openstack/training-guides
Code Issues Proposed changes
training-guides/doc/upstream-training/source/slides/code-devstack.rst
Ian Y. Choi ccac650f41 [upstream] systemd instead of screen for DevStack 
This updates the code-devstack slides to explain how
to use systemd instead of screen.  It notes that sceen
is now deprecated.  The exercise has been updated to
use systemd instead of screen.

Change-Id: Ie63249c98044b90bd64aa19a730792f26a2f7e3f
Co-Authored-By: Mars Toktonaliev <mars.toktonaliev@nokia.com>
Co-Authored-By: Jay S. Bryant <jsbryant@electronicjungle.net>
2017-05-04 22:11:58 -04:00

3.2 KiB
Raw Blame History

Demo environment

image

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: http://docs.openstack.org/developer/devstack/

DevStack Clone and Setup

  • Clone DevStack to your vm
git clone https://git.openstack.org/openstack-dev/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

image

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

image

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 commands like cinder or nova to interact with the services running on your VM