Introducte Terraform config DSL

lib/command/generate.rb

@@ -9,7 +9,7 @@ def copy_files
     end
 
     def self.source_root
-      File.expand_path("../", __dir__)
+      Cpflow.root_path.join("lib")
     end
   end
 

lib/command/terraform/generate.rb

@@ -13,7 +13,19 @@ class Generate < Base
       VALIDATIONS = [].freeze
 
       def call
-        # TODO: Implement
+        File.write(terraform_dir.join("providers.tf"), cpln_provider.to_tf)
+      end
+
+      private
+
+      def cpln_provider
+        ::Terraform::Config::RequiredProvider.new("cpln", source: "controlplane-com/cpln", version: "~> 1.0")
+      end
+
+      def terraform_dir
+        @terraform_dir ||= Cpflow.root_path.join("terraform").tap do |path|
+          FileUtils.mkdir_p(path)
+        end
       end
     end
   end

lib/core/terraform/config/base.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+require_relative "dsl"
+
+module Terraform
+  module Config
+    class Base
+      include Dsl
+
+      def to_tf
+        raise NotImplementedError
+      end
+    end
+  end
+end

lib/core/terraform/config/dsl.rb

@@ -0,0 +1,84 @@
+# frozen_string_literal: true
+
+module Terraform
+  module Config
+    module Dsl
+      extend Forwardable
+
+      def_delegators :current_context, :put, :output
+
+      def block(name, *labels)
+        switch_context do
+          put("#{block_declaration(name, labels)} {\n")
+          yield
+          put("}\n")
+        end
+
+        # There is extra indent for whole output that needs to be removed
+        output.unindent(2)
+      end
+
+      def argument(name, value, optional: false)
+        return if value.nil? && optional
+
+        content =
+          if value.is_a?(Hash)
+            "{\n#{value.map { |n, v| "#{n} = #{tf_value(v)}" }.join("\n").indent(2)}\n}\n"
+          else
+            "#{tf_value(value)}\n"
+          end
+
+        put("#{name} = #{content}", indent: 2)
+      end
+
+      private
+
+      def tf_value(value)
+        value = value.to_s if value.is_a?(Symbol)
+
+        case value
+        when String
+          expression?(value) ? value : "\"#{value}\""
+        else
+          value
+        end
+      end
+
+      def expression?(value)
+        value.start_with?("var.") || value.start_with?("locals.")
+      end
+
+      def block_declaration(name, labels)
+        result = name
+        return result unless labels.any?
+
+        result + " #{labels.map { |label| tf_value(label) }.join(' ')}"
+      end
+
+      class Context
+        attr_accessor :output
+
+        def initialize
+          @output = ""
+        end
+
+        def put(content, indent: 0)
+          @output += content.indent(indent)
+        end
+      end
+
+      def switch_context
+        old_context = current_context
+        @current_context = Context.new
+        yield
+      ensure
+        old_context.put(current_context.output, indent: 2)
+        @current_context = old_context
+      end
+
+      def current_context
+        @current_context ||= Context.new
+      end
+    end
+  end
+end

lib/core/terraform/config/required_provider.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Terraform
+  module Config
+    class RequiredProvider < Base
+      attr_reader :name, :options
+
+      def initialize(name, **options)
+        super()
+
+        @name = name
+        @options = options
+      end
+
+      def to_tf
+        block :terraform do
+          block :required_providers do
+            argument name, options
+          end
+        end
+      end
+    end
+  end
+end

lib/cpflow.rb

@@ -17,6 +17,8 @@
 
 # We need to require base before all commands, since the commands inherit from it
 require_relative "command/base"
+# We need to require base terraform config before all commands, since the terraform configs inherit from it
+require_relative "core/terraform/config/base"
 
 modules = Dir["#{__dir__}/**/*.rb"].reject do |file|
   file == __FILE__ || file.end_with?("base.rb")
@@ -51,9 +53,15 @@ def print_wrapped(message, options = {})
   end
 end
 
+require_relative "patches/string"
+
 module Cpflow
   class Error < StandardError; end
 
+  def self.root_path
+    Pathname.new(File.expand_path("../", __dir__))
+  end
+
   class Cli < Thor # rubocop:disable Metrics/ClassLength
     package_name "cpflow"
     default_task :no_command
@@ -172,7 +180,8 @@ def self.process_option_params(params)
 
     def self.klass_for(subcommand_name)
       klass_name = subcommand_name.to_s.split("-").map(&:capitalize).join
-      return Cpflow.const_get(klass_name) if Cpflow.const_defined?(klass_name)
+      full_klass_name = "Cpflow::#{klass_name}"
+      return const_get(full_classname) if const_defined?(full_klass_name)
 
       Cpflow.const_set(klass_name, Class.new(BaseSubCommand)).tap do |subcommand_klass|
         desc(subcommand_name, "#{subcommand_name.capitalize} commands")

lib/patches/string.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+# rubocop:disable Style/OptionalBooleanParameter, Lint/UnderscorePrefixedVariableName
+class String
+  # Copied from Rails
+  def indent(amount, indent_string = nil, indent_empty_lines = false)
+    dup.tap { |_| _.indent!(amount, indent_string, indent_empty_lines) }
+  end
+
+  # Copied from Rails
+  def indent!(amount, indent_string = nil, indent_empty_lines = false)
+    indent_string = indent_string || self[/^[ \t]/] || " "
+    re = indent_empty_lines ? /^/ : /^(?!$)/
+    gsub!(re, indent_string * amount)
+  end
+
+  def unindent(amount, indent_string = " ")
+    lines.map { |line| line.delete_prefix(indent_string * amount) }.join
+  end
+end
+# rubocop:enable Style/OptionalBooleanParameter, Lint/UnderscorePrefixedVariableName

spec/command/generate_spec.rb

@@ -7,7 +7,6 @@
 GEM_TEMP_PATH = GEM_ROOT_PATH.join("tmp")
 GENERATOR_PLAYGROUND_PATH = GEM_TEMP_PATH.join("sample-project")
 CONTROLPLANE_CONFIG_DIR_PATH = GENERATOR_PLAYGROUND_PATH.join(".controlplane")
-CPFLOW_EXECUTABLE_PATH = GEM_ROOT_PATH.join("bin", "cpflow")
 
 def inside_dir(path)
   original_working_dir = Dir.pwd

spec/command/terraform/generate_spec.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "pathname"
+
+GEM_ROOT_PATH = Pathname.new(Dir.pwd)
+GEM_TEMP_PATH = GEM_ROOT_PATH.join("tmp")
+GENERATOR_PLAYGROUND_PATH = GEM_TEMP_PATH.join("sample-project")
+TERRAFORM_CONFIG_DIR_PATH = GENERATOR_PLAYGROUND_PATH.join("terraform")
+
+describe Command::Terraform::Generate do
+  before do
+    FileUtils.rm_r(GENERATOR_PLAYGROUND_PATH) if Dir.exist?(GENERATOR_PLAYGROUND_PATH)
+    FileUtils.mkdir_p GENERATOR_PLAYGROUND_PATH
+
+    allow(Cpflow).to receive(:root_path).and_return(GENERATOR_PLAYGROUND_PATH)
+  end
+
+  after do
+    FileUtils.rm_r GENERATOR_PLAYGROUND_PATH
+  end
+
+  it "generates terraform config files" do
+    providers_config_file_path = TERRAFORM_CONFIG_DIR_PATH.join("providers.tf")
+
+    expect(providers_config_file_path).not_to exist
+    run_cpflow_command(described_class::SUBCOMMAND_NAME, described_class::NAME)
+    expect(providers_config_file_path).to exist
+  end
+end

spec/core/terraform/config/base_spec.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+describe Terraform::Config::Base do
+  let(:config) { described_class.new }
+
+  describe "#to_tf" do
+    subject(:to_tf) { config.to_tf }
+
+    it "raises NotImplementedError" do
+      expect { to_tf }.to raise_error(NotImplementedError)
+    end
+  end
+end