DevStack is a set of scripts and utilities to quickly deploy an OpenStack cloud.

# Goals

* To quickly build dev OpenStack environments in a clean Oneiric or Precise environment
* To describe working configurations of OpenStack (which code branches work together?  what do config files look like for those branches?)
* To make it easier for developers to dive into OpenStack so that they can productively contribute without having to understand every part of the system at once
* To make it easy to prototype cross-project features
* To sanity-check OpenStack builds (used in gating commits to the primary repos)

Read more at http://devstack.org (built from the gh-pages branch)

IMPORTANT: Be sure to carefully read `stack.sh` and any other scripts you execute before you run them, as they install software and may alter your networking configuration.  We strongly recommend that you run `stack.sh` in a clean and disposable vm when you are first getting started.

# Devstack on Xenserver

If you would like to use Xenserver as the hypervisor, please refer to the instructions in `./tools/xen/README.md`.

# Versions

The devstack master branch generally points to trunk versions of OpenStack components.  For older, stable versions, look for branches named stable/[release] in the DevStack repo.  For example, you can do the following to create a diablo OpenStack cloud:

    git checkout stable/diablo
    ./stack.sh

You can also pick specific OpenStack project releases by setting the appropriate `*_BRANCH` variables in `localrc` (look in `stackrc` for the default set).  Usually just before a release there will be milestone-proposed branches that need to be tested::

    GLANCE_REPO=https://github.com/openstack/glance.git
    GLANCE_BRANCH=milestone-proposed

# Start A Dev Cloud

Installing in a dedicated disposable vm is safer than installing on your dev machine!  To start a dev cloud:

    ./stack.sh

When the script finishes executing, you should be able to access OpenStack endpoints, like so:

* Horizon: http://myhost/
* Keystone: http://myhost:5000/v2.0/

We also provide an environment file that you can use to interact with your cloud via CLI:

    # source openrc file to load your environment with osapi and ec2 creds
    . openrc
    # list instances
    nova list

If the EC2 API is your cup-o-tea, you can create credentials and use euca2ools:

    # source eucarc to generate EC2 credentials and set up the environment
    . eucarc
    # list instances using ec2 api
    euca-describe-instances

# Customizing

You can override environment variables used in `stack.sh` by creating file name `localrc`.  It is likely that you will need to do this to tweak your networking configuration should you need to access your cloud from a different host.

# Swift

Swift is not installed by default, you can enable easily by adding this to your `localrc`:

    ENABLED_SERVICE="$ENABLED_SERVICES,swift"

If you want a minimal Swift install with only Swift and Keystone you can have this instead in your `localrc`:

    ENABLED_SERVICES="key,mysql,swift"

If you use Swift with Keystone, Swift will authenticate against it. You will need to make sure to use the Keystone URL to auth against.

Swift will be acting as a S3 endpoint for Keystone so effectively replacing the `nova-objectstore`.

Only Swift proxy server is launched in the screen session all other services are started in background and managed by `swift-init` tool.

By default Swift will configure 3 replicas (and one spare) which could be IO intensive on a small vm, if you only want to do some quick testing of the API you can choose to only have one replica by customizing the variable `SWIFT_REPLICAS` in your `localrc`.