dhall-terraform

dhall-terraform uses terraform's provider schema to generate Dhall types & defaults for each resource, data_source & provider block.

This allows us to use Dhall to create cloud resources instead of HCL & avoid its limitations.

Installation

You can use one of cabal-install, stack or nix to build and install the project.

Usage

• Use dhall-terraform to generate the types of your provider. See here how you can generate the provider's schema.
• Write the resources in Dhall. Checkout the examples.
• Use dhall-to-json to generate terraform's JSON syntax
• Continue with terraform operations as normal.

AWS example

Example using the generated resources from the AWS provider.

let Prelude =
      https://raw.githubusercontent.com/dhall-lang/dhall-lang/master/Prelude/package.dhall

-- Get the correct type needed for Terraform's JSON syntax.
let jsonRes = λ(a : Type) → { mapKey : Text, mapValue : a }

-- Create a JSON serialized resource given its name and type.
let mkRes =
        λ(a : Type)
      → λ(name : Text)
      → λ(body : a)
      → Prelude.JSON.keyValue a name body

-- Import the necessary resources.
let AwsProvider =
      https://raw.githubusercontent.com/mujx/dhall-terraform/99a96658642aef74f0b01c0da73f2c9a07171f52/lib/aws/provider/provider.dhall

let AwsS3Bucket =
      https://raw.githubusercontent.com/mujx/dhall-terraform/99a96658642aef74f0b01c0da73f2c9a07171f52/lib/aws/resources/aws_s3_bucket.dhall

let defaultRegion = "us-east-1"

let Bucket = { region : Text, name : Text }

let buckets =
        [ { region = defaultRegion, name = "images" }
        , { region = defaultRegion, name = "files" }
        ]
      : List Bucket

let toBucketResource
    : Bucket → jsonRes AwsS3Bucket.Type
    =   λ(bkt : Bucket)
      → mkRes
          AwsS3Bucket.Type
          bkt.name
          AwsS3Bucket::{
          , tags = Some [ { mapKey = "content", mapValue = bkt.name } ]
          , region = Some defaultRegion
          }

let awsProvider =
      mkRes
        AwsProvider.Type
        "aws"
        AwsProvider::{ region = defaultRegion, version = Some "2.34.0" }

in  { provider = [ awsProvider ]
    , resource =
        { aws_s3_bucket =
            Prelude.List.map
              Bucket
              (jsonRes AwsS3Bucket.Type)
              toBucketResource
              buckets
        }
    }

Options

dhall-terraform :: v0.1.0

Usage: dhall-terraform (-f|--schema-file SCHEMA) (-p|--provider-name PROVIDER)
                       [-o|--output-dir OUT_DIR]
  Generate Dhall types from Terraform resources

Available options:
  -h,--help                Show this help text
  -f,--schema-file SCHEMA  Terraform provider's schema definitions
  -p,--provider-name PROVIDER
                           Which provider's resources will be generated
  -o,--output-dir OUT_DIR  The directory to store the generated
                           files (default: "./lib")