Demo environment

_images/os_background.png

DevStack

A bunch of scripts to build a full OpenStack environment
Used as
- Demo environment
- Part of the OpenStack project’s functional testing
Single and multi node setup
Installs services from source
- from git master by default
- from stable branches by configuration, e.g. stable/newton
Documentation: https://docs.openstack.org/devstack/

DevStack Clone and Setup

Clone DevStack to your vm

git clone https://opendev.org/openstack/devstack

Make any local configurations changes (set passwords, IP addresses, etc.)

cd ./devstack
cp ./samples/local.conf .
nano ./local.conf

Note

Students can use a different editor instead of nano with their own preferences (e.g. vi, emacs, or whatever they want).

Run DevStack

./stack.sh

Note

DevStack should already be installed in the VM image you downloaded. These instructions are provided for future reference in the case that students need to start from scratch.

http://localhost/

After DevStack is run Horizon is accessible via localhost

_images/devstack-http-localhost.png

Running services in DevStack

screen command was used to access the virtual terminals running the installed services
- screen use is now deprecated
- To use screen explicitly set USE_SCREEN=True option in local.conf
More details: Developing with Devstack

_images/devstack-screen.png

Note

Screen is going away in Queens : http://lists.openstack.org/pipermail/openstack-dev/2017-May/116301.html
Useful screen commands:
- List sessions: screen -ls
- Connect: screen -R <session name>
- Start a new session: screen -C devstack/stack-screenrc
- Move between services: <ctrl>-a n , <ctrl>-a p
- Kill and restart a service: <ctrl>-c , <up arrow> to retrieve command
- Disconnect: <ctrl>-a d

DevStack services with Systemd

systemd is the replacement for screen
Services in DevStack are running as systemd units named devstack@$servicename.service
Interact with services using commands like sudo systemctl <start|stop|restart> devstack@$servicename.service
Follow logs with journalctl -f --unit devstack@$servicename.service
More details: Using Systemd in DevStack

Exercise

Ensure you have the DevStack repository cloned to the VM where you would like to use it
Use systemctl status devstack@* to ensure devstack is running on your VM. If it is not started, start it with systemctl start devstack@*
Use the journalctl command to view output from your favorite service
Ensure you can use the openstack command to interact with the services running on your VM