[Engineering] Migrating to Scap from Trebuchet, Timelines and Such

Tue Apr 5 17:14:19 UTC 2016

The Release Engineering team's goal for the April-June 2016 quarter is
to move everything that is currently deployed with Trebuchet over to
Scap. With the release of Scap 3.1.0, everything that is deployed via
Trebuchet can be ported to Scap—it supports git-fat, restarting
services, and there is even a puppet provider.

== What is the timeline? ==

We have made tasks for all of the existing projects that are deployed
via Trebuchet[0], and the goal is to move these all by **2016-06-30**
(AKA the End of The Quarter™).

If we missed your project that is deployed via Trebuchet, please add a
task with the #scap3 tag in phabricator.

== What is Scap? Why are we moving to it? ==

Scap is a tool that the Release Engineering team has been working on
as a successor to the salt-based Trebuchet deployment system.

* Stable and secure SSH-based command and control
* Detailed error logs available from every target node
* Built on tools that everyone is familiar with—SSH and Git

== What does it mean to move to Scap? ==

To assist with the move from Trebuchet to Scap:
* We have written documentation, including a quick start setup guide [1]
* Release Engineering folks are available to help with migrations,
questions, concerns in the #scap3 channel on freenode

== Why isn't Release Engineering just porting everything all by their
lonesome? ==

We're hoping that by the end of the quarter, not only will we get all
projects migrated, but we also want folks to be familiar with Scap and
know how to troubleshoot their own deployments. In the end, the goal
is to scale knowledge of how to use Wikimedia's deployment tooling to
the wider organization instead of a handful of people. "Teach a person
to fish"[2] and all...

<3,
Tyler Cipriani
WMF Release Engingeering

[0] https://phabricator.wikimedia.org/project/view/1824/
[1] https://doc.wikimedia.org/mw-tools-scap/scap3/quickstart/setup.html
[2] https://en.wiktionary.org/wiki/give_a_man_a_fish_and_you_feed_him_for_a_day;_teach_a_man_to_fish_and_you_feed_him_for_a_lifetime