform script to create a few Azure Virtual Machines.
The number of VMs created is based upon a variable called type in my .tfvars file:
type = [ "Master-1", "Master-2", "Master-3", "Slave-1", "Slave-2", "Slave-3" ]
My variables.tf file contains the following local:
count_of_types = "${length(var.type)}"
And my resources.tf file contains the code required to actual create the relevant number of VMs from this information:
resource "azurerm_virtual_machine" "vm" {
count = "${local.count_of_types}"
name = "${replace(local.prefix_specific,"##TYPE##",var.type[count.index])}-VM"
location = "${azurerm_resource_group.main.location}"
resource_group_name = "${azurerm_resource_group.main.name}"
network_interface_ids = ["${azurerm_network_interface.main.*.id[count.index]}"]
vm_size = "Standard_B2ms"
tags = "${local.tags}"
Finally, in my output.tf file, I output the IP address of each server:
output "public_ip_address" {
value = ["${azurerm_public_ip.main.*.ip_address}"]
}
I am creating a Kubernetes cluster with 1x Master and 1x Slave VM. For this purpose, the script works fine - the first IP output is the Master and the second IP output is the Slave.
However, when I move to 8+ VMs in total, I'd like to know which IP refers to which VM.
Is there a way of amending my output to include the type local, or just the server's hostname alongside the Public IP?
E.g. 54.10.31.100 // Master-1.
Take a look at formatlist (which is one of the functions for string manipulations) and can be used to iterate over the instance attributes and list tags and other attributes of interest.
output "ip-address-hostname" {
value = "${
formatlist(
"%s:%s",
azurerm_public_ip.resource_name.*.fqdn,
azurerm_public_ip.resource_name.*.ip_address
)
}"
}
Note this is just a draft pseudo code. You may have to tweak this and create additional data sources in your TF file for effective enums
More reading available - https://www.terraform.io/docs/configuration/functions/formatlist.html
Raunak Jhawar's answer pointed me in the right direction, and therefore got the green tick.
For reference, here's the exact code I used in the end:
output "public_ip_address" {
value = "${formatlist("%s: %s", azurerm_virtual_machine.vm.*.name, azurerm_public_ip.main.*.ip_address)}"
}
This resulted in the following output:
I am not able to target a single aws_volume_attachment with its corresponding aws_instance via -target.
The problem is that the aws_instance is taken from a list by using count.index, which forces terraform to refresh all aws_instance resources from that list.
In my concrete case I am trying to manage a consul cluster with terraform.
The goal is to be able to reinit a single aws_instance resource via the -target flag, so I can upgrade/change the whole cluster node by node without downtime.
I have the following tf code:
### IP suffixes
variable "subnet_cidr" { "10.10.0.0/16" }
// I want nodes with addresses 10.10.1.100, 10.10.1.101, 10.10.1.102
variable "consul_private_ips_suffix" {
default = {
"0" = "100"
"1" = "101"
"2" = "102"
}
}
###########
# EBS
#
// Get existing data EBS via Name Tag
data "aws_ebs_volume" "consul-data" {
count = "${length(keys(var.consul_private_ips_suffix))}"
filter {
name = "volume-type"
values = ["gp2"]
}
filter {
name = "tag:Name"
values = ["${var.platform_type}.${var.platform_id}.consul.data.${count.index}"]
}
}
#########
# EC2
#
resource "aws_instance" "consul" {
count = "${length(keys(var.consul_private_ips_suffix))}"
...
private_ip = "${cidrhost(aws_subnet.private-b.cidr_block, lookup(var.consul_private_ips_suffix, count.index))}"
}
resource "aws_volume_attachment" "consul-data" {
count = "${length(keys(var.consul_private_ips_suffix))}"
device_name = "/dev/sdh"
volume_id = "${element(data.aws_ebs_volume.consul-data.*.id, count.index)}"
instance_id = "${element(aws_instance.consul.*.id, count.index)}"
}
This works perfectly fine for initializing the cluster.
Now I make a change in my user_data init script of the consul nodes and want to rollout node by node.
I run terraform plan -target=aws_volume_attachment.consul_data[0] to reinit node 0.
This is when I run into the above mentioned problem, that terraform renders all aws_instance resources because of instance_id = "${element(aws_instance.consul.*.id, count.index)}".
Is there a way to "force" tf to target a single aws_volume_attachment with only its corresponding aws_instance resource?
At the time of writing this sort of usage is not possible due to the fact that, as you've seen, an expression like aws_instance.consul.*.id creates a dependency on all the instances, before the element function is applied.
The -target option is not intended for routine use and is instead provided only for exceptional circumstances such as recovering carefully from an unintended change.
For this specific situation it may work better to use the ignore_changes lifecycle setting to prevent automatic replacement of the instances when user_data changes, like this:
resource "aws_instance" "consul" {
count = "${length(keys(var.consul_private_ips_suffix))}"
...
private_ip = "${cidrhost(aws_subnet.private-b.cidr_block, lookup(var.consul_private_ips_suffix, count.index))}"
lifecycle {
ignore_changes = ["user_data"]
}
}
With this set, Terraform will detect but ignore changes to the user_data attribute. You can then get the gradual replacement behavior you want by manually tainting the resources one at a time:
$ terraform taint aws_instance.consul[0]
On the next plan, Terraform will then see that this resource instance is tainted and produce a plan to replace it. This gives you direct control over when the resources are replaced, so you can therefore ensure that e.g. the consul leave step gets a chance to run first, or whatever other cleanup you need to do.
This workflow is recommended over -target because it makes the replacement step explicit. -target can be confusing in a collaborative environment because there is no evidence of its use, and thus no clear explanation of how the current state was reached. taint, on the other hand, explicitly marks your intention in the state where other team members can see it, and then replaces the resource via the normal plan/apply steps.