My terraform project layout looks something like:
[project root dir]
main.tf
- my_module [directory]:
variables.tf
my_instance.tf
In variables.tf I have something like this:
variable "foo-ami" {
default = "ami-12345"
description = "Super awesome AMI"
}
In my_instance.tf I reference it like so:
resource "aws_instance" "my_instance" {
ami = "${var.foo-ami}"
...
}
If I want to override this variable from the command line, the docs here seem to suggest I should be able to run the following command from the top level (main.tf) location:
terraform plan -var 'foo-ami=ami-987654'
However, the variable switch doesn't seem to be getting picked up. The old value remains set. Further more if I remove the default setting I get an error from terraform saying it's not set, so clearly the -var switch isn't being picked up.
Thoughts?
TIA
The variables of root and my_module are different. If you want to pass a variable to my_module, you need to specify it.
In the main.tf, you should set the variable as follows:
variable "foo-ami" {}
module "my_module" {
source = "./my_module"
foo-ami = "${var.foo-ami}"
...
}
For details of the module feature refer to the following documents:
https://www.terraform.io/docs/modules/usage.html
Related
I have a terraform module in my local "tmp\module\vpc".
Is there any way this local path "tmp\module\vpc" can be set in a environment variable and use it in the "source" field of calling module.
module "vpc" {
source = "/tmp/modules/vpc"
vpcname = var.vpcname
}
Not possible. Dynamic module paths is not something terraform supports.
Terraform newbie would appreciate a push in the right direction.
Have created my first module, a child module to root called 'storage' in there I want to put all the templates for the storage accounts. I thought this would be simple.
I've added a folder named 'storage' and moved the existing 'storage.tf' file into that and added added modules block to my main.tf (in root) to tell it the module exists. I did a terraform init and it found and installed it - great!
But now when I try something like:
terraform plan -var-file='env/dev/dev.tfvars'
None of the variables which my storage.tf file references are found. I just get:
Error: Reference to undeclared input variable
│
│ on modules\storage\storage.tf line 11, in resource "google_storage_bucket" "new_bucket":
│ 11: name = "${var.env_name}-${var.name_of_bucket}-test"
│
│ An input variable with the name "env_name" has not been declared. This variable can be declared with a variable "env_name" {} block.
All my variables are defined in a variables.tf in root and when running terraform I pass in the path to the relevant variable values using the .tfvars method.
Why can't the module see those?
I tried creating a vars.tf in the module directory, next to the storage.tf file. I copied the variable definitions into that file and got errors that the value of the variable was missing (even though the values were in the .tfvars file used in the invocation).
I then tried adding the value to the variable definitions using the 'default' and this actually worked - but that means I can no longer use the .tfvars to control which environment I'm configuring.
I must be missing something really basic!
Question: How can I get my modules to accept the values contained in my .tfvars? I don't mind having the variables which each module needs in a seperate vars.tf for each module - thats fine and actually useful, but there has to be some way to pass in the values with a simple .tfvars? Please... what am I missing?
Update
Below is the folder and file structure, sorry if I am not using the right syntax for the graph!
condo (folder)
|--.git (folder)
|--.github (folder)
|--creds (folder)
| |--dev_creds.json (file)
| |--prod_creds.json (file)
|
|--infracomm (folder) (root)
|
|--.terraform (file)
|--.terraform.hcl.lock (file)
|--env (folder)
| |--dev (folder)
| | |--dev.tfvar (file)
| |
| |--prod (folder)
| |--prod.tfvars (file)
|
|--modules (folder) (child module)
| |--storage (folder)
| |--storage.tf (file)
|
|--backend.tf (file)
|--main.tf (file)
|--variables.tf (file)
All I am trying to do is get the variables in the root variables.tf AND the values for those variables, which I am providing in the cli arg
-var-file='./env/dev/dev.tfvars'
To be usable inside the storage module.
UPDATE #2
Here is the code from main.tf in root where I am referencing the child module. Let me know if more needed:
provider "google" {
project = var.project_name
region = "europe-west4"
zone = "europe-west4"
credentials = var.credentials_path
}
// Define modules
module "storage" {
source = "./modules/storage"
}
Do I need to duplicate those variables in a vars.tf in the module? If so, how do I get values into them without using 'default' as that would break scalability.
I'm sure I'm missing something basic.
Thanks!
Let's say you want to pass the variable variable_to_child_module in your module, from the root module.
The value of this variable was added through a .tfvars file in the root module, namely variable_from_root_module
When you call the storage module from the root module pass the variable
// Define modules
module "storage" {
source = "./modules/storage"
variable_to_child_module = var.variable_from_root_module
}
Also in ./modules/storage directory you should add a variables.tf where you will add the variable definition
E.g.
variable "variable_to_child_module" {
description = "my child module variable"
type = string
}
Consider each module (root and storage) an independent module. You need to (re)define the variables which you use in the sub-module (storage) in the sub-module itself.
Assuming you have variables region and size which you pass into the main module and want to use in storage module, you can do this as follows:
module "storage" {
source = "./modules/storage"
region = var.region
size = var.size
}
I have a configuration which uses modules, this is its structure:
main.tf
\modules
\kubernetes_cluster
\main.tf
\variables.tf
At this stage I had no separate tfvars file, I relied on default values declared in the variables.tf file, and this worked fine. I then decided to create a tfvars file resulting in:
main.tf
\modules
\kubernetes_cluster
\main.tf
\variables.tf
\variables.tfvars
At the same time I removed the default values from variables file, then when I ran:
terraform apply -target=module.kubernetes_cluster -auto-approve
I got errors complaining that I needed to pass my variables in as arguments due to the fact "They were missing", so I moved to this:
main.tf
variables.tf
variables.tfvars
\modules
\kubernetes_cluster
\main.tf
\variables.tf
this is what main.tf in the root module looks like:
module "kubernetes_cluster" {
source = "./modules/kubernetes_cluster"
kubernetes_version = var.kubernetes_version
node_hosts = var.node_hosts
}
When I run terraform apply I get prompted for the values of the variables. All I want to do is not rely on variable default values and to be able to run terraform apply from the root module directory without having to pass in variable values by hand, I suspect that my module structure somewhere along the line is not correct.
If you want to have TF load tfvars automatically, the file must be called terraform.tfvars, not variables.tfvars. There are other possibilities:
Terraform also automatically loads a number of variable definitions files if they are present:
Files named exactly terraform.tfvars or terraform.tfvars.json.
Any files with names ending in .auto.tfvars or .auto.tfvars.json.
As per the documentation, terraform automatically loads tfvars if:
Either variable file name is terraform.var or terraform.var.json
Or YOUR_NAME.auto.tfvar
So in your case renaming variables.tfvars to variables.auto.tfvars would work
I am trying to build Terragrunt script for deploying the infrastructure to Microsoft Azure cloud. Things are working fairly well but I am not able to figure out one thing.
The structure of setup looks something like this:
rootdir
terragrunt.hcl
someconfig.hcl
module1dir
terragrunt.hcl
config.auto.tfvars.json
module2dir
terragrunt.hcl
config.auto.tfvars.json
module3dir
terragrunt.hcl
config.auto.tfvars.json
Each module is configured using Terraform autoload tfvars feature with config.auto.tfvars.json. What I would like is to have these files outside of the directory structure and somehow instruct Terragrunt to apply correct external configuration file to correct submodule.
Any ideas?
I solved this in the following manner:
Define environment variable you plan on using which should contain location to the configuration files. Make sure it is not clashing with anything existing. In this example we will use TGR_CFGDIR. In the external configuration module place the module configuration files and make sure they are properly named. Each file should be named as the module and end with .auto.tfvars.json. So if your module is named foo you should have config file foo.auto.tfvars.json. Change your terragrunt modules (terragrunt.hcl) to have these statements:
locals {
moduleconfig = get_env("TGR_CFGDIR")
modulename = basename(get_terragrunt_dir())
}
generate "configuration" {
path = "config.auto.tfvars.json"
if_exists = "overwrite"
disable_signature = true
contents = file("${local.moduleconfig}/${local.modulename}.auto.tfvars.json")
}
And finally call terragrunt cli like this:
TGR_CFGDIR="<configdir>" terragrunt "<somecommand>"
I wanted to read variables into my Terraform configuration file from an external YAML file or from a database like Hiera, how can I do that? For example:
provider "aws" {
region = hiera('virginia') # this should look up for virginia=us-east-1
}
resource "aws_instance" {
ami = hiera('production')
....
....
}
Basically its similar to how we can do a lookup for Puppet manifests/configs using hiera or a YAML file.
yamldecode function can be use to read Yaml file as input for terraform and parse it to use.
Let's say test.yml file as below
a: 1
b: 2
c: 3
Then below code can be use to read the yaml file
output "log" {
value = "${yamldecode(file("test.yml"))}"
}
In order to parse a specific value read from a yaml file
output "log" {
value = "${yamldecode(file("test.yml"))["a"]}"
}
Important: this is available in 0.12 or later version of terraform, in case of using the old version of terraform and still want to use yaml file, then use terraform-provider-yaml
You can include the yaml file as a local:
locals {
config = yamldecode(file("${path.module}/configfile.yml"))
}
Now you can call all variables from local.config, for example a variable project_name:
local.config.project_name
You have to move the variables to a terraform.tfvars or a *.auto.tfvars file.
https://www.terraform.io/language/values/variables#variable-definitions-tfvars-files
To persist variable values, create a file and assign variables within
this file. Create a file named terraform.tfvars with the following
contents:
access_key = "foo"
secret_key = "bar"
For all files which match terraform.tfvars or *.auto.tfvars present in
the current directory, Terraform automatically loads them to populate
variables. If the file is named something else, you can use the
-var-file flag directly to specify a file. These files are the same syntax as Terraform configuration files. And like Terraform
configuration files, these files can also be JSON.