Move the terraform utilities to lib/

Change the module to a class, which is used to represent a terraform
working directory.

Change the routing for the terraform http backends, to remove any
connection with mini environments, and remove this concern from the
new TerraformWorkingDirectory class also.

3 files changed, 18 insertions, 72 deletions

diff --git a/app/models/backends/terraform.rb b/app/models/backends/terraform.rb
deleted file mode 100644
index b3c6ee7..0000000
--- a/app/models/backends/terraform.rb
+++ /dev/null
@@ -1,64 +0,0 @@
-# GOV.UK Mini Environment Admin
-# Copyright © 2018  Christopher Baines <mail@cbaines.net>
-#
-# This file is part of the GOV.UK Mini Environment Admin.
-#
-# The GOV.UK Mini Environment Admin is free software: you can
-# redistribute it and/or modify it under the terms of the GNU Affero
-# General Public License as published by the Free Software Foundation,
-# either version 3 of the License, or (at your option) any later
-# version.
-#
-# The GOV.UK Mini Environment Admin is distributed in the hope that it
-# will be useful, but WITHOUT ANY WARRANTY; without even the implied
-# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-# See the GNU Affero General Public License for more details.
-#
-# You should have received a copy of the GNU Affero General Public
-# License along with the GOV.UK Mini Environment Admin.  If not, see
-# <http://www.gnu.org/licenses/>.
-
-require 'fileutils'
-
-module Backends::Terraform
-  def working_directory(mini_environment)
-    "tmp/terraform-working-directories/#{mini_environment.name}"
-  end
-
-  def with_terraform(mini_environment, source)
-    source = File.expand_path(source)
-    FileUtils.mkdir_p working_directory(mini_environment)
-
-    Dir.chdir(working_directory(mini_environment)) do
-      if Dir.empty?('.')
-        RubyTerraform.init(
-          backend: true,
-          from_module: source,
-          backend_config: {
-            address: terraform_backend_address(mini_environment)
-          },
-          plugin_dir: terraform_plugin_dir
-        )
-      end
-
-      yield
-    end
-  end
-
-  def terraform_backend_address(mini_environment)
-    (
-      'http://localhost:3000' +
-      Rails
-        .application
-        .routes
-        .url_helpers
-        .mini_environment_terraform_http_backend_path(
-          mini_environment
-        )
-    )
-  end
-
-  def terraform_plugin_dir
-    ENV['PATH'].split(':').first
-  end
-end
diff --git a/app/models/backends/terraform_aws.rb b/app/models/backends/terraform_aws.rb
index 98b1f41..45c766b 100644
--- a/app/models/backends/terraform_aws.rb
+++ b/app/models/backends/terraform_aws.rb
@@ -35,8 +35,6 @@
 require 'ruby_terraform'
 
 class Backends::TerraformAws < ApplicationRecord
-  include Backends::Terraform
-
   has_many :mini_environments, as: :backend
 
   self.table_name = 'terraform_aws_backends'
@@ -65,7 +63,7 @@ class Backends::TerraformAws < ApplicationRecord
   def start(mini_environment)
     logger.info "Setting up #{mini_environment.name}"
 
-    with_terraform(mini_environment, 'terraform/aws') do
+    within_terraform_working_directory(mini_environment) do
       RubyTerraform.apply(
         vars: terraform_variables(mini_environment),
         auto_approve: true
@@ -74,7 +72,7 @@ class Backends::TerraformAws < ApplicationRecord
   end
 
   def destroy(mini_environment)
-    with_terraform(mini_environment, 'terraform/aws') do
+    within_terraform_working_directory(mini_environment) do
       RubyTerraform.destroy(
         vars: terraform_variables(mini_environment),
         force: true
@@ -82,6 +80,13 @@ class Backends::TerraformAws < ApplicationRecord
     end
   end
 
+  def within_terraform_working_directory(mini_environment, &block)
+    TerraformWorkingDirectory.new(
+      "mini_environment/#{mini_environment.id}",
+      'terraform/aws'
+    ).within_working_directory(&block)
+  end
+
   def signon_url(mini_environment)
     "https://signon.#{mini_environment.name.parameterize}.#{domain}"
   end
diff --git a/app/models/backends/terraform_libvirt.rb b/app/models/backends/terraform_libvirt.rb
index 147c27d..f108560 100644
--- a/app/models/backends/terraform_libvirt.rb
+++ b/app/models/backends/terraform_libvirt.rb
@@ -33,8 +33,6 @@
 require 'ruby_terraform'
 
 class Backends::TerraformLibvirt < ApplicationRecord
-  include Backends::Terraform
-
   has_many :mini_environments, as: :backend
 
   self.table_name = 'terraform_libvirt_backends'
@@ -65,7 +63,7 @@ class Backends::TerraformLibvirt < ApplicationRecord
   def start(mini_environment)
     logger.info "Setting up #{mini_environment.name}"
 
-    with_terraform(mini_environment, 'terraform/libvirt') do
+    within_terraform_working_directory(mini_environment) do
       RubyTerraform.apply(
         vars: terraform_variables(mini_environment),
         auto_approve: true
@@ -74,7 +72,7 @@ class Backends::TerraformLibvirt < ApplicationRecord
   end
 
   def destroy(mini_environment)
-    with_terraform(mini_environment, 'terraform/libvirt') do
+    within_terraform_working_directory(mini_environment) do
       RubyTerraform.destroy(
         vars: terraform_variables(mini_environment),
         force: true
@@ -82,6 +80,13 @@ class Backends::TerraformLibvirt < ApplicationRecord
     end
   end
 
+  def within_terraform_working_directory(mini_environment, &block)
+    TerraformWorkingDirectory.new(
+      "mini_environment/#{mini_environment.id}",
+      'terraform/libvirt'
+    ).within_working_directory(&block)
+  end
+
   def signon_url(mini_environment)
     "https://signon.#{mini_environment.name.parameterize}.#{domain}"
   end