From 5fb3a15d1934f6cbd79e82cd3ca5fe79ecaeb35d Mon Sep 17 00:00:00 2001
From: Rupak Ganguly <rupakg@gmail.com>
Date: Mon, 29 Sep 2014 14:24:40 -0400
Subject: [PATCH 1/5] Enable service to use volumes_from and generate a
 volumes_from flag in the docker string.

---
 app/models/concerns/docker_runnable.rb        |  7 +++
 app/models/service.rb                         | 18 +++++++
 app/models/shared_volume.rb                   | 23 +++++++++
 .../20140929181001_create_shared_volumes.rb   | 12 +++++
 db/schema.rb                                  | 13 ++++-
 spec/models/service_spec.rb                   | 29 ++++++++++-
 spec/models/shared_volume_spec.rb             | 51 +++++++++++++++++++
 .../support/shared/docker_runnable_example.rb | 30 ++++++++---
 8 files changed, 173 insertions(+), 10 deletions(-)
 create mode 100644 app/models/shared_volume.rb
 create mode 100644 db/migrate/20140929181001_create_shared_volumes.rb
 create mode 100644 spec/models/shared_volume_spec.rb

diff --git a/app/models/concerns/docker_runnable.rb b/app/models/concerns/docker_runnable.rb
index 2821b01..961b537 100644
--- a/app/models/concerns/docker_runnable.rb
+++ b/app/models/concerns/docker_runnable.rb
@@ -12,6 +12,7 @@ def docker_run_string
       expose_flags,
       environment_flags,
       volume_flags,
+      volumes_from_flags,
       from,
       command
     ].flatten.compact.join(' ').strip
@@ -64,4 +65,10 @@ def volume_flags
     end
   end
 
+  def volumes_from_flags
+    return unless volumes_from && volumes_from.present?
+    volumes_from.map do |svol|
+      "--volumes-from #{svol.exported_from_service_name}"
+    end
+  end
 end
diff --git a/app/models/service.rb b/app/models/service.rb
index 216726d..a3f6dde 100644
--- a/app/models/service.rb
+++ b/app/models/service.rb
@@ -15,6 +15,10 @@ class Service < ActiveRecord::Base
     class_name: 'ServiceLink',
     foreign_key: 'linked_from_service_id',
     dependent: :destroy
+  has_many :volumes_from,
+    class_name: 'SharedVolume',
+    foreign_key: 'mounted_on_service_id',
+    dependent: :destroy
 
   # Only here for the dependent destroy. Want to remove any service link joins that may point
   # to this model as the 'linked_to_service'
@@ -23,6 +27,13 @@ class Service < ActiveRecord::Base
     foreign_key: 'linked_to_service_id',
     dependent: :destroy
 
+  # Only here for the dependent destroy. Want to remove any service mount joins that may point
+  # to this model as the 'mounted_on_service'
+  has_many :mounted_volumes,
+    class_name: 'SharedVolume',
+    foreign_key: 'exported_from_service_id',
+    dependent: :destroy
+
   serialize :ports, Array
   serialize :expose, Array
   serialize :environment, Array
@@ -90,6 +101,13 @@ def update_with_relationships(attributes)
       )
     end
 
+    attributes[:volumes_from] ||= []
+    attributes[:volumes_from].map! do |svol|
+      self.volumes_from.find_or_initialize_by(
+        exported_from_service_id: svol[:service_id]
+      )
+    end
+
     attributes[:volumes] ||= []
     attributes[:volumes].map! { |vol| vol.to_hash }
 
diff --git a/app/models/shared_volume.rb b/app/models/shared_volume.rb
new file mode 100644
index 0000000..4e5e392
--- /dev/null
+++ b/app/models/shared_volume.rb
@@ -0,0 +1,23 @@
+class SharedVolume < ActiveRecord::Base
+  self.table_name = 'shared_volumes'
+
+  belongs_to :exported_from_service, class_name: 'Service'
+
+  validates :exported_from_service, uniqueness: { scope: :mounted_on_service_id }, presence: true
+  validate :cannot_mount_self
+
+  def exported_from_service_name
+    "#{exported_from_service.name}"
+  end
+
+  private
+
+  def cannot_mount_self
+    if mounted_on_service_id.present? &&
+      exported_from_service_id.present? &&
+      mounted_on_service_id == exported_from_service_id
+
+      errors.add(:base, "can't mount self")
+    end
+  end
+end
diff --git a/db/migrate/20140929181001_create_shared_volumes.rb b/db/migrate/20140929181001_create_shared_volumes.rb
new file mode 100644
index 0000000..279a03c
--- /dev/null
+++ b/db/migrate/20140929181001_create_shared_volumes.rb
@@ -0,0 +1,12 @@
+class CreateSharedVolumes < ActiveRecord::Migration
+  def change
+    create_table :shared_volumes do |t|
+      t.references :exported_from_service, index: true
+      t.references :mounted_on_service, index: true
+
+      t.timestamps
+    end
+
+    add_index :shared_volumes, [:exported_from_service_id, :mounted_on_service_id], unique: true, name: 'index_shared_volume_keys'
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 6c63802..4923b3e 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20140919202446) do
+ActiveRecord::Schema.define(version: 20140929181001) do
 
   create_table "app_categories", force: true do |t|
     t.string   "name"
@@ -98,6 +98,17 @@
   add_index "services", ["app_id"], name: "index_services_on_app_id"
   add_index "services", ["name"], name: "index_services_on_name"
 
+  create_table "shared_volumes", force: true do |t|
+    t.integer  "exported_from_service_id"
+    t.integer  "mounted_on_service_id"
+    t.datetime "created_at"
+    t.datetime "updated_at"
+  end
+
+  add_index "shared_volumes", ["exported_from_service_id", "mounted_on_service_id"], name: "index_shared_volume_keys", unique: true
+  add_index "shared_volumes", ["exported_from_service_id"], name: "index_shared_volumes_on_exported_from_service_id"
+  add_index "shared_volumes", ["mounted_on_service_id"], name: "index_shared_volumes_on_mounted_on_service_id"
+
   create_table "template_repos", force: true do |t|
     t.string   "name"
     t.datetime "created_at"
diff --git a/spec/models/service_spec.rb b/spec/models/service_spec.rb
index 59836c3..a9fccd5 100644
--- a/spec/models/service_spec.rb
+++ b/spec/models/service_spec.rb
@@ -180,7 +180,7 @@
         double(:image_status,
                info: {
                  'Config' => {
-                   'ExposedPorts' => {'3000/tcp' => {} }
+                   'ExposedPorts' => { '3000/tcp' => {} }
                  }
                })
       end
@@ -280,6 +280,33 @@
       end
     end
 
+    context 'when volumes_from are not provided' do
+      it 'updates with an empty volumes_from list' do
+        expect(subject).to receive(:update).with(hash_including(volumes_from: []))
+        subject.update_with_relationships(attrs)
+      end
+
+    end
+
+    context 'when volumes_from are provided' do
+      let(:attrs_with_volumes_from) do
+        attrs.merge(
+            volumes_from: [{ service_id: 1 }]
+        )
+      end
+
+      let(:shared_volume) { SharedVolume.new(exported_from_service_id: 1) }
+
+      before do
+        subject.stub_chain(:volumes_from, :find_or_initialize_by).and_return(shared_volume)
+      end
+
+      it 'populates the related shared volumes' do
+        expect(subject).to receive(:update).with(hash_including(volumes_from: [shared_volume]))
+        subject.update_with_relationships(attrs_with_volumes_from)
+      end
+    end
+
     context 'when ports are not provided' do
       it 'updates with an empty ports list' do
         expect(subject).to receive(:update).with(hash_including(ports: []))
diff --git a/spec/models/shared_volume_spec.rb b/spec/models/shared_volume_spec.rb
new file mode 100644
index 0000000..1bacd7c
--- /dev/null
+++ b/spec/models/shared_volume_spec.rb
@@ -0,0 +1,51 @@
+require 'spec_helper'
+
+describe SharedVolume do
+  it { should belong_to(:exported_from_service) }
+
+  describe 'validations' do
+
+    it { should validate_presence_of :exported_from_service }
+
+    describe 'uniqueness validations' do
+      before do
+        # we need a record in the DB for the uniqueness validations to work
+        vol_from = Service.create!(name: 'vol_from')
+        mounted_on = Service.create!(name: 'mounted_on')
+        SharedVolume.create!(
+            exported_from_service: vol_from,
+            mounted_on_service_id: mounted_on.id
+        )
+      end
+
+      it { should validate_uniqueness_of(:exported_from_service).scoped_to(:mounted_on_service_id) }
+    end
+
+    describe 'mounting self' do
+
+      it 'errors when volume from and mounted on service ids match' do
+        subject.exported_from_service_id = 3
+        subject.mounted_on_service_id = 3
+        expect(subject.valid?).to be_false
+        expect(subject.errors[:base]).to include "can't mount self"
+      end
+
+      it 'does not error if one of the ids is nil' do
+        subject.exported_from_service = Service.new
+        expect(subject.valid?).to be_true
+      end
+    end
+  end
+
+  describe '#exported_from_service_name' do
+    let(:exported_from_service) { Service.new(name: 'my_service') }
+
+    before do
+      subject.exported_from_service = exported_from_service
+    end
+
+    it 'returns the volumes_from service name ' do
+      expect(subject.exported_from_service_name).to eql 'my_service'
+    end
+  end
+end
diff --git a/spec/support/shared/docker_runnable_example.rb b/spec/support/shared/docker_runnable_example.rb
index 6c7c0a0..d91485f 100644
--- a/spec/support/shared/docker_runnable_example.rb
+++ b/spec/support/shared/docker_runnable_example.rb
@@ -35,7 +35,7 @@
         model.ports = [{
           'host_interface' => '0.0.0.0',
           'host_port' => '8000',
-          'container_port' => '3000',
+          'container_port' => '3000'
         }]
       end
 
@@ -48,10 +48,10 @@
 
         before do
           model.ports = [{
-                           'host_interface' => nil,
-                           'host_port' => '',
-                           'container_port' => '3000',
-                         }]
+            'host_interface' => nil,
+            'host_port' => '',
+            'container_port' => '3000'
+          }]
         end
 
         it 'does not include the colon affixed to the host port info' do
@@ -60,13 +60,12 @@
         end
       end
 
-
       context 'when the UDP protocol is specified' do
 
         before do
           model.ports = [{
             'container_port' => '3000',
-            'proto' => 'udp',
+            'proto' => 'udp'
           }]
         end
 
@@ -81,7 +80,7 @@
         before do
           model.ports = [{
             'container_port' => '3000',
-            'proto' => 'tcp',
+            'proto' => 'tcp'
           }]
         end
 
@@ -145,6 +144,21 @@
         expect(model.docker_run_string).to include expected
       end
     end
+
+    context 'when volumes_from flags are specified' do
+
+      before do
+        exported_from_service = Service.new(name: 'foobar')
+        vol_from = SharedVolume.new(exported_from_service: exported_from_service)
+        model.volumes_from << vol_from
+      end
+
+      it 'generates a docker command with --volumes-from' do
+        expected = '--volumes-from foobar'
+        expect(model.docker_run_string).to include expected
+      end
+    end
+
   end
 
   describe '#docker_status' do

From cf8c47ed56f94a0293c78ab9e55e2e97e1cd64ff Mon Sep 17 00:00:00 2001
From: Rupak Ganguly <rupakg@gmail.com>
Date: Mon, 29 Sep 2014 15:12:33 -0400
Subject: [PATCH 2/5] Add serializers for service and shared_volume.

---
 app/serializers/service_serializer.rb         |  2 ++
 app/serializers/shared_volume_serializer.rb   | 14 +++++++++++++
 spec/serializers/service_serializer_spec.rb   |  3 ++-
 .../shared_volume_serializer_spec.rb          | 20 +++++++++++++++++++
 4 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 app/serializers/shared_volume_serializer.rb
 create mode 100644 spec/serializers/shared_volume_serializer_spec.rb

diff --git a/app/serializers/service_serializer.rb b/app/serializers/service_serializer.rb
index 2eba954..e196d38 100644
--- a/app/serializers/service_serializer.rb
+++ b/app/serializers/service_serializer.rb
@@ -11,6 +11,8 @@ class ServiceSerializer < ActiveModel::Serializer
 
   has_many :links, serializer: ServiceLinkSerializer
 
+  has_many :volumes_from, serializer: SharedVolumeSerializer
+
   def load_state
     service_state[:load_state]
   end
diff --git a/app/serializers/shared_volume_serializer.rb b/app/serializers/shared_volume_serializer.rb
new file mode 100644
index 0000000..cca027c
--- /dev/null
+++ b/app/serializers/shared_volume_serializer.rb
@@ -0,0 +1,14 @@
+class SharedVolumeSerializer < ActiveModel::Serializer
+  self.root = false
+
+  attributes :service_id, :service_name, :errors
+
+  def service_id
+    object.exported_from_service.id
+  end
+
+  def service_name
+    object.exported_from_service.name
+  end
+
+end
diff --git a/spec/serializers/service_serializer_spec.rb b/spec/serializers/service_serializer_spec.rb
index 6273239..2534ba2 100644
--- a/spec/serializers/service_serializer_spec.rb
+++ b/spec/serializers/service_serializer_spec.rb
@@ -8,7 +8,7 @@
     double(:image_status,
       info: {
         'Config' => {
-          'ExposedPorts' => {'3000/tcp' => {} }
+          'ExposedPorts' => { '3000/tcp' => {} }
         }
       })
   end
@@ -29,6 +29,7 @@
       :ports,
       :expose,
       :volumes,
+      :volumes_from,
       :command,
       :app,
       :categories,
diff --git a/spec/serializers/shared_volume_serializer_spec.rb b/spec/serializers/shared_volume_serializer_spec.rb
new file mode 100644
index 0000000..f1d5bd9
--- /dev/null
+++ b/spec/serializers/shared_volume_serializer_spec.rb
@@ -0,0 +1,20 @@
+require 'spec_helper'
+
+describe SharedVolumeSerializer do
+  let(:service) { Service.new }
+  let(:shared_volume_model) { SharedVolume.new }
+
+  before do
+    shared_volume_model.exported_from_service = service
+  end
+
+  it 'exposes the attributes to be jsonified' do
+    serialized = described_class.new(shared_volume_model).as_json
+    expected_keys = [
+      :service_id,
+      :service_name,
+      :errors
+    ]
+    expect(serialized.keys).to match_array expected_keys
+  end
+end

From efcdae549cbf32042d3d389d6368926e425f08a7 Mon Sep 17 00:00:00 2001
From: Rupak Ganguly <rupakg@gmail.com>
Date: Tue, 30 Sep 2014 09:56:52 -0400
Subject: [PATCH 3/5] Add volumes_from attribute to image and update service
 converter.

---
 app/models/converters/service_converter.rb    |  5 ++
 app/models/image.rb                           |  2 +
 app/serializers/image_serializer.rb           |  3 +-
 .../shared_volume_service_exists_validator.rb | 14 ++++++
 ...140929193656_add_volumes_from_to_images.rb |  5 ++
 db/schema.rb                                  |  3 +-
 .../converters/service_converter_spec.rb      | 11 ++++
 spec/serializers/image_serializer_spec.rb     |  1 +
 ...ed_volume_service_exists_validator_spec.rb | 50 +++++++++++++++++++
 9 files changed, 92 insertions(+), 2 deletions(-)
 create mode 100644 app/validators/shared_volume_service_exists_validator.rb
 create mode 100644 db/migrate/20140929193656_add_volumes_from_to_images.rb
 create mode 100644 spec/validators/shared_volume_service_exists_validator_spec.rb

diff --git a/app/models/converters/service_converter.rb b/app/models/converters/service_converter.rb
index d1dd5f2..f78206c 100644
--- a/app/models/converters/service_converter.rb
+++ b/app/models/converters/service_converter.rb
@@ -18,6 +18,7 @@ def to_image
         expose: service.expose,
         environment: service.environment,
         volumes: service.volumes,
+        volumes_from: service_volumes_from,
         command: service.command,
         type: service.type
       )
@@ -33,5 +34,9 @@ def service_links
       service.links.map { |link| { 'service' => link.linked_to_service.name, 'alias' => link.alias } }
     end
 
+    def service_volumes_from
+      service.volumes_from.map { |shared_vol| { 'service' => shared_vol.exported_from_service.name } }
+    end
+
   end
 end
diff --git a/app/models/image.rb b/app/models/image.rb
index 05ea3c3..fd75872 100644
--- a/app/models/image.rb
+++ b/app/models/image.rb
@@ -9,6 +9,7 @@ class Image < ActiveRecord::Base
   serialize :expose, Array
   serialize :environment, Array
   serialize :volumes, Array
+  serialize :volumes_from, Array
 
   belongs_to :template
 
@@ -17,4 +18,5 @@ class Image < ActiveRecord::Base
   validates :ports, has_container_ports: true, has_unique_ports: true
   validates :links, has_link_alias: true, service_link_exists: true
   validates :volumes, has_container_paths: true
+  validates :volumes_from, shared_volume_service_exists: true
 end
diff --git a/app/serializers/image_serializer.rb b/app/serializers/image_serializer.rb
index 517bb33..ba7b7f1 100644
--- a/app/serializers/image_serializer.rb
+++ b/app/serializers/image_serializer.rb
@@ -1,7 +1,8 @@
 class ImageSerializer < ActiveModel::Serializer
   self.root = false
 
-  attributes :id, :category, :name, :source, :description, :type, :expose, :ports, :links, :environment, :volumes, :command
+  attributes :id, :category, :name, :source, :description, :type, :expose,
+    :ports, :links, :environment, :volumes, :volumes_from, :command
 
   def category
     object.categories.first unless object.categories.blank?
diff --git a/app/validators/shared_volume_service_exists_validator.rb b/app/validators/shared_volume_service_exists_validator.rb
new file mode 100644
index 0000000..76643bf
--- /dev/null
+++ b/app/validators/shared_volume_service_exists_validator.rb
@@ -0,0 +1,14 @@
+class SharedVolumeServiceExistsValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    return unless value.present? && record.respond_to?(:template)
+    value.each do |shared_vol|
+      next if template_image_names_for(record).include? shared_vol['service']
+      record.errors[attribute] << 'service exporting shared volumes must exist'
+      break
+    end
+  end
+
+  def template_image_names_for(model)
+    model.template ? model.template.images.map(&:name) : []
+  end
+end
diff --git a/db/migrate/20140929193656_add_volumes_from_to_images.rb b/db/migrate/20140929193656_add_volumes_from_to_images.rb
new file mode 100644
index 0000000..45b5380
--- /dev/null
+++ b/db/migrate/20140929193656_add_volumes_from_to_images.rb
@@ -0,0 +1,5 @@
+class AddVolumesFromToImages < ActiveRecord::Migration
+  def change
+    add_column :images, :volumes_from, :text
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 4923b3e..7fdfc2d 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20140929181001) do
+ActiveRecord::Schema.define(version: 20140929193656) do
 
   create_table "app_categories", force: true do |t|
     t.string   "name"
@@ -52,6 +52,7 @@
     t.integer  "template_id"
     t.datetime "created_at"
     t.datetime "updated_at"
+    t.text     "volumes_from"
   end
 
   add_index "images", ["image_id"], name: "index_images_on_image_id", unique: true
diff --git a/spec/models/converters/service_converter_spec.rb b/spec/models/converters/service_converter_spec.rb
index 43ed467..5a09c9b 100644
--- a/spec/models/converters/service_converter_spec.rb
+++ b/spec/models/converters/service_converter_spec.rb
@@ -66,5 +66,16 @@
         service1.categories.build(app_category: app_categories(:category1))
       end
     end
+
+    context 'when handling services with volumes_from' do
+      before do
+        service1.volumes_from.create(exported_from_service: services(:service2))
+      end
+
+      it 'populates the image with volumes_from' do
+        expect(subject.to_image.volumes_from).to eql [{ 'service' => 'my-other-service' }]
+      end
+    end
+
   end
 end
diff --git a/spec/serializers/image_serializer_spec.rb b/spec/serializers/image_serializer_spec.rb
index 648f2d7..ba3e4e7 100644
--- a/spec/serializers/image_serializer_spec.rb
+++ b/spec/serializers/image_serializer_spec.rb
@@ -17,6 +17,7 @@
       :links,
       :environment,
       :volumes,
+      :volumes_from,
       :command
     ]
     expect(serialized.keys).to match_array expected_keys
diff --git a/spec/validators/shared_volume_service_exists_validator_spec.rb b/spec/validators/shared_volume_service_exists_validator_spec.rb
new file mode 100644
index 0000000..5bd436d
--- /dev/null
+++ b/spec/validators/shared_volume_service_exists_validator_spec.rb
@@ -0,0 +1,50 @@
+require 'spec_helper'
+
+describe SharedVolumeServiceExistsValidator do
+
+  let(:image_one) { Image.new(name: 'foo') }
+  let(:image_two) { Image.new(name: 'bar') }
+  let(:template) { Template.new(images: [image_one, image_two]) }
+  let(:record) { Image.new(template: template) }
+  let(:attribute) { 'volumes_from' }
+
+  subject { described_class.new(attributes: [attribute]) }
+
+  context 'when the attribute is valid' do
+
+    let(:value) do
+      [
+        { 'service' => 'foo' },
+        { 'service' => 'bar' }
+      ]
+    end
+
+    it 'returns no errors for volumes_from with existing services' do
+      subject.validate_each(record, attribute, value)
+      expect(record.errors).to be_empty
+    end
+
+  end
+
+  context 'when the attribute is not valid' do
+
+    let(:value) do
+      [
+        { 'service' => 'baz' },
+        { 'service' => 'quux' }
+      ]
+    end
+
+    it 'should set an error on the record' do
+      subject.validate_each(record, attribute, value)
+      expect(record.errors).to_not be_empty
+    end
+
+    it 'should quit validating after the first error is detected' do
+      subject.validate_each(record, attribute, value)
+      expect(record.errors[attribute].size).to eq 1
+    end
+
+  end
+
+end

From c9443dabe915db8f751a77efe386138398ac39f6 Mon Sep 17 00:00:00 2001
From: Rupak Ganguly <rupakg@gmail.com>
Date: Tue, 30 Sep 2014 13:21:53 -0400
Subject: [PATCH 4/5] Add volumes_from support to templates, template builder,
 serializer, and converters.

---
 app/builders/template_builder/from_fig.rb     |  7 +++++
 app/models/converters/template_converter.rb   | 15 +++++++++
 app/serializers/template_file_serializer.rb   |  1 +
 .../template_builder/from_fig_spec.rb         |  2 ++
 .../converters/template_converter_spec.rb     | 31 +++++++++++++++++++
 .../template_file_serializer_spec.rb          |  9 +++++-
 spec/support/fixtures/fig.yml                 |  2 ++
 spec/support/fixtures/wordpress.pmx           |  9 ++++--
 8 files changed, 73 insertions(+), 3 deletions(-)

diff --git a/app/builders/template_builder/from_fig.rb b/app/builders/template_builder/from_fig.rb
index 08483b4..d51e554 100644
--- a/app/builders/template_builder/from_fig.rb
+++ b/app/builders/template_builder/from_fig.rb
@@ -30,6 +30,7 @@ def image_from_fig_service(name, service_def)
         image.expose = service_def['expose']
         image.volumes = volumes(service_def['volumes'])
         image.environment = service_def['environment']
+        image.volumes_from = shared_volumes(service_def['volumes_from'])
       end
     end
 
@@ -54,5 +55,11 @@ def volumes(volumes_array)
       end
     end
 
+    def shared_volumes(vol_from_array)
+      Array(vol_from_array).map do |vol_from|
+        { 'service' => vol_from }
+      end
+    end
+
   end
 end
diff --git a/app/models/converters/template_converter.rb b/app/models/converters/template_converter.rb
index d986778..ab13755 100644
--- a/app/models/converters/template_converter.rb
+++ b/app/models/converters/template_converter.rb
@@ -20,6 +20,13 @@ def to_app
         linked_from_service.links = service_links_from_image(image)
       end
 
+      # Set-up shared volumes for services
+      template.images.each do |image|
+        next unless image.volumes_from?
+        the_service = find_service(image.name)
+        the_service.volumes_from = shared_volumes_from_image(image)
+      end
+
       App.new(
         name: template.name,
         from: "Template: #{template.name}",
@@ -62,6 +69,14 @@ def service_links_from_image(image)
       end
     end
 
+    def shared_volumes_from_image(image)
+      image.volumes_from.map do |vol_from|
+        SharedVolume.new(
+          exported_from_service: find_service(vol_from['service'])
+        )
+      end
+    end
+
     def find_service(name)
       services.find { |service| service.name == name }
     end
diff --git a/app/serializers/template_file_serializer.rb b/app/serializers/template_file_serializer.rb
index 47c6c57..ce2d1b9 100644
--- a/app/serializers/template_file_serializer.rb
+++ b/app/serializers/template_file_serializer.rb
@@ -11,6 +11,7 @@ class TemplateFileImageSerializer < ActiveModel::Serializer
       :links,
       :environment,
       :volumes,
+      :volumes_from,
       :command
 
     def category
diff --git a/spec/builders/template_builder/from_fig_spec.rb b/spec/builders/template_builder/from_fig_spec.rb
index 2233181..5fc8a1d 100644
--- a/spec/builders/template_builder/from_fig_spec.rb
+++ b/spec/builders/template_builder/from_fig_spec.rb
@@ -54,6 +54,8 @@
         expect(subject.images.find_by(name: 'db').volumes).to be_blank
         expect(subject.images.find_by(name: 'web').expose).to be_blank
         expect(subject.images.find_by(name: 'db').expose).to eq(['3306'])
+        expect(subject.images.find_by(name: 'web').volumes_from).to be_blank
+        expect(subject.images.find_by(name: 'db').volumes_from).to eq([{ 'service' => 'web' }])
       end
     end
 
diff --git a/spec/models/converters/template_converter_spec.rb b/spec/models/converters/template_converter_spec.rb
index ea1fd2e..972d6ea 100644
--- a/spec/models/converters/template_converter_spec.rb
+++ b/spec/models/converters/template_converter_spec.rb
@@ -27,6 +27,7 @@
           environment: { var: 'val' },
           command: '/boom shaka',
           volumes: ['volumes'],
+          volumes_from: ['service1'],
           type: 'mysql'
         )
       end
@@ -121,5 +122,35 @@
       end
     end
 
+    context 'with shared volumes' do
+
+      let(:image1) { Image.new(name: 'I1', source: 'I1:latest') }
+      let(:image2) { Image.new(name: 'I2', source: 'I2:latest') }
+
+      before do
+        image2.volumes_from = [{ 'service' => 'I1' }]
+        template.images = [image1, image2]
+      end
+
+      it 'creates a service for both images' do
+        app = subject.to_app
+        expect(app.services.size).to eq 2
+      end
+
+      it 'creates shared volumes where appropriate' do
+        app = subject.to_app
+        s1, s2 = app.services
+        expect(s1.volumes_from.size).to eq 0
+        expect(s2.volumes_from.size).to eq 1
+      end
+
+      it 'shared volumes linked to the services correctly' do
+        app = subject.to_app
+        s1, s2 = app.services
+        expect(s2.volumes_from.first.exported_from_service_id).to eq s2.id
+        expect(s2.volumes_from.first.mounted_on_service_id).to eq s1.id
+      end
+    end
+
   end
 end
diff --git a/spec/serializers/template_file_serializer_spec.rb b/spec/serializers/template_file_serializer_spec.rb
index d465219..785828f 100644
--- a/spec/serializers/template_file_serializer_spec.rb
+++ b/spec/serializers/template_file_serializer_spec.rb
@@ -33,7 +33,9 @@
             type: 'ghi',
             categories: ['jkl'],
             expose: [8000],
-            environment: [{ 'variable' => 'mno', 'value' => 'pqr' }]
+            environment: [{ 'variable' => 'mno', 'value' => 'pqr' }],
+            volumes: [{ 'host_path' => '/tmp/foo', 'container_path' => '/tmp/bar' }],
+            volumes_from: [{ 'service' => 'baz' }]
           )
         ]
       )
@@ -63,6 +65,11 @@
   environment:
   - variable: mno
     value: pqr
+  volumes:
+  - host_path: "/tmp/foo"
+    container_path: "/tmp/bar"
+  volumes_from:
+  - service: baz
       EXPECTED
     end
 
diff --git a/spec/support/fixtures/fig.yml b/spec/support/fixtures/fig.yml
index 191ec4b..d0c1675 100644
--- a/spec/support/fixtures/fig.yml
+++ b/spec/support/fixtures/fig.yml
@@ -18,3 +18,5 @@ db:
   environment:
     - variable: MYSQL_ROOT_PASSWORD
       value: mysecretpassword
+  volumes_from:
+    - web
diff --git a/spec/support/fixtures/wordpress.pmx b/spec/support/fixtures/wordpress.pmx
index 8385fe2..0e1d2db 100644
--- a/spec/support/fixtures/wordpress.pmx
+++ b/spec/support/fixtures/wordpress.pmx
@@ -24,7 +24,12 @@
         }
       ],
       "category": "DB Tier",
-      "type": "mysql"
+      "type": "mysql",
+      "volumes_from": [
+        {
+          "service": "WP"
+        }
+      ],
     },
     {
       "name": "WP",
@@ -50,7 +55,7 @@
         }
       ],
       "volumes": [
-      {
+        {
           "host_path": "cache/",
           "container_path": "/tmp/cache"
         }

From 8ececad01a65187411045c7937b1bf21e10a2c79 Mon Sep 17 00:00:00 2001
From: Rupak Ganguly <rupakg@gmail.com>
Date: Tue, 30 Sep 2014 15:02:08 -0400
Subject: [PATCH 5/5] Add support for volumes_from to the apps, templates and
 services controllers.

---
 app/controllers/apps_controller.rb            | 3 ++-
 app/controllers/services_controller.rb        | 1 +
 app/controllers/templates_controller.rb       | 4 ++--
 spec/controllers/templates_controller_spec.rb | 1 +
 4 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/app/controllers/apps_controller.rb b/app/controllers/apps_controller.rb
index 7d9209e..dfbdaca 100644
--- a/app/controllers/apps_controller.rb
+++ b/app/controllers/apps_controller.rb
@@ -77,7 +77,8 @@ def app_params
       environment: [[:variable, :value, :required]],
       ports: [[:host_interface, :host_port, :container_port, :proto]],
       expose: [],
-      volumes: [[:host_path, :container_path]]
+      volumes: [[:host_path, :container_path]],
+      volumes_from: [[:service]]
     )
   end
 
diff --git a/app/controllers/services_controller.rb b/app/controllers/services_controller.rb
index 65a72d6..1e13785 100644
--- a/app/controllers/services_controller.rb
+++ b/app/controllers/services_controller.rb
@@ -51,6 +51,7 @@ def service_params(extras=nil)
       ports: [[:host_interface, :host_port, :container_port, :proto]],
       expose: [],
       volumes: [[:host_path, :container_path]],
+      volumes_from: [[:service_id]],
       links: [[:service_id, :alias]],
       environment: [[:variable, :value, :required]]
     )
diff --git a/app/controllers/templates_controller.rb b/app/controllers/templates_controller.rb
index 1ddbe44..1cd7d5d 100644
--- a/app/controllers/templates_controller.rb
+++ b/app/controllers/templates_controller.rb
@@ -49,8 +49,8 @@ def template_create_params
         expose: [],
         links: [[:service_id, :alias]],
         environment: [[:variable, :value, :required]],
-        links: [[:service_id, :alias]],
-        ports: [[:host_interface, :host_port, :container_port, :proto]]
+        ports: [[:host_interface, :host_port, :container_port, :proto]],
+        volumes_from: [[:service_id]]
       ]]
     )
   end
diff --git a/spec/controllers/templates_controller_spec.rb b/spec/controllers/templates_controller_spec.rb
index edd2253..bd3e406 100644
--- a/spec/controllers/templates_controller_spec.rb
+++ b/spec/controllers/templates_controller_spec.rb
@@ -43,6 +43,7 @@
               { 'variable' => 'GIT_REPO', 'value' => 'https://github.com/fermayo/hello-world-php.git' }
             ],
             'volumes' =>  [],
+            'volumes_from' =>  [{ 'service_id' => '3' }],
             'command' => '/start web'
           }
         ]