watcher-specs/README.rst

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README
=======

Watcher Specifications
======================


This git repository is used to hold approved design specifications for
additions to the Watcher project.  Reviews of the specs are done in gerrit,
using a similar workflow to how we review and merge changes to the code itself.
For specific policies around specification review, refer to the end of this
document.

The layout of this repository is::

  specs/<release>/

Where there are two sub-directories:

  specs/<release>/approved: specifications approved, but not yet implemented
  specs/<release>/implemented: implemented specifications

The lifecycle of a specification
--------------------------------

Developers proposing a specification should propose a new file in the
``approved`` directory. watcher-specs-core will review the change in the usual
manner for the OpenStack project and eventually it will get merged if a
consensus is reached. At this time the Launchpad blueprint is also approved.
The developer is then free to propose code reviews to implement their
specification. These reviews should be sure to reference the Launchpad
blueprint in their commit message for tracking purposes.

Once all code for the feature is merged into Watcher, the Launchpad blueprint
is marked complete. As the developer of an approved specification, it is your
responsibility to mark your blueprint complete when all of the required
patches have merged.

Periodically, someone from watcher-specs-core will move implemented
specifications from the ``approved`` directory to the ``implemented``
directory. Whilst individual developers are welcome to propose this move for
their implemented specifications, we have generally just done this in a batch
at the end of the release cycle. It is important to create redirects when this
is done so that existing links to the approved specification are not broken.
Redirects aren't symbolic links, they are defined in a file which sphinx
consumes. An example is at ``specs/mitaka/redirects``.

This directory structure allows you to see what we thought about doing,
decided to do and actually got done. Users interested in functionality in a
given release should only refer to the ``implemented`` directory.

Example specifications
----------------------

You can find an example spec in ``specs/template.rst``.

Backlog specifications
----------------------

Additionally, we allow the proposal of specifications that do not have a
developer assigned to them. These are proposed for review in the same manner as
above, but are added to::

  specs/backlog/approved

Specifications in this directory indicate the original author has either
become unavailable or has indicated that they are not going to implement the
specification. The specifications found here are available as projects for
people looking to get involved with Watcher. If you are interested in
claiming a spec, start by posting a review for the specification that moves it
from this directory to the next active release. Please set yourself as the new
`primary assignee` and maintain the original author in the `other contributors`
list.

Working with gerrit and specification unit tests
------------------------------------------------

For more information about working with gerrit, see
http://docs.openstack.org/infra/manual/developers.html#development-workflow

To validate that the specification is syntactically correct (i.e. get more
confidence in the Jenkins result), please execute the following command::

  $ tox

After running ``tox``, the documentation will be available for viewing in HTML
format in the ``doc/build/`` directory.

Specification review policies
=============================

There are a number of review policies which watcher-specs-core will apply when
reviewing proposed specifications. They are:

Trivial specifications
----------------------

Proposed changes which are trivial (very small amounts of code) and don't
change any of our public APIs are sometimes not required to provide a
specification. In these cases a Launchpad blueprint is considered sufficient.
These proposals are approved during the `Open Discussion` portion of the
weekly Watcher IRC meeting. If you think your proposed feature is trivial and
meets these requirements, we recommend you bring it up for discussion there
before writing a full specification.

Previously approved specifications
----------------------------------

`Specifications are only approved for a single release`. If your specification
was previously approved but not implemented (or not completely implemented),
then you must seek re-approval for the specification. You can re-propose your
specification by doing the following:

* Copy (not move) your specification to the right directory for the current
  release.
* Update the document to comply with the new template.
* If there are no functional changes to the specification (only template
  changes) then add the `Previously-approved: <release>` tag to your commit
  message.
* Send for review.
* watcher-specs-core will merge specifications which meet these requirements
  with a single +2.

Specifications which depend on merging code in other OpenStack projects
-----------------------------------------------------------------------

For specifications `that depend on code in other OpenStack projects merging`
we will not approve the Watcher specification until the code in that other
project has merged. To indicate your specification is in this state, please
use the Depends-On git commit message tag. The correct format is
`Depends-On: <change id of other work>`. watcher-specs-core can approve the
specification at any time, but it won't merge until the code we need to land
in the other project has merged as well.