Add a new AWS backend using Amazon Machine Images

The existing AWS backend uses system containers backed on to the AWS
hosted NFS service (EFS). This has some advantages, but also some
disadvantages.

Using the EFS service allows building a container on one instance,
with the state being held on the EFS, and then launching a new
instance to run the container. Using EFS also provides persistence, at
least beyond individual EC2 instances.

However, build performance when using EFS is poor compared with a
local store without the overhead of the network latency. Additionally,
the startup speed of the container running off EFS is slow compared to
local storage.

This backend doesn't use EFS, instead the Guix store sits on instance
storage. Rather than using a system container for a Mini Environment,
an Amazon Machine Image (AMI) is built instead. The fast local storage
makes builds faster, and using EBS storage for the Mini Envirnoments
as well as not having the overhead of starting Ubuntu, then starting
the container also makes startup faster.

11 files changed, 1085 insertions, 8 deletions

diff --git a/app/controllers/backends/terraform_aws_using_ami_controller.rb b/app/controllers/backends/terraform_aws_using_ami_controller.rb
new file mode 100644
index 0000000..9fbe115
--- /dev/null
+++ b/app/controllers/backends/terraform_aws_using_ami_controller.rb
@@ -0,0 +1,118 @@
+# GOV.UK Mini Environment Admin
+# Copyright © 2018, 2019  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/>.
+
+class Backends::TerraformAwsUsingAmiController < ApplicationController
+  def new
+    @backend = Backends::TerraformAws.new
+  end
+
+  def create
+    backend = Backends::TerraformAwsUsingAmi.create(create_params)
+
+    flash[:success] = "Backend #{backend.label} created"
+
+    redirect_to terraform_aws_using_ami_backend_path(backend)
+  end
+
+  def update
+    @backend = Backends::TerraformAwsUsingAmi.update(
+      params[:id],
+      update_params
+    )
+
+    flash[:success] = "Backend #{@backend.label} updated"
+
+    render :show
+  end
+
+  def show
+    @backend = Backends::TerraformAwsUsingAmi.find(params[:id])
+  end
+
+  def destroy
+    backend = Backends::TerraformAwsUsingAmi.find(params[:id])
+
+    if @backend.mini_environments.empty?
+      flash[:success] = "Backend #{backend.label} deleted"
+      backend.delete
+    else
+      flash[:error] = "Unable to delete backend, as mini environments using this backend still exist."
+    end
+
+    redirect_to setup_path
+  end
+
+  def perform_action
+    @backend = Backends::TerraformAwsUsingAmi.find(params['id'])
+
+    action = params.require(:commit)
+
+    case action
+    when 'Destroy'
+      Backends::TerraformAwsUsingAmiJob.enqueue(@backend.id, :destroy_backend)
+
+      flash[:notice] = 'Destroying the backend'
+    when 'Stop'
+      Backends::TerraformAwsUsingAmiJob.enqueue(@backend.id, :stop_backend)
+
+      flash[:notice] = 'Stopping the backend'
+    when 'Deploy'
+      Backends::TerraformAwsUsingAmiJob.enqueue(@backend.id, :deploy_backend)
+
+      flash[:notice] = 'Deploying the backend'
+    when 'Refresh state'
+      Backends::TerraformAwsUsingAmiJob.enqueue(@backend.id, :refresh_backend_state)
+
+      flash[:notice] = 'Refreshing the backend state information'
+    else
+      flash[:error] = "Unknown action #{action}"
+    end
+
+    redirect_to terraform_aws_using_ami_backend_path(@backend)
+  end
+
+  private
+
+  def create_params
+    params
+      .require(:backends_terraform_aws)
+      .permit(
+        :label,
+        :domain,
+        :aws_region,
+        :vpc_id,
+        :route_53_zone_id,
+        :aws_access_key_id,
+        :aws_secret_access_key,
+        :ssh_public_key,
+        :ssh_private_key
+      )
+  end
+
+  def update_params
+    params
+      .require(:backends_terraform_aws)
+      .permit(
+        :label,
+        :aws_access_key_id,
+        :aws_secret_access_key
+      )
+  end
+end
diff --git a/app/controllers/govuk_guix/revisions_controller.rb b/app/controllers/govuk_guix/revisions_controller.rb
index e4e1b52..1544bc1 100644
--- a/app/controllers/govuk_guix/revisions_controller.rb
+++ b/app/controllers/govuk_guix/revisions_controller.rb
@@ -40,7 +40,8 @@ class GovukGuix::RevisionsController < ApplicationController
       options = {}
     else
       # Assume that the AWS backend is in use
-      backend = Backends::TerraformAws.first
+      backend = Backends::TerraformAwsUsingAmi.first ||
+                Backends::TerraformAws.first
 
       options = {
         backend_type_and_id: backend.type_and_id
diff --git a/app/jobs/backends/terraform_aws_using_ami_job.rb b/app/jobs/backends/terraform_aws_using_ami_job.rb
new file mode 100644
index 0000000..1412e8c
--- /dev/null
+++ b/app/jobs/backends/terraform_aws_using_ami_job.rb
@@ -0,0 +1,46 @@
+# GOV.UK Mini Environment Admin
+# Copyright © 2018, 2019  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/>.
+
+class Backends::TerraformAwsUsingAmiJob < Que::Job
+  def run(terraform_aws_using_ami_backend_id, action)
+    ActiveRecord::Base.transaction do
+      @backend = Backends::TerraformAwsUsingAmi.find(
+        terraform_aws_using_ami_backend_id
+      )
+
+      @backend.send(action)
+
+      finish
+    end
+  end
+
+  def self.job_title(que_job)
+    que_job.args.last.titleize
+  end
+
+  def self.jobs(terraform_aws_using_ami_backend_id)
+    QueJob
+      .where(
+        job_class: name
+      ).where(
+        "args->>0 = '#{terraform_aws_using_ami_backend_id}'"
+      )
+  end
+end
diff --git a/app/models/backends.rb b/app/models/backends.rb
index 526ae76..2a3bceb 100644
--- a/app/models/backends.rb
+++ b/app/models/backends.rb
@@ -1,5 +1,5 @@
 # GOV.UK Mini Environment Admin
-# Copyright © 2018  Christopher Baines <mail@cbaines.net>
+# Copyright © 2018, 2019  Christopher Baines <mail@cbaines.net>
 #
 # This file is part of the GOV.UK Mini Environment Admin.
 #
@@ -26,6 +26,7 @@ module Backends
   def self.classes
     [
       Backends::TerraformAws,
+      Backends::TerraformAwsUsingAmi,
       Backends::TerraformLibvirt
     ]
   end
diff --git a/app/models/backends/terraform_aws.rb b/app/models/backends/terraform_aws.rb
index d3d56d1..64d24ef 100644
--- a/app/models/backends/terraform_aws.rb
+++ b/app/models/backends/terraform_aws.rb
@@ -1,5 +1,5 @@
 # GOV.UK Mini Environment Admin
-# Copyright © 2018  Christopher Baines <mail@cbaines.net>
+# Copyright © 2018, 2019  Christopher Baines <mail@cbaines.net>
 #
 # This file is part of the GOV.UK Mini Environment Admin.
 #
@@ -47,7 +47,7 @@ class Backends::TerraformAws < ApplicationRecord
   self.table_name = 'terraform_aws_backends'
 
   def self.label
-    'Amazon Web Services'
+    'Amazon Web Services (using EFS)'
   end
 
   def self.available?
diff --git a/app/models/backends/terraform_aws_using_ami.rb b/app/models/backends/terraform_aws_using_ami.rb
new file mode 100644
index 0000000..bb9f90d
--- /dev/null
+++ b/app/models/backends/terraform_aws_using_ami.rb
@@ -0,0 +1,90 @@
+# GOV.UK Mini Environment Admin
+# Copyright © 2018, 2019  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/>.
+
+# == Schema Information
+#
+# Table name: terraform_aws_backends
+#
+#  id                    :integer          not null, primary key
+#  label                 :string
+#  aws_region            :string
+#  aws_access_key_id     :string
+#  aws_secret_access_key :string
+#  created_at            :datetime         not null
+#  updated_at            :datetime         not null
+#  domain                :string
+#  route_53_zone_id      :string           not null
+#  vpc_id                :string           not null
+#  ssh_public_key        :string
+#  ssh_private_key       :string
+#
+
+require 'ruby_terraform'
+
+class Backends::TerraformAwsUsingAmi < ApplicationRecord
+  include MiniEnvironmentMethods
+  include BackendMethods
+
+  has_many :mini_environments, as: :backend
+
+  self.table_name = 'terraform_aws_using_ami_backends'
+
+  def self.label
+    'Amazon Web Services (using AMIs)'
+  end
+
+  def self.available?
+    File.exist? "#{ENV['PATH'].split(':').first}/terraform-provider-aws"
+  end
+
+  def type_and_id
+    "#{self.class.name}=#{id}"
+  end
+
+  def common_terraform_variables
+    {
+      aws_access_key: aws_access_key_id,
+      aws_secret_key: aws_secret_access_key,
+      aws_region: aws_region,
+      ssh_private_key: ssh_private_key,
+      aws_route_53_zone_id: route_53_zone_id
+    }
+  end
+
+  def build_remote_host
+    RemoteHost.new(
+      'ubuntu',
+      backend_latest_terraform_state.output_value('guix_daemon_public_dns'),
+      ssh_private_key
+    )
+  end
+
+  def terraform_state_id
+    "backend/terraform_aws_using_ami/#{id}"
+  end
+
+  def guix_public_key
+    "(entry #{File.read("/etc/guix/signing-key.pub")} (tag (guix import)))"
+  rescue Errno::ENOENT
+    # This is optional, as if it doesn't exist, it means that `guix
+    # copy` won't be used
+    ''
+  end
+end
diff --git a/app/models/backends/terraform_aws_using_ami/backend_methods.rb b/app/models/backends/terraform_aws_using_ami/backend_methods.rb
new file mode 100644
index 0000000..10bf872
--- /dev/null
+++ b/app/models/backends/terraform_aws_using_ami/backend_methods.rb
@@ -0,0 +1,146 @@
+# GOV.UK Mini Environment Admin
+# Copyright © 2018, 2019  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/>.
+
+module Backends::TerraformAwsUsingAmi::BackendMethods
+  def create_data_snapshot
+    GovukGuix::CreateDataSnapshotJob.enqueue(
+      backend_type: self.class.name,
+      backend_id: id
+    )
+  end
+
+  def backend_terraform_variables
+    public_ip_addresses = ENV[
+      'GOVUK_MINI_ENVIRONMENT_ADMIN_PUBLIC_IP_ADDRESSES'
+    ].split(',')
+
+    raise 'missing public ip addresses' if public_ip_addresses.nil?
+
+    egress_cidr_blocks = public_ip_addresses.map { |x| "#{x}/32" }
+
+    common_terraform_variables.merge(
+      aws_vpc_id: vpc_id,
+      ssh_public_key: ssh_public_key,
+      backend_slug: label.parameterize,
+      mini_environment_admin_guix_public_key: guix_public_key,
+      mini_environment_admin_egress_cidr_blocks: egress_cidr_blocks
+    )
+  end
+
+  def deploy_backend
+    within_backend_terraform_working_directory do
+      RubyTerraform.apply(
+        vars: backend_terraform_variables,
+        auto_approve: true
+      )
+    end
+  end
+
+  def refresh_backend_state
+    within_backend_terraform_working_directory do
+      RubyTerraform.refresh(
+        vars: backend_terraform_variables
+      )
+    end
+  end
+
+  def destroy_backend
+    within_backend_terraform_working_directory do
+      RubyTerraform.destroy(
+        vars: backend_terraform_variables,
+        force: true
+      )
+    end
+  end
+
+  def stop_backend
+    within_backend_terraform_working_directory do
+      RubyTerraform.destroy(
+        vars: backend_terraform_variables,
+        target: 'aws_spot_instance_request.main',
+        force: true
+      )
+    end
+  end
+
+  def in_use_store_paths
+    [
+      GovukGuix::Revision.where(archived: false).pluck(:store_path),
+      available_data_snapshots.pluck(:store_path),
+      mini_environments
+        .where(archived: false)
+        .pluck(:backend_data)
+        .map { |x| x&.dig('build_output') }
+    ].flatten.compact
+  end
+
+  def update_guix_gcroots
+    GovukGuix::UpdateGcrootsDirectory.set_in_use_store_paths(
+      in_use_store_paths,
+      run_remotely_on_host: build_remote_host
+    )
+  end
+
+  def add_in_use_store_path(store_path)
+    GovukGuix::UpdateGcrootsDirectory.add_store_path(
+      store_path,
+      run_remotely_on_host: build_remote_host
+    )
+  end
+
+  def within_backend_terraform_working_directory(&block)
+    with_advisory_lock(
+      "terraform"
+    ) do
+      TerraformWorkingDirectory.new(
+        terraform_state_id,
+        'terraform/aws_using_ami/backend'
+      ).within_working_directory(&block)
+    end
+  end
+
+  def available_data_snapshots
+    GovukGuix::DataSnapshot.where(backend: self)
+  end
+
+  def backend_terraform_states
+    TerraformState.where(
+      state_id: terraform_state_id
+    )
+  end
+
+  def backend_latest_terraform_state
+    backend_terraform_states.order(:id).last
+  end
+
+  def status
+    latest_terraform_state = backend_terraform_states.order(:id).last
+
+    running = (
+      latest_terraform_state &&
+      (latest_terraform_state.output_value('backend_up') == 'true')
+    )
+
+    {
+      running: running,
+      updated_at: latest_terraform_state.try(:created_at)
+    }
+  end
+end
diff --git a/app/models/backends/terraform_aws_using_ami/mini_environment_methods.rb b/app/models/backends/terraform_aws_using_ami/mini_environment_methods.rb
new file mode 100644
index 0000000..839bc3b
--- /dev/null
+++ b/app/models/backends/terraform_aws_using_ami/mini_environment_methods.rb
@@ -0,0 +1,117 @@
+# GOV.UK Mini Environment Admin
+# Copyright © 2018, 2019  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/>.
+
+module Backends::TerraformAwsUsingAmi::MiniEnvironmentMethods
+  def build(mini_environment)
+    slug = mini_environment.name.parameterize
+
+    GovukGuix::BuildMiniEnvironment.build(
+      mini_environment.id,
+      services: mini_environment.services.map(&:build_argument_string),
+      arguments: {
+        type: 'aws-packer-ami',
+        base_os: 'aws',
+        ami_name: "govuk-mini-environment-admin-#{slug}",
+        app_domain: "#{slug}.#{domain}",
+        web_domain: "www.#{slug}.#{domain}",
+        use_https: 'certbot',
+        signon_instance_name: slug,
+        admin_environment_label: mini_environment.name,
+        use_error_pages: 'true',
+        origin_basic_auth: "#{slug}=#{slug}",
+      },
+      run_remotely_on_host: mini_environment.backend.build_remote_host
+    )
+  end
+
+  def start(mini_environment)
+    logger.info "Setting up #{mini_environment.name}"
+
+    within_terraform_working_directory(mini_environment) do
+      RubyTerraform.apply(
+        vars: terraform_variables(mini_environment),
+        auto_approve: true
+      )
+    end
+  end
+
+  def destroy(mini_environment)
+    within_terraform_working_directory(mini_environment) do
+      RubyTerraform.destroy(
+        vars: terraform_variables(mini_environment),
+        force: true
+      )
+    end
+  end
+
+  def refresh(mini_environment)
+    within_terraform_working_directory(mini_environment) do
+      RubyTerraform.refresh(
+        vars: terraform_variables(mini_environment)
+      )
+    end
+  end
+
+  def terraform_states(mini_environment)
+    TerraformState.where(
+      state_id: mini_environment_state_id(mini_environment)
+    )
+  end
+
+  def within_terraform_working_directory(mini_environment, &block)
+    with_advisory_lock(
+      "terraform"
+    ) do
+      TerraformWorkingDirectory.new(
+        mini_environment_state_id(mini_environment),
+        'terraform/aws_using_ami/mini_environment'
+      ).within_working_directory(&block)
+    end
+  end
+
+  def mini_environment_state_id(mini_environment)
+    "mini_environment/#{mini_environment.id}"
+  end
+
+  def signon_url(mini_environment)
+    "https://signon.#{mini_environment.name.parameterize}.#{domain}"
+  end
+
+  def terraform_variables(mini_environment)
+    credentials = TerraformHttpBackendController.credentials
+
+    ami_id = mini_environment.backend_data['build_output'].split(' ')[1]
+
+    common_terraform_variables.merge(
+      slug: mini_environment.name.parameterize,
+      ami_id: ami_id,
+      backend_remote_state_address: (
+        Plek.new.external_url_for('mini-environment-admin') +
+        Rails
+          .application
+          .routes
+          .url_helpers
+          .terraform_http_backend_path(terraform_state_id)
+      ),
+      backend_remote_state_username: credentials[:name],
+      backend_remote_state_password: credentials[:password]
+    )
+  end
+end
diff --git a/app/services/govuk_guix/build_mini_environment.rb b/app/services/govuk_guix/build_mini_environment.rb
index 9cada20..a87c4da 100644
--- a/app/services/govuk_guix/build_mini_environment.rb
+++ b/app/services/govuk_guix/build_mini_environment.rb
@@ -72,12 +72,16 @@ module GovukGuix::BuildMiniEnvironment
       run_remotely_on_host: remote_host
     )
 
-    build_output = output.last.strip
-
-    raise 'InvalidOutput' unless build_output.starts_with? '/gnu/store'
-
+    last_non_empty_line = output.reverse.find do |line|
+      !line.strip.empty?
+    end
+    build_output = last_non_empty_line.strip
     logger.debug(self.class) { "build_output: #{build_output}" }
 
+    unless options[:arguments][:type] == 'aws-packer-ami'
+      raise 'InvalidOutput' unless build_output.starts_with? '/gnu/store'
+    end
+
     mini_environment.update(
       backend_data: {
         build_output: build_output
diff --git a/app/views/backends/terraform_aws_using_ami/new.html.erb b/app/views/backends/terraform_aws_using_ami/new.html.erb
new file mode 100644
index 0000000..929d69f
--- /dev/null
+++ b/app/views/backends/terraform_aws_using_ami/new.html.erb
@@ -0,0 +1,192 @@
+<%#
+
+GOV.UK Mini Environment Admin
+Copyright © 2018, 2019  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/>.
+
+%>
+
+<a href="<%= setup_path %>" class="btn btn-lg btn-default pull-right">
+  Back to setup
+</a>
+
+<h1>Create a new AWS backend</h1>
+
+<div class="row">
+  <div class="col-md-10">
+    <%= form_with(model: @backend,
+                  url: { action: "create" },
+                  html: { class: "form-horizontal" }) do |f|
+    %>
+
+      <div class="form-group form-group-lg">
+        <%= f.label :label, class: 'col-sm-4 control-label' %>
+        <div class="col-sm-8">
+          <%= f.text_field(
+            :label,
+            class: 'form-control',
+            placeholder: 'Label for this backend'
+          ) %>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label :domain, class: 'col-sm-4 control-label' %>
+        <div class="col-sm-8">
+          <%= f.text_field(
+            :domain,
+            class: 'form-control',
+            placeholder: 'Domain within which to host mini environments'
+          ) %>
+          <span class="help-block">
+            <p>
+              For example, if you entered <samp>example.com</samp> for
+              the backend domain, and then created a mini environment
+              called "Test" using this backend, then the application
+              domain for the mini environment would be
+              <samp>test.example.com</samp>.
+            </p>
+            <p>
+              A Route53 Hosted Zone will be created for this domain,
+              and records added for the mini environments.
+            </p>
+          </span>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label :aws_region, 'AWS Region', class: 'col-sm-4 control-label' %>
+        <div class="col-sm-8">
+          <%= f.text_field(
+            :aws_region,
+            class: 'form-control',
+            placeholder: 'What region to use'
+          ) %>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label(
+          :vpc_id,
+          'VPC ID',
+          class: 'col-sm-4 control-label'
+        ) %>
+        <div class="col-sm-8">
+          <%= f.text_field(
+            :vpc_id,
+            class: 'form-control',
+            placeholder: 'The ID of the VPC (Virtual Private Cloud) to use'
+          ) %>
+          <span class="help-block">
+            <p>
+              This VPC (Virtual Private Cloud) should be the one to
+              use for all resources.
+            </p>
+          </span>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label(
+          :route_53_zone_id,
+          'Route 53 Zone ID',
+          class: 'col-sm-4 control-label'
+        ) %>
+        <div class="col-sm-8">
+          <%= f.text_field(
+            :route_53_zone_id,
+            class: 'form-control',
+            placeholder: 'The ID of the Route 53 Zone to use'
+          ) %>
+          <span class="help-block">
+            <p>
+              This zone should be authoritive for the domain this
+              backend is using. Entries in this zone will be created
+              for the mini environments.
+            </p>
+          </span>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label :aws_access_key_id, 'AWS Access Key ID', class: 'col-sm-4 control-label' %>
+        <div class="col-sm-8">
+          <%= f.text_field(
+            :aws_access_key_id,
+            class: 'form-control',
+          ) %>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label :aws_secret_access_key, 'AWS Secret Access Key', class: 'col-sm-4 control-label' %>
+        <div class="col-sm-8">
+          <%= f.password_field(
+            :aws_secret_access_key,
+            class: 'form-control',
+          ) %>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label(
+          :ssh_public_key,
+          'SSH Key, public part',
+          class: 'col-sm-4 control-label'
+        ) %>
+        <div class="col-sm-8">
+          <%= f.text_area(
+            :ssh_public_key,
+            class: 'form-control',
+            placeholder: 'The public part of the SSH key to use'
+          ) %>
+          <span class="help-block">
+            <p>
+            </p>
+          </span>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label(
+          :ssh_private_key,
+          'SSH Key, private part',
+          class: 'col-sm-4 control-label'
+        ) %>
+        <div class="col-sm-8">
+          <%= f.text_area(
+            :ssh_private_key,
+            class: 'form-control',
+            placeholder: 'The private part of the SSH key to use'
+          ) %>
+          <span class="help-block">
+            <p>
+            </p>
+          </span>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <div class="col-sm-offset-4 col-sm-8">
+          <%= f.submit "Create", class: 'btn btn-lg btn-success' %>
+        </div>
+      </div>
+    <% end %>
+  </div>
+</div>
diff --git a/app/views/backends/terraform_aws_using_ami/show.html.erb b/app/views/backends/terraform_aws_using_ami/show.html.erb
new file mode 100644
index 0000000..14810d1
--- /dev/null
+++ b/app/views/backends/terraform_aws_using_ami/show.html.erb
@@ -0,0 +1,362 @@
+<%#
+
+GOV.UK Mini Environment Admin
+Copyright © 2018, 2019  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/>.
+
+%>
+
+<a href="<%= setup_path %>" class="btn btn-lg btn-default pull-right">
+  Back to Setup
+</a>
+
+<h1>Backend: <%= @backend.label %></h1>
+<% status = @backend.status %>
+
+<br>
+
+<div class="row">
+  <div class="col-md-3">
+
+    <div class="panel panel-default">
+      <div class="panel-heading">
+        Current Status<br>
+        <small>updated at <%= status[:updated_at] %></small>
+      </div>
+      <div class="panel-body">
+        <% if status[:running] %>
+          <div class="alert alert-success text-center"
+               role="alert"
+               style="margin-bottom: 0px;">
+            Backend available
+          </div>
+        <% else %>
+          <div class="alert alert-warning text-center"
+               role="alert"
+               style="margin-bottom: 0px;">
+            Backend down
+          </div>
+        <% end %>
+
+        <br>
+        <a href="<%= terraform_http_backend_show_history_path(
+                 @backend.terraform_state_id
+                 ) %>">
+          View Terraform state information
+        </a>
+      </div>
+    </div>
+
+    <%= form_with(
+      url: perform_action_terraform_aws_using_ami_backend_path(@backend),
+      local: true,
+      method: "post"
+    ) do %>
+
+      <div class="panel panel-default">
+        <div class="panel-heading">Actions</div>
+
+        <ul class="list-group">
+          <li class="list-group-item">
+            <%= submit_tag('Deploy',
+                           role: 'button',
+                           style: 'margin-bottom: 5px;',
+                           class: 'btn btn-lg btn-success btn-block')
+            %>
+            <p class="list-group-item-text">
+              Run Terraform to deploy this backend, ensuring everything
+              is setup to create new mini environments.
+            </p>
+          </li>
+          <li class="list-group-item">
+            <%= submit_tag("Stop",
+                           role: 'button',
+                           style: 'margin-bottom: 5px;',
+                           class: 'btn btn-lg btn-warning btn-block')
+            %>
+            <p class="list-group-item-text">
+              Run Terraform to stop this backend, terminating the
+              build machine used to build new mini
+              environments. Existing environments will continue to
+              run, but new environments cannot be created.
+            </p>
+          </li>
+          <li class="list-group-item">
+            <%= submit_tag("Destroy",
+                           role: 'button',
+                           style: 'margin-bottom: 5px;',
+                           class: 'btn btn-lg btn-danger btn-block')
+            %>
+            <p class="list-group-item-text">
+              Run Terraform to destroy this backend, note that this will
+              remove all cached data and disrupt all mini environments
+              using this backend.
+            </p>
+          </li>
+          <li class="list-group-item">
+            <%= submit_tag("Refresh state",
+                           role: 'button',
+                           style: 'margin-bottom: 5px;',
+                           class: 'btn btn-lg btn-info btn-block')
+            %>
+            <p class="list-group-item-text">
+              Run Terraform to refresh the state information for this
+              backend.
+            </p>
+          </li>
+        </ul>
+      </div>
+    <% end %>
+  </div>
+  <div class="col-md-9">
+    <%= render(
+      partial: 'shared/jobs',
+      locals: {
+        jobs: Backends::TerraformAwsJob.jobs(@backend.id).order(id: :desc)
+      }
+    ) %>
+  </div>
+</div>
+
+<div class="row">
+  <div class="col-md-8">
+    <h3>Update details</h3>
+    <br>
+
+    <%= form_with(model: @backend,
+                  url: { action: "update" },
+                  html: { class: "form-horizontal" }) do |f|
+    %>
+
+      <div class="form-group form-group-lg">
+        <%= f.label :label, class: 'col-sm-4 control-label' %>
+        <div class="col-sm-8">
+          <%= f.text_field(
+            :label,
+            class: 'form-control',
+            placeholder: 'Label for this backend'
+          ) %>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label :domain, class: 'col-sm-4 control-label' %>
+        <div class="col-sm-8">
+          <%= f.text_field(
+            :domain,
+            class: 'form-control',
+            placeholder: 'Domain within which to host mini environments',
+            readonly: true
+          ) %>
+          <span class="help-block">
+            <p>
+              For example, if you entered <samp>example.com</samp> for
+              the backend domain, and then created a mini environment
+              called "Test" using this backend, then the application
+              domain for the mini environment would be
+              <samp>test.example.com</samp>.
+            </p>
+            <p>
+              A Route53 Hosted Zone will be created for this domain,
+              and records added for the mini environments.
+            </p>
+          </span>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label :aws_region, 'AWS Region', class: 'col-sm-4 control-label' %>
+        <div class="col-sm-8">
+          <%= f.text_field(
+            :aws_region,
+            class: 'form-control',
+            placeholder: 'What region to use',
+            readonly: true,
+          ) %>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label(
+          :vpc_id,
+          'VPC ID',
+          class: 'col-sm-4 control-label'
+        ) %>
+        <div class="col-sm-8">
+          <%= f.text_field(
+            :vpc_id,
+            class: 'form-control',
+            placeholder: 'The ID of the VPC (Virtual Private Cloud) to use',
+            readonly: true
+          ) %>
+          <span class="help-block">
+            <p>
+              This VPC (Virtual Private Cloud) should be the one to
+              use for all resources.
+            </p>
+          </span>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label(
+          :route_53_zone_id,
+          'Route 53 Zone ID',
+          class: 'col-sm-4 control-label'
+        ) %>
+        <div class="col-sm-8">
+          <%= f.text_field(
+            :route_53_zone_id,
+            class: 'form-control',
+            placeholder: 'The ID of the Route 53 Zone to use',
+            readonly: true
+          ) %>
+          <span class="help-block">
+            <p>
+              This zone should be authoritive for the domain this
+              backend is using. Entries in this zone will be created
+              for the mini environments.
+            </p>
+          </span>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label :aws_access_key_id, 'AWS Access Key ID', class: 'col-sm-4 control-label' %>
+        <div class="col-sm-8">
+          <%= f.text_field(
+            :aws_access_key_id,
+            class: 'form-control',
+          ) %>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label :aws_secret_access_key, 'AWS Secret Access Key', class: 'col-sm-4 control-label' %>
+        <div class="col-sm-8">
+          <%= f.password_field(
+            :aws_secret_access_key,
+            class: 'form-control',
+            placeholder: 'Secret key hidden',
+          ) %>
+          <span id="helpBlock" class="help-block">
+            The AWS Secret Access Key is not accessible once entered.
+          </span>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label(
+          :ssh_public_key,
+          'SSH Key, public part',
+          class: 'col-sm-4 control-label'
+        ) %>
+        <div class="col-sm-8">
+          <%= f.text_area(
+            :ssh_public_key,
+            class: 'form-control',
+            placeholder: 'The public part of the SSH key to use',
+            readonly: true
+          ) %>
+          <span class="help-block">
+            <p>
+            </p>
+          </span>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <%= f.label(
+          :ssh_private_key,
+          'SSH Key, private part',
+          class: 'col-sm-4 control-label'
+        ) %>
+        <div class="col-sm-8">
+          <%= text_area_tag(
+            :ssh_private_key,
+            'Secret key hidden',
+            class: 'form-control',
+            disabled: true
+          ) %>
+          <span class="help-block">
+            <p>
+            </p>
+          </span>
+        </div>
+      </div>
+
+      <div class="form-group form-group-lg">
+        <div class="col-sm-offset-2 col-sm-10">
+          <%= f.submit "Save", class: 'btn btn-lg btn-success' %>
+        </div>
+      </div>
+    <% end %>
+  </div>
+  <div class="col-md-4">
+    <h3>Delete backend</h3>
+    <br>
+
+    <% unless @backend.mini_environments.empty? %>
+      <p>
+        Unable to delete backend, as mini environments using this
+        backend still exist.
+      </p>
+
+      <p>
+        To delete this backend, first delete all the mini environments
+        using it.
+      </p>
+    <% end %>
+
+    <%= form_with(model: @backend,
+                  url: { action: "destroy" },
+                  html: { class: "form-horizontal", method: :delete }) do |f|
+    %>
+      <%= f.submit(
+        "Delete",
+        class: (
+          'btn btn-lg btn-danger' +
+          (@backend.mini_environments.empty? ? '' : ' disabled')
+        )
+      ) %>
+    <% end %>
+
+  </div>
+</div>
+
+<h3>Mini environments</h3>
+
+<table class="table table-striped">
+  <tr>
+    <th>Name</th>
+    <th></th>
+  </tr>
+  <% @backend.mini_environments.each do |mini_environment| %>
+    <tr>
+      <td><%= mini_environment.name %></td>
+      <td>
+        <a class="btn btn-default btn-lg pull-right"
+           role="button"
+           href="<%= mini_environment_path(mini_environment) %>">
+          Show details
+        </a>
+      </td>
+    </tr>
+  <% end %>
+</table>