Terraform <> Heroku

Terraform
1

Hi I am trying to use terraform with heroku and use the postgres backend option.

I am trying to segment the code into different folders for different environments but the state file in postgres seems to store everything in one… when I switch from folder a to folder b and tun terraform plan , it tries to delete resources from folder a and create resources from folder b.

Is there any guides on separating the backend config so each folder has its own state file ?

2

You have already had to configure storing the state in Postgres - so just configure different state locations for different environments.

3

my question was how ? the provider.tf config section doesnt allow for functions

│ on provider.tf line 12, in terraform:
│ 12: key = “${path_relative_to_include()}”
│
│ Functions may not be called here.

… do I have to manually edit each provider file with a unique path in each folder?

4

I recommend you post your complete Terraform code in a GitHub repo and link it here. It’s not really possible to help you with the very limited amount of information you’re currently sharing.

5

here is the github link. You will see 2 seperate folders for creating 2 different environment however with using backend pg {} somehow the state file for both points to the same location so if I switch folders and run terraform plan , it tries to delete whatever resource that is not in the current folder.

When I used to play with terraform and GCP we would differentiate folders and state file using :

remote_state {
backend = “gcs”

config = {
  bucket  = "${get_env("ENV", "default")}-tf-states"
  prefix  = "${path_relative_to_include()}"
  project = "${get_env("GOOGLE_PROJECT", "terraform")}"
}

}

this created a unique statefile for every folder.

6

I think you’re using some third-party wrapper for Terraform and not including relevant information about it in your posts, so I am unable to help you.

7

not sure what other info you need besides the repo link ? it has two heroku app folders each with similar setup just name diff for app.

you can check provider.tf

terraform {
required_version = “>= 1.0”

required_providers {
heroku = {
source = “heroku/heroku”
version = “~> 5.0”
}
}
backend “pg” {
}
}

I have another heroku app that has the postgres instance where I would like to store the statefiles :

export DATABASE_URL=heroku config:get DATABASE_URL --app ex-terraform

terraform init -backend-config=“conn_str=$DATABASE_URL”

The reference to google setup was something I have done in the past but the heroku setup is as basic as it gets.

8

and here is the issue I am talking about :

Plan: 44 to add, 0 to change, 44 to destroy.

44 resources were created in folder staging-7 , when I navigate to folder staging-8 and run terraform plan it tries to destroy 44 resources from staging-7 and create 44 for staging-8 ( likely because they are pointing to same statefile)

what I am trying to solve for : Each folder gets its unique statefile

9

Some code snippets you have shared imply you may be using Terragrunt. However, you’ve left all Terragrunt configuration out of the Git repository I suggested you share.

I therefore feel I don’t understand enough about your setup to give good advice.

10

I am not using terragrunt in the current setup. Terragrunt was something I used in the previous setup with google cloud and I was trying to mimic the same behavior with heroku <> terraform.

However, my terraform setup for heroku is all in that repo I shared. No use of terragrunt since that would complicate the setup. I just wanted to use terraform out of the box and use their recommendation on using postgres instance to store states.

Is there a way to have a state file for each folder in a vanilla terraform setup ? I want to create several apps and have them each be independent from a statefile perspective.

11

Thank you for removing the ambiguity of whether Terragrunt was involved.

In that case, I think the most promising option might be for you to explicitly configure a different schema_name in your backend "pg" {} block in each directory. See https://developer.hashicorp.com/terraform/language/settings/backends/pg#schema_name

12

here is what I tried to do right now :

`terraform {
  required_version = ">= 1.0"
  backend "pg" {}
  required_providers {
    heroku = {
      source  = "heroku/heroku"
      version = "~> 5.0"
    }
  }
}

data "terraform_remote_state" "staging_7" {
  backend = "pg"

  config = {
    prefix = "envs/staging/staging7"
   }
  
}

and terraform init complains :

   with data.terraform_remote_state.reforge_staging_7,
│   on provider.tf line 15, in data "terraform_remote_state" "reforge_staging_7":
│   15:   config = {
│   16:     prefix = "envs/staging/staging7"
│   17:    }
│ 
│ The given configuration is not valid for backend "pg": unexpected attribute "prefix".