Juju Charm Quality Guidelines -> Charm Features

[Jorge O. Castro]

We just had a session on improving what used to be called the Charm
Quality Guidelines, which really are charm features, so we went bullet
by bullet and reworded a bunch of them to make sense, and consolidated
the sections, here's what we came up with:

Proposed Bullets:

Data Handling:

Handles the service's user data
Provides backup mechanism
Provides a restore mechanism
Provides encryption

Secure:

Contains a well tested AppArmor profile
Doesn't run as root
Per instance or service access control
Defaults to secure communication


Reliable:

Fails gracefully if upstream source goes missing
Contains a suite of integration tests with the charm that pass
Configuration options have safe defaults


Scaleable:

Responds to add-unit based on the service's needs
Responds to remove-unit based on the service's needs
Reuses existing charms for supporting services


Upstream Friendly

Follow deployment recommendations from upstream best practices
Provide up to date versions of the upstream release


Flexible

Exposes version of service as a config option to allow easy upgrades
Adheres to the coding guidelines of the language your charm is written in
Exposed configurations are subsets of opinionated deployments
Allow installation from pure upstream source
Allow installation from your local source
Allow installation from PPA (if available)
Allow installation from the Ubuntu repository

Easy to Deploy (these will move to policy soon, so consider this a
temporary category)

README with examples of use for a typical workload
README with examples of use for workloads at scale
README with examples of use recommend best-practice relationships


-- 
Jorge Castro
Canonical Ltd.
http://juju.ubuntu.com/ - Automate your Cloud Infrastructure