Openstack in 20 minutes

Openstack for the lazy

If you are like me, you do a lot of testing.  I have built and rebuilt Openstack single (all in one) and multi-node installations hundreds of times. With Devstack, you have the ability of creating an Openstack single node instance within minutes. While the default settings should suffice for most, I'll add some additional details that may help with all of the testing you wish to accomplish.

The 'server'

It's best to start with a dedicated system (laptop, desktop, or server) but this can be accomplished with a virtual machine (KVM, VirtualBox, VMFusion, etc). If going with a virtual machine, provision your server with at least 1GB of memory 4GB of virtual hard drive space and 1 CPU core. Install Ubuntu (12.04 LTS or 14.04 LTS). The step by step is fairly easy and shouldn't take more than a few minutes. The default user account will be setup with sudo access.

Download/install dependencies and Devstack

Create an Openstack user account and install Git:

sudo su - 
adduser stack 
echo "stack ALL=(ALL) NOPASSWD: ALL" » /etc/sudoers 
su stack 
sudo apt-get install git -y 
git clone 
cd devstack

Openstack user account

Devstack will complain if you try to run it as root, so if you didn't create a user account 'stack' it will prompt you to create one:

$ sudo ./ You are running this script as root. Cut it out. Really. If you need an account to run DevStack, do this (as root, heh) to create stack: /opt/devstack/tools/

Create a configuration file for Devstack

Although you can run the Devstack install script with the default parameters, I'd recommend creating a local configuration file to determine a few components. Those familiar with Openstack will know that each service requires a specific configuration file (Keystone, Cinder, etc). You can create a master file that Devstack uses to build all of the configuration files for you called local.conf. Here is a sample:

FLAT_INTERFACE=eth0 LOGFILE=/opt/devstack/ 
Q_FLOATING_ALLOCATION_POOL=start=,end= PUBLIC_NETWORK_GATEWAY= ADMIN_PASSWORD=mydevstackpassword MYSQL_PASSWORD=mydevstackpassword RABBIT_PASSWORD=mydevstackpassword SERVICE_PASSWORD=mydevstackpassword SERVICE_TOKEN=mydevstackpassword 
disable_service rabbit 
enable_service qpid 
enable_service quantum 
enable_service n-cpu 
enable_service n-cond 
disable_service n-net 
enable_service q-svc 
enable_service q-dhcp 
enable_service q-l3 
enable_service q-meta 
enable_service quantum 
enable_service tempest

Here is what each one means:

  • FLOATING_RANGE - A range of IP's not in use on your local network. In the example above I use for various machines and have reserved the upper block for testing.
  • FIXED_RANGE - This is the internal range that VM's pull from. If you keep this value the same across multiple deployments then you can leverage overlay technologies such as VXLAN.
  • FIXEDNETWORKSIZE - The maximum amount of hosts allowed within the FIXED_RANGE.
  • FLAT_INTERFACE - Indicates the network interface card that devstack will use for network access. I assume you are using eth0 but it depends on your environment.
  • LOGFILE - Self explanatory.
  • QFLOATINGALLOCATION_POOL - This value lets you explicitly set the pool of IPs used for this Devstack instance.
  • PUBLICNETWORKGATEWAY - Self explanatory

Most of the services listed will be enabled but this also ensures you are using Neutron networking and keeping Nova networking (deprecated) disabled. I'll give more examples in future blog posts regarding OVS and ML2.

Optional - enable Icehouse branch

Use the following to checkout the latest Openstack branch - Icehouse:

git checkout stable/icehouse

Setup physical host network environment

The following commands will ensure network traffic will be correctly routed in and out of the Devstack VMs:

echo 1 > /proc/sys/net/ipv4/ip_forward 
echo 1 > /proc/sys/net/ipv4/conf/eth0/proxy_arp 
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

The ipforward and proxyarp changes will be reset when the machice reboots. You can make these changes permanent by editing /etc/sysctl.conf and adding the following lines:

net.ipv4.conf.eth0.proxy_arp = 1 net.ipv4.ip_forward = 1

Run ./ and grab some popcorn

No really....grab some popcorn. The stack script will install MySQL, RabbitMQ, additional binaries and dependencies. This can take anywhere from 10-20 minutes. Once completed, point your browser to http://hostip and log in with the admin credentials listed above.

Upload image

Once logged in, you'll need some images to start. On the dashboard -> go to Admin Tab → Images → Create Image. Name the image whatever you want and set the location to where ever your image is located. You can use the following to get you started:

CirrOS 0.3.2

Ubuntu Precise

Set the image format to QCOW2, and click ‘Create Image’. Devstack will pull the image, convert it and make it available for VM use. Wash, rinse and repeat

When you are done, run the following commands to shutdown, clean up files (if you want to start from scratch, and to rejoin after a reboot:

Shutdown devstack: ./

Remove files that Devstack installed: ./

Rejoin Devstack after reboot: ./


Devstack is a simple, yet powerful way of testing Openstack and various SDN components. With minimal resources, and defined configuration files, one can setup a virtual environment for testing without the hassle of breaking production equipment. Until next time...