I'm learning terraform by building a template to create my infrastructure in the hetzner cloud. For this purpose I'm using the hcloud provider.
I create a map variable hosts to create >1 server with different configuration.
variable "hosts" {
type = map(object({
name = string
serverType = string
serverImage = string
serverLocation = string
serverKeepDisk = bool
serverBackup = bool
ip = string
}))
}
This is working fine. But I need to configure also volumes. I need only for 2 servers additional volumes and terraform has to check if variable volume is true or not. If true a new volume with given details should be created and attached to the server.
For this I edit my variable hosts:
variable "hosts" {
type = map(object({
name = string
serverType = string
serverImage = string
serverLocation = string
serverKeepDisk = bool
serverBackup = bool
ip = string
volume = bool
volumeName = string
volumeSize = number
volumeFormat = string
volumeAutomount = bool
volumeDeleteProtection = bool
}))
}
in the main.tf the volume block looks like this, but it doesnt work because for_each and count cant be used together. How can I get what I'm looking for? Is that possible?
resource "hcloud_volume" "default" {
for_each = var.hosts
count = each.value.volume ? 1 : 0
name = each.value.volumeName
size = each.value.volumeSize
server_id = hcloud_server.default[each.key].id
automount = each.value.volumeAutomount
format = each.value.volumeFormat
delete_protection = each.value.volumeDeleteProtection
}
The former iterative meta-argument count will not provide you with the functionality you need here, as you need to access the volume bool type on a per var.hosts iteration in the map. To that end, you can add a conditional in a for expression within the for_each meta-argument.
for_each = { for host, values in var.hosts: host => values if values.volume }
This will construct a map for the value of the for_each meta-argument. It will contain every key value pair of var.hosts for which the volume object key is true.
It would seem like this would be a good fit for a collect or map method or function which transforms list and map types and exist in many other languages, but these do not yet exist in Terraform. Therefore, we use a for expression lambda equivalent.
Related
I am trying to build a virtual network using a terraform script. I am struggling with creating a loop on the variable "vcn" below. My use case is as follows
A "vcn" object can have 1 to many "ads" objects
Each "ads" object has 1 to many "subnets" object
I represented the object as shown below ( assuming that is the correct representation )
How do I create a for-each loop in a terraform script?
variable "vcn" {
type = map(object({
vcn_cidr_block_in = string
ads = map(object({
subnets = map(object({
sub_cidr_block_in = string
sub_display_name_in = string
sub_dns_label_in = string
}))
ad_name = string
}))
}))
}
Appreciate any guidance to solve this problem.
TIA
I'm currently using the terraform-aws-eks module and wanted to setup a managed node group in an existing cluster. However, I only want this node group to appear in our dev environment (but still want the cluster to remain unchanged). Is there a way to skip a variable assignment conditionally for a module? I tried the below approach but get an error if var.deploy_managed_node_group = false. Terraform version 0.14.11.
module "eks" {
source = "./modules/eks-17.24.0"
cluster_enabled_log_types = var.cluster_enabled_log_types
cluster_name = local.eks_cluster_name
cluster_version = local.eks_version
iam_path = "/eks/"
manage_aws_auth = true
map_users = local.eks_users
map_roles = local.eks_roles
subnets = module.eks_vpc.private_subnets
vpc_id = module.eks_vpc.vpc_id
worker_groups = local.worker_groups
node_groups = var.deploy_managed_node_group ? local.node_groups : null
}
Error: Iteration over null value
node_groups variable from module:
variable "node_groups" {
description = "Map of map of node groups to create. See `node_groups` module's documentation for more details"
type = any
default = {}
}
When using types in Terraform such as set, list, or map, the omitted value should be "empty" instead of null if the value is utilized for iteration instead of an argument. Therefore:
node_groups = var.deploy_managed_node_group ? local.node_groups : {}
would be the ideal ternary here as the falsey value returned by the conditional is an empty map constructor.
I have multiple aws_glue_catalog_table resources and I want to create a single output that loops over all resources to show the S3 bucket location of each one. The purpose of this is to test if I am using the correct location (because it is a concatenation of variables) for each resource in Terratest. I cannot use aws_glue_catalog_table.* or aws_glue_catalog_table.[] because Terraform does not allow to reference a resource without specifying its name.
So I created a variable "table_names" with r1, r2, rx. Then, I can loop over the names. I want to create the string aws_glue_catalog_table.r1.storage_descriptor[0].location dynamically, so I can check if the location is correct.
resource "aws_glue_catalog_table" "r1" {
name = "r1"
database_name = var.db_name
storage_descriptor {
location = "s3://${var.bucket_name}/${var.environment}-config/r1"
}
...
}
resource "aws_glue_catalog_table" "rX" {
name = "rX"
database_name = var.db_name
storage_descriptor {
location = "s3://${var.bucket_name}/${var.environment}-config/rX"
}
}
variable "table_names" {
description = "The list of Athena table names"
type = list(string)
default = ["r1", "r2", "r3", "rx"]
}
output "athena_tables" {
description = "Athena tables"
value = [for n in var.table_names : n]
}
First attempt: I tried to create an output "athena_tables_location" with the syntax aws_glue_catalog_table.${table} but does does.
output "athena_tables_location" {
// HOW DO I ITERATE OVER ALL TABLES?
value = [for t in var.table_names : aws_glue_catalog_table.${t}.storage_descriptor[0].location"]
}
Second attempt: I tried to create a variable "table_name_locations" but IntelliJ already shows an error ${t} in the for loop [for t in var.table_names : "aws_glue_catalog_table.${t}.storage_descriptor[0].location"].
variable "table_name_locations" {
description = "The list of Athena table locations"
type = list(string)
// THIS ALSO DOES NOT WORK
default = [for t in var.table_names : "aws_glue_catalog_table.${t}.storage_descriptor[0].location"]
}
How can I list all table locations in the output and then test it with Terratest?
Once I can iterate over the tables and collect the S3 location I can do the following test using Terratest:
athenaTablesLocation := terraform.Output(t, terraformOpts, "athena_tables_location")
assert.Contains(t, athenaTablesLocation, "s3://rX/test-config/rX",)
It seems like you have an unusual mix of static and dynamic here: you've statically defined a fixed number of aws_glue_catalog_table resources but you want to use them dynamically based on the value of an input variable.
Terraform doesn't allow dynamic references to resources because its execution model requires building a dependency graph between all of the objects, and so it needs to know which exact resources are involved in a particular expression. However, you can in principle build your own single value that includes all of these objects and then dynamically choose from it:
locals {
tables = {
r1 = aws_glue_catalog_table.r1
r2 = aws_glue_catalog_table.r2
r3 = aws_glue_catalog_table.r3
# etc
}
}
output "table_locations" {
value = {
for t in var.table_names : t => local.tables[t].storage_descriptor[0].location
}
}
With this structure Terraform can see that output "table_locations" depends on local.tables and local.tables depends on all of the relevant resources, and so the evaluation order will be correct.
However, it also seems like your table definitions are systematic based on var.table_names and so could potentially benefit from being dynamic themselves. You could achieve that using the resource for_each feature to declare multiple instances of a single resource:
variable "table_names" {
description = "Athena table names to create"
type = set(string)
default = ["r1", "r2", "r3", "rx"]
}
resource "aws_glue_catalog_table" "all" {
for_each = var.table_names
name = each.key
database_name = var.db_name
storage_descriptor {
location = "s3://${var.bucket_name}/${var.environment}-config/${each.key}"
}
...
}
output "table_locations" {
value = {
for k, t in aws_glue_catalog_table.all : k => t.storage_descriptor[0].location
}
}
In this case aws_glue_catalog_table.all represents all of the tables together as a single resource with multiple instances, each one identified by the table name. for_each resources appear in expressions as maps, so this will declare resource instances with addresses like this:
aws_glue_catalog_table.all["r1"]
aws_glue_catalog_table.all["r2"]
aws_glue_catalog_table.all["r3"]
...
Because this is already a map, this time we don't need the extra step of constructing the map in a local value, and can instead just access this map directly to build the output value, which will be a map from table name to storage location:
{
r1 = "s3://BUCKETNAME/ENVNAME-config/r1"
r2 = "s3://BUCKETNAME/ENVNAME-config/r2"
r3 = "s3://BUCKETNAME/ENVNAME-config/r3"
# ...
}
In this example I've assumed that all of the tables are identical aside from their names, which I expect isn't true in practice but I was going only by what you included in the question. If the tables do need to have different settings then you can change var.table_names to instead be a variable "tables" whose type is a map of object type where the values describe the differences between the tables, but that's a different topic kinda beyond the scope of this question, so I won't get into the details of that here.
I am trying to work around a constraint where firewall creation is split into 2 sections, creating a filter and creating the rule based on the filter. Filter creation exposes a filter id that should be used in the fw rule creation. I cant wrap my head on how to properly iterate through the map that has values for filter and rule and include newly created filter. if i just use a simple map with name and expression, things work, but if i add rule priority things break
here is my map
variable "fw_allowfilters1" {
description = "list of expressions for firewall to be included in the allow rules"
type = map(object({
fvalue = string
priority = number
}))
default = {
"office_filter1" = [
{
fvalue = "ip.geoip.asnum eq 111111"
priority = 1
}
]
"office_filter2" = [
{
fvalue = "ip.src eq 8.8.8.8"
priority = 3
}
]
}
}
now here is my code for both filter and FW
resource "cloudflare_filter" "allow-filters1" {
for_each = var.fw_allowfilters1
zone_id = var.zoneid
expression = each.value.fvalue
description = each.key
//description = [for o in var.fw_allowfilters1: "Filter_${var.fw_allowfilters1.name}"]
//expression = [for o in var.fw_allowfilters1: var.fw_allowfilters1.value]
}
resource "cloudflare_firewall_rule" "whitelist-rule" {
for_each = cloudflare_filter.allow-filters1
action = "allow"
filter_id = tostring(each.value.id)
zone_id = var.zoneid
description = [for p in var.fw_allowfilters1.name: p.name ]
priority = [for p in var.fw_allowfilters1.priority: p.priority ]
}
now if i dont include priority, i can do the for_each on the filter output in firewall creation, using id output from the resource and key for descirption ( cf tf provider uses description as a name) however, if i need to add the key, i need to iterate through the map with values plus the id that is output of the filter creation and I am not sure how to properly map it. code currently does not work.
so i figured it out and it was not easy:) using locals helped me create proper iterators:
resource "cloudflare_filter" "filters1" {
for_each = var.fw_rules
zone_id = var.zoneid
description = "Filter_${tostring(each.key)}"
expression = tostring(each.value[0])
}
locals {
filterids = [for f in cloudflare_filter.filters1 : f.id] //putting filter
IDs into a separate list for concat later
fwvalues = (values(var.fw_rules)) // putting values from the map of fwvalues into
a separate list to use the index position of a particular value as an interator when
creating commong object that has both filterid and fwvalues
fwkeys = (keys(var.fw_rules)) //putting keys into a separate list
//iterating over all elements in the allowfilters1, combining existing lists in the
variable with the ID value and readding the key as an element in the list
withid3 = {for p in var.fw_rules : local.fwkeys[index(local.fwvalues, p.*)] =>
concat(p, list(local.filterids[index(local.fwvalues,
p.*)]),list(local.fwkeys[index(local.fwvalues, p.*)]))} //working version
}
resource "cloudflare_firewall_rule" "fw-rules" {
for_each = local.withid3
action = each.value[2]
filter_id = each.value[4]
paused = each.value[3]
zone_id = var.zoneid
description = "FW-${tostring(each.value[2])}-${tostring(each.key)}"
priority = each.value[1]
}
where varilable is this:
// the syntax is the following: name of the rule(try to be precise = [ expression, priority,action, disabled - boolean] - all values should be strings, make sure to terminate the quotes correctly
allowed values for the action are: block, challenge, js_challenge, allow, log, bypass
list has to be maintained according to the rule priority
variable "fw_rules" {
description = "list of expressions for firewall to be included in therules"
type = map
default = {
office_allow = ["putexpressionhere","1","allow","false"],
office_allow1 = ["putexpressionhere1","2","deny","false"]
}
I currently have this map in a test.tfvars file:
ssm = {
names = ["Terraform-1","Terraform-2","Terraform-3"]
values = ["tf-1","tf-2","tf-3"]
}
And what I want to do is the following:
resource "aws_ssm_parameter" "parameter_store" {
count = 3
name = "$${element(var.ssm[names],count.index)}"
type = "String"
value = "$${element(var.ssm[values],count.index)}"
}
But instead of count=3, I would like the count to be based off of the length of the names list from my ssm map. I've tried this:
"${length(var.ssm[names])}"
But I'm getting the error:
Error: aws_ssm_parameter.parameter_store: resource count can't reference variable: names
Can anyone point me in the right direction with solving this error? I'm not too sure what I'm doing wrong.
The current terraform version (0.11.x) behaves sometimes a bit strange, when it needs to handle lists nested in a map. This might be fixed with the new version 0.12.x, but maybe there is a better solution for that...
Why do you not restructure your map like this:
ssm = {
"Terraform-1" = "tf-1"
"Terraform-2" = "tf-2"
"Terraform-3" = "tf-3"
}
Your resource would now look like this:
resource "aws_ssm_parameter" "parameter_store" {
count = "${length(var.ssm)}"
name = "${keys(var.ssm)[count.index]}"
type = "String"
value = "${values(var.ssm)[count.index]}"
}