BOSH

The BOSH (or "BOSH outer shell") tool handles building, deployment, configuring, and management of software. It's best described as an "orchestration" tool perhaps.

It is developed as part of the Cloud Foundry project. Cloud Foundry is a platform-as-a-service system which we would be interested in being able to deploy with Baserock. Cloud Foundry initially used Chef for orchestration, but later developed BOSH to replace it.

BOSH and Baserock

BOSH does some building of software, but also requires a prebuilt base operating system image (called a stemcell). Baserock provides systems built entirely from source, and also provides a way of describing deployments, but the Baserock deployment tooling is very minimal and doesn't provide any ongoing monitoring functionality of its own. Due to this overlap of functionality, it's tricky to work out how to use Baserock with BOSH in a way that brings out the advantages of both.

Early steps towards this:

• creating a Baserock 'stemcell' for use with BOSH
• writing a white paper comparing different aspects of the tools.

Understanding BOSH

This may be a bit of a dumping ground for now.

Bosh bootstrapping / development tools

Micro BOSH

This isn't an alternative implementation at all, it's just a name used to describe a fully working BOSH instance that runs in a single virtual machine.

BOSH itself is a set of VMs that needs to be deployed and managed with BOSH, and thus there needs to be some way of bootstrapping an instance of BOSH. This is done with the bosh micro command, implemented by a plugin for the bosh commandline interface called bosh_cli_plugin_micro.

Deployment of a 'Micro BOSH' instance using the bosh micro command is automated further by the bosh-bootstrap plugin, which automates the process of setting up a 'Micro BOSH' instance in either an OpenStack cloud, a vSphere cloud, or Amazon Web Services.

See also: https://github.com/drnic/bosh-getting-started/blob/master/create-a-bosh/creating-a-micro-bosh-from-stemcell-openstack.md

BOSH Lite

BOSH Lite isn't an alternative implementation of BOSH either. It's a tool for developers who are working on BOSH itself. It makes use of Vagrant, which is a general-purpose tool for creating and managing a development environment inside a virtual machines. Vagrant supports several virtualisation platforms, of these BOSH-Lite can work with VirtualBox, VMware and Amazon Web Services.

Vagrant requires a prebuilt operating system image, known as a base box. BOSH-Lite provides custom baseboxes, which are built using the Packer tool. For example, the VirtualBox basebox is built by running the bin/build-virtualbox BASH script, which causes Packer to build a base box on top of an Ubuntu 14.04 x86_64 image following this template. As part of this it runs the packer-bosh Packer provisioning plugin, which I can't really work out what it does right now. The Vagrantfile supplied by BOSH-Lite tells Vagrant to download a prebuilt basebox from https://atlas.hashicorp.com/ named cloudfoundry/boshlite. This basebox is built by a job in the Concourse CI system, defined in bosh-lite.git.

Alternative BOSH implementations

The canonical BOSH codebase is Cloud Foundry BOSH. However, it seems its input format is well-defined enough that at least one alternative implementation of BOSH is maintained as well.

Nice BOSH

Nise BOSH is a reimplementation of BOSH, in just over 1000 lines of Ruby code. (The canonical BOSH implementation is over 120,000 lines of Ruby code). Presumably it lacks some features compared to the main implementation.

BOSH Solo

BOSH Solo is an obsolete tool that seems like it would execute BOSH releases outside of a full BOSH environment.