DOC-047: More container documentation.

Author: mvousden

docs/developer-notes.rst

@@ -11,8 +11,11 @@ http://docs.ansible.com/ansible/.
 
 .. _dev-build-process:
 
+Build and Run
+-------------
+
 The Build and Run Processes for Virtual Machines
-------------------------------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 This graph shows the operations involved in the build and run processes for
 :term:`virtual machine`\s.
@@ -38,29 +41,45 @@ break down the build process:
   administrators to atlas.hashicorp.com, where they become available to all
   Vagrant users.
 
+The Build and Run Processes for Containers
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In the same way, this graph shows the operations involved in the build and run
+processes for :term:`container`\s.
+
+.. image:: images/container_graph.png
+
+Again the process of creating and running a container as a user is as simple as
+following the instructions in :ref:`getting-started-user`. The build process is
+also similar; a container template (:term:`image`) is downloaded, a container
+is created and provisioned, and the container is packaged as an image for
+download by all Docker users. The key difference is that Docker pushes the
+image to https://hub.docker.com/ as opposed to Vagrant.
+
+Details
+~~~~~~~
+
 The build (make) process in step 3 in :ref:`getting-started-poweruser` allowed
 us to create a virtual environment. The Makefile in the software repository can
 build multiple targets. Each target runs Ansible on the ``master.yml``
-playbook, which in turn runs the ``create_vm`` role in the roles
-directory. This creates a virtual machine and provisions it with the playbook
-passed as a command-line argument in ``Makefile``, which lives in the jobs
-directory. It will also do some post-provisioning tasks using the hookbook,
-again passed as a command-line argument. The fundamental difference between the
-playbook and the hookbook is that the playbook is run on the guest virtual
-machine by :term:`Vagrant`, and the hookbook is run on the host
-machine. Different Makefile targets may place different build artefacts in the
-artefacts directory.
+playbook, which in turn runs the ``create_vm`` or ``create_container`` role in
+the roles directory. This creates a virtual machine or container and provisions
+it with the playbook passed as a command-line argument in ``Makefile``, which
+lives in the jobs directory. It will also do some post-provisioning tasks using
+the hookbook, again passed as a command-line argument. The fundamental
+difference between the playbook and the hookbook is that the playbook is run on
+the guest virtual machine by :term:`Vagrant`, and the hookbook is run on the
+host machine. Different Makefile targets may place different build artefacts in
+the artefacts directory.
 
 Roles add or configure software, playbooks describe the roles that must be
 enacted to provision the machine, hookbooks describe what to do with that
 machine (like creating a :term:`box file`), and jobs are Makefile targets that
-produce certain machines.
-
-To add a new environment, one needs to add a job that follows the pattern of
-existing jobs.
+produce certain machines. To add a new environment, one needs to add a job that
+follows the pattern of existing jobs.
 
 Where Things Are
-----------------
+~~~~~~~~~~~~~~~~
 
 In order to add jobs, one should edit ``Makefile``. In order to do that, one
 would need to know where things are, hence the purpose of this section. The
@@ -249,9 +268,10 @@ Summary and Final Words
 To summarise, :term:`virtual environment`\s are created from an empty Ubuntu
 virtual machine after being provisioned and packaged. This build process allows
 the user to create a Virtual Micromagnetics :term:`virtual machine` using
-Vagrant and VirtualBox. We have also presented how a new environment can be
-created, how the software of that environment can be controlled, and how the
-virtual machines can be parameterised.
+Vagrant and VirtualBox. A similar approach is used to create :term:`image`\s
+for :term:`Docker` :term:`containers`\. We have also presented how a new
+environment can be created, how the software of that environment can be
+controlled, and how the virtual machines can be parameterised.
 
 Thank you for using Virtual Micromagnetics! If you create roles for your
 favourite software, consider sharing them with the community. You can create a