TripleO Zero Footprint Installer

https://blueprints.launchpad.net/tripleo/+spec/zero-footprint

This spec introduces support for an installer mode which has zero (or at least much less) dependencies than we do today. It is meant to be an iteration of the Undercloud and All-In-One (standalone) installers that allows you to end up with the same result without having to install all of the TripleO dependencies on your host machine.

Problem Description

Installing python-tripleoclient on a host machine currently installs a lot of dependencies many of which may be optional for smaller standalone type installations. Users of smaller standalone installations can have a hard time understanding the differences between what TripleO dependencies get installed vs which services TripleO installs.

Additionally, some developers would like a fast-track way to develop and run playbooks without requiring local installation of an Undercloud which in many cases is done inside a virtual machine to encapsulate the dependencies that get installed.

Proposed Change

A new zero footprint installer can help drive OpenStack Tripleoclient commands running within a container. Using this approach you can:

  1. Generate Ansible playbooks from a set of Heat templates (tripleo-heat-templates), Heat environments, and Heat parameters exactly like we do today using a Container. No local dependencies would be required to generate the playbooks.
  2. (optionally) Execute the playbooks locally on the host machine. This would require some Ansible modules to be installed that TripleO depends on but is a much smaller footprint than what we require elsewhere today.

Alternatives

Create a subpackage of python-tripleoclient which installs less dependencies. The general footprint of required packages would still be quite high (lots of OpenStack packages will still be installed for the client tooling).

Or do nothing and continue to use VMs to encapsulate the dependencies for an Undercloud/All-In-One installer and generate Ansible playbooks. Setting up a local VM requires more initial setup and dependencies however and is heavier than just using a local container to generate the same playbooks.

Security Impact

As a container will be used to generate Ansible playbooks the user may need to expose some local data/files to the installer container. This is likely a minimal concern as we already require this data to be exposed to the Undercloud and All-In-One installers.

Other End User Impact

None

Performance Impact

Faster deployment and testing of local All-On-One setups.

Other Deployer Impact

None

Developer Impact

Faster deployment and testing of local All-On-One setups.

Implementation

Assignee(s)

Primary assignee:
dprince

Work Items

  • A new ‘tripleoclient’ container
  • New project to drive the installation (Talon?)
  • Continue to work on refining the Ansible playbook modules to provide a cleaner set of playbook dependencies. Specifically those that depend on the any of the traditional TripleO/Heat agent hooks and scripts.
  • documentation updates

Dependencies

None.

Testing

This new installer can likely suppliment or replace some of the testing we are doing for All-In-One (standalone) deployments in upstream CI.

Documentation Impact

Docs will need to be updated.

References

None