* 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
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.
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:
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::
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 is enabled by default configured with only one replica to avoid being IO/memory intensive on a small vm. When running with only one replica the account, container and object services will run directly in screen. The others services like replicator, updaters or auditor runs in background.
enable_service key mysql s-proxy s-object s-container s-account
If you only want to do some testing of a real normal swift cluster with multiple replicas you can do so by customizing the variable `SWIFT_REPLICAS` in your `localrc` (usually to 3).
If you are enabling `swift3` in `ENABLED_SERVICES` devstack will install the swift3 middleware emulation. Swift will be configured to act as a S3 endpoint for Keystone so effectively replacing the `nova-objectstore`.
devstack supports adding specific Quantum configuration flags to both the Open vSwitch and LinuxBridge plugin configuration files. To make use of this feature, the following variables are defined and can be configured in your `localrc` file:
A more interesting setup involves running multiple compute nodes, with Quantum networks connecting VMs on different compute nodes.
You should run at least one "controller node", which should have a `stackrc` that includes at least:
disable_service n-net
enable_service q-svc
enable_service q-agt
enable_service q-dhcp
enable_service q-l3
enable_service q-meta
enable_service quantum
You likely want to change your `localrc` to run a scheduler that will balance VMs across hosts:
SCHEDULER=nova.scheduler.simple.SimpleScheduler
You can then run many compute nodes, each of which should have a `stackrc` which includes the following, with the IP address of the above controller node: