You can’t use interpolation in a tfvars file. Instead you could either join it directly in your Terraform like this: terraform.tfvars hosted_zone = “example.com” domain = “my” main.tf resource “aws_route53_record” “regional” { zone_id = data.aws_route53_zone.selected.zone_id name = “${var.domain}.${var.hosted_zone}” type = “A” ttl = “300” records = [“4.4.4.4”] } Or, if you always need to compose … Read more
Warning: Interpolation-only expressions are deprecated on main.tf line 3, in provider “aws”: 3: region = “${var.region}” I also got the above warning, which is due to the changed syntax for declaring variables in terraform. See the example below -: Old syntax– region = “${var.region}” # you will get Interpolation-only warning New Synatx– region = var.region … Read more
Terraform 0.12 (yet to be released) will also bring support for HCL2 which allows you to use nullable arguments with something like this: resource “aws_ebs_volume” “my_volume” { availability_zone = “xyz” size = 30 snapshot_id = var.staging_mode ? local.a_specific_snapshot_id : null } Nullable arguments are covered in this 0.12 preview guide. For version of Terraform before … Read more
Seems these days you can also use try to check if something is set. try(var.env, false) After that your code will work since var.env is now defined with the value false even if var.env was never defined somewhere. https://www.terraform.io/docs/configuration/functions/try.html
There is no –except feature in terraform destroy command currently. If you really want to do that, and you know what you are doing, here is the workaround. # list all resources terraform state list # remove that resource you don’t want to destroy # you can add more to be excluded if required terraform … Read more
There’s (now) a lookup function supported in the terraform interpolation syntax, that allows you to lookup dynamic keys in a map. Using this, I can now do stuff like: output “image_bucket_name” { value = “${lookup(var.image_bucket_names, var.environment, “No way this should happen”)}” } where: variable “image_bucket_names” { type = “map” default = { development = “bucket-dev” … Read more
Terraform operates by calling into the APIs of various service providers and systems. Thus in principle Terraform can manage anything that has an API, and in practice it has existing support for a few different on-premises-capable systems, including: OpenStack VMWare vSphere CloudStack If the compute resources in your existing datacenter infrastructure are already managed with … Read more
The distinction between these is of declaration vs. assignment. variable blocks (which can actually appear in any .tf file, but are in variables.tf by convention) declare that a variable exists: variable “example” {} This tells Terraform that this module accepts an input variable called example. Stating this makes it valid to use var.example elsewhere in … Read more
Terraform does not support variables inside a variable. If you want to generate a value based on two or more variables then you can try Terraform locals. You can define the locals like this: locals { tags = { Environment = “${var.EnvironmentName}” CostCentre = “C1234” Project = “TerraformTest” Department = “Systems” } } And then … Read more