Added ability to push CF template to S3 (#239)

* added ability to push CF template to S3

* code style fixes

* using InteractiveLogger; include timestamp in uploaded S3 object name; fixed code style

* test the s3client.put_object gets called if the template_s3_bucket is configured

* improved tests

lib/moonshot/controller_config.rb

@@ -26,6 +26,7 @@ class ControllerConfig
     attr_accessor :ssh_command
     attr_accessor :ssh_config
     attr_accessor :ssh_instance
+    attr_accessor :template_s3_bucket
 
     def initialize
       @default_parameter_source = AskUserSource.new

lib/moonshot/stack.rb

@@ -176,14 +176,39 @@ def get_stack(name)
       raise "Could not describe stack: #{name}"
     end
 
+    def upload_template_to_s3
+      unless @config.template_s3_bucket
+        raise 'The S3 bucket to store the template in is not configured.'
+      end
+
+      s3_object_key = "#{@name}-#{Time.now.getutc.to_i}-#{File.basename(template.filename)}"
+      template_url = "http://#{@config.template_s3_bucket}.s3.amazonaws.com/#{s3_object_key}"
+
+      @ilog.start "Uploading template to #{template_url}" do |s|
+        s3_client.put_object(
+          bucket: @config.template_s3_bucket,
+          key: s3_object_key,
+          body: template.body
+        )
+        s.success "Template has been uploaded successfully to #{template_url}"
+      end
+
+      template_url
+    end
+
     def create_stack
-      cf_client.create_stack(
+      parameters = {
         stack_name: @name,
-        template_body: template.body,
         capabilities: %w(CAPABILITY_IAM CAPABILITY_NAMED_IAM),
         parameters: @config.parameters.values.map(&:to_cf),
         tags: make_tags
-      )
+      }
+      if @config.template_s3_bucket
+        parameters[:template_url] = upload_template_to_s3
+      else
+        parameters[:template_body] = template.body
+      end
+      cf_client.create_stack(parameters)
     rescue Aws::CloudFormation::Errors::AccessDenied
       raise 'You are not authorized to perform create_stack calls.'
     end
@@ -195,14 +220,20 @@ def new_change_set
         Time.now.utc.to_i.to_s
       ].join('-')
 
-      cf_client.create_change_set(
+      parameters = {
         change_set_name: change_set_name,
         description: "Moonshot update command for application '#{Moonshot.config.app_name}'",
         stack_name: @name,
-        template_body: template.body,
         capabilities:  %w(CAPABILITY_IAM CAPABILITY_NAMED_IAM),
         parameters: @config.parameters.values.map(&:to_cf)
-      )
+      }
+      if @config.template_s3_bucket
+        parameters[:template_url] = upload_template_to_s3
+      else
+        parameters[:template_body] = template.body
+      end
+
+      cf_client.create_change_set(parameters)
 
       change_set_name
     end
@@ -289,7 +320,12 @@ def doctor_check_template_exists
     end
 
     def doctor_check_template_against_aws
-      cf_client.validate_template(template_body: template.body)
+      if @config.template_s3_bucket
+        parameters[:template_url] = upload_template_to_s3
+      else
+        parameters[:template_body] = template.body
+      end
+      cf_client.validate_template(parameters)
       success('CloudFormation template is valid.')
     rescue => e
       critical('Invalid CloudFormation template!', e.message)

spec/moonshot/stack_spec.rb

@@ -5,6 +5,7 @@
   let(:ilog) { Moonshot::InteractiveLoggerProxy.new(log) }
   let(:parent_stacks) { [] }
   let(:cf_client) { instance_double(Aws::CloudFormation::Client) }
+  let(:s3_client) { instance_double(Aws::S3::Client) }
 
   let(:config) { Moonshot::ControllerConfig.new }
   before(:each) do
@@ -14,6 +15,7 @@
     config.parent_stacks = parent_stacks
 
     allow(Aws::CloudFormation::Client).to receive(:new).and_return(cf_client)
+    allow(Aws::S3::Client).to receive(:new).and_return(s3_client)
   end
 
   subject { described_class.new(config) }
@@ -23,9 +25,9 @@
     let(:stack_exists) { false }
 
     before(:each) do
-      expect(ilog).to receive(:start).and_yield(step)
+      expect(ilog).to receive(:start).at_least(:once).and_yield(step)
       expect(subject).to receive(:stack_exists?).and_return(stack_exists)
-      expect(step).to receive(:success)
+      expect(step).to receive(:success).at_least(:once)
     end
 
     context 'when the stack creation takes too long' do
@@ -88,10 +90,40 @@
 
       it 'should call CreateStack, then wait for completion' do
         config.additional_tag = 'ah_stage'
+        expect(s3_client).not_to receive(:put_object)
         expect(cf_client).to receive(:create_stack)
           .with(hash_including(expected_create_stack_options))
         subject.create
       end
+
+      context 'when template_s3_bucket is set' do
+        before(:each) do
+          config.template_s3_bucket = 'rspec-bucket'
+          allow(Time).to receive(:now).and_return(Time.new('2017-11-07 12:00:00 +0000'))
+        end
+
+        let(:expected_put_object_options) do
+          {
+            bucket: config.template_s3_bucket,
+            key: 'rspec-app-staging-1483228800-template.yml',
+            body: an_instance_of(String)
+          }
+        end
+
+        let(:expected_create_stack_options) do
+          {
+            template_url: 'http://rspec-bucket.s3.amazonaws.com/rspec-app-staging-1483228800-template.yml'
+          }
+        end
+
+        it 'should call put_object and create_stack with template_url parameter' do
+          expect(s3_client).to receive(:put_object)
+            .with(hash_including(expected_put_object_options))
+          expect(cf_client).to receive(:create_stack)
+            .with(hash_including(expected_create_stack_options))
+          subject.create
+        end
+      end
     end
   end