HXL

An Elixir implementation of HCL

Features

• Decode from string or file
• Aims to be fully compliant with the HCL specification
• Function & variables support during evaluation

Example Usage

hcl = """
resource "upcloud_server" "server1" {
  hostname = "terraform.example.com"

  zone = "nl-ams1"

  plan = "1xCPU-1GB"

  template {
    size = 25
    storage = "01000000-0000-4000-8000-000030200200"
  }

  network_interface {
    type = "public"
  }

  login {
    user = "root"
    keys = [
      "ssh-rsa public key",
    ]
    create_password = true
    password_delivery = "email"
  }

  connection {
    host        = "127.0.0.2"
    type        = "ssh"
    user        = "root"
    private_key = file("~/.ssh/rsa_private_key")
  }

  provisioner "remote-exec" {
    inline = [
      "echo 'Hello world!'"
    ]
  }
}
"""

{:ok, config_file} = HXL.decode(hcl, functions: %{"file" => &File.read/1})

From file

{:ok, config_file} = HXL.decode_file("/path/to/file")

As ast

hcl = """
service "http" {
  a = 1
  b = 2
}
"""

{:ok, %HXL.Body{}} = HXL.decode_as_ast(hcl)

Installation

Add hxl to your list of dependencies in mix.exs:

def deps do
  [
    {:hxl, "~> 0.1.0"}
  ]
end

HCL Syntax Specification

Lexical Elements

• [x] Comments
• [x] Identifiers
• [x] Operators & delimiters
• [x] Numeric literals

Structural Language

• [x] Body
• [x] Attributes
• [x] Blocks
• [x] One-line blocks

Expression language

• [x] Expressions
  • [x] Expr term
  • [x] Literal Value
  • [x] Collection Value
  • [x] Template Expr
  • [x] Variable Expr
  • [x] Function Call
  • [x] For Expr
  • [x] ExprTerm Index
  • [x] ExprTerm GetAttr
  • [x] ExprTerm Splat
  • [x] "(" Expression ")"
  • [x] Operation
  • [x] Conditional

Template Language

• [] TemplateLiteral
• [] TemplateInterpolation
• [] TemplateDirective

Representations

• [x] HCL Native syntax
• [ ] JSON