en/glep/glep-0042.txt

GLEP: 42
Title: Critical News Reporting
Version: $Revision: $
Author: Ciaran McCreesh <ciaranm@gentoo.org>
Last-Modified: $Date: $
Status: Draft
Type: Standards Track
Content-Type: text/x-rst
Created: 31-Oct-2005
Post-History: 1-Nov-2005, 5-Nov-2005, 7-Nov-2005, 11-Dec-2005, 13-Dec-2005, 18-Dec-2005, 5-Jan-2006

Abstract
========

This GLEP proposes a new way of informing users about important updates and news
regarding tree-related items.

Motivation
==========

Although most package updates are clean and require little user action,
occasionally an upgrade requires user intervention during the upgrade process.
Recent examples of the latter include the ``gcc-3.4`` stabilisation on ``x86``
and the ``mysql-4.1`` database format changes.

There are currently several ways of delivering important news items to our
users, none of them particularly effective:

* Gentoo Weekly News
* The ``gentoo-announce``, ``gentoo-user`` and ``gentoo-dev`` mailing lists
* The Gentoo Forums
* The main Gentoo website
* RSS feeds of Gentoo news
* ``einfo`` and ``ewarn`` messages in ``pkg_setup`` or ``pkg_postinst``

A more reliable way of getting news of critical updates out to users is required
to avoid repeats of the various recent upgrade debacles. This GLEP proposes a
solution based around pushing news items out to the user via the ``rsync`` tree.

.. Important:: This GLEP does not seek to replace or modify ``einfo`` messages
   which are displayed post-install. That is a separate issue which is handled
   by ``elog`` [#bug-11359]_.

Requirements
============

An adequate solution must meet all of the following requirements:

Preemptive
    Users should be told of changes *before* they break a system, not after the
    damage has already been done. Ideally, the system administrator would be
    given ample warning to plan difficult upgrades and changes, rather than only
    being told just before action is necessary.

No user subscription required
    It has already been demonstrated [#forums-apache2]_ that many users do not
    read the ``gentoo-announce`` mailing list or ``RSS`` feeds. A solution which
    requires subscription has no advantage over current methods.

No user monitoring required
    It has already been demonstrated [#forums-apache2]_ that many users do not
    read news items posted to the Gentoo website, or do not read news items
    until it is too late. A solution that relies upon active monitoring of a
    particular source has no advantage over current methods.

Relevant
    System administrators who do not use a particular package should not have to
    read news items which affect purely that package. Some news items may be of
    relevance to most or all users, but those that are not should not be forced
    upon users unnecessarily.

Lightweight
    It is not reasonable to expect all users to have an MTA, web browser, email
    client, cron daemon or text processing suite available on their system.
    Users must not be forced to install unreasonable extra software to be able
    to read news items.

No privacy violations
    Users of the solution should not be required to provide information about
    their systems (for example, IP addresses or installed packages).

Multiple delivery method support
    Some users may wish to view news items via email, some via a terminal and
    some via a web browser. A solution should either support all of these
    methods or (better still) make it simple to write clients for displaying
    news items in different ways.

The following characteristics would be desirable:

Internationalisable
    Being able to provide messages in multiple languages may be beneficial.

Quality control
    There should be some way to ensure that badly written or irrelevant messages
    are not sent out, for example by inexperienced developers or those whose
    English language skills are below par.

Simple for developers
    Posting news items should be as simple as is reasonably possible.

Simple for users
    Reading relevant news items should be as simple as is reasonably possible.

Compatibility with existing and future news sources
    A news system would ideally be able to be integrated with existing news
    sources (for example, Forums, GWN, the main Gentoo website) without
    excessive difficulty. Similarly, easy interoperation with any future news
    sources should not be precluded.

Specification
=============

Overview
--------

News items are published and delivered to users as follows:

1. A news item is written. The format to be used is described below.

2. The news item is reviewed, following the process described in
   `News Item Quality Control`_.

3. The news item is committed to a CVS (or Subversion [#glep-36]_) repository.
   From here, it is merged with the rsync tree. This is described in `News Item
   Distribution`_.

4. Users fetch the news item when they sync. This ensures that the news items in
   question are pushed to the user before the user accidentally makes an
   unwanted change. No changes to the existing rsync process are required by
   this GLEP.

5. The package manager filters the news item and, if it is relevant, marks the
   news item for reading. The package manager should also display a notice
   informing the user that there are unread news items.

6. The news item is handled by the user's choice of news item reader. See `News
   Item Clients`_.

Required Portage Enhancements
-----------------------------

The following extensions to Portage are required:

* Every repository (including overlays) will require a unique identifier. It is
  assumed that an identifier will be a string consisting of characters from
  ``a`` to ``z``, ``A`` to ``Z``, ``0`` to ``9``, ``+`` (plus), ``-`` (hyphen)
  ``_`` (underscore).

* Portage must provide a way for external programs to obtain a list of all
  repository identifiers for a given system. It is assumed that this will be in
  the form of a ``portageq`` command (e.g. ``portageq get_repo_ids``).

* Portage must provide a way for external programs to obtain the base path for
  a repository with a given ID. It is assumed that this will be in the form of
  a ``portageq`` command (e.g. ``portageq get_repo_root gentoo-x86``).

* Portage must extend ``portageq has_version`` to support restrictions to a
  given repository ID.

* Portage must extend ``portageq`` to implement a command which returns whether
  or not the profile used for a given repository ID matches a certain base path
  (e.g. ``portageq profile_used default-linux/sparc/sparc64/2004.3 gentoo-x86``).

These extensions are assumed during the following specification.

News Item Identities
--------------------

Each news item will have a unique identifier. This identifier will be in the
form ``yyyy-mm-dd-short-name``, where ``yyyy`` is the year (e.g. ``2005``),
``mm`` is the month (``01`` through ``12``) and dd is the day of the month
(``01`` through ``31``). The ``short-name`` is a very short name describing the
news item (e.g. ``yoursql-updates``), consisting only of the characters ``a-z``,
``0-9``, ``+`` (plus), ``-`` (hyphen) and ``_`` (underscore).

News Item Directories
---------------------

Each news item will be represented by a directory whose name is the same as the
news item's identifier.

The directory will contain a file named ``yyyy-mm-dd-short-name.en.txt``, which
contains the text of the news item, in English, in the format described below.

If a news item is translated, other files named ``yyyy-mm-dd-short-name.xx.txt``
(where ``xx`` is the ISO 639 [#iso-639]_ two letter country code) will also be
provided. However, only the English version of a news item is authoritative.
This anglocentricity is justified by precedent [#glep-34]_.

News Item Files
---------------

A news item file is a text file, encoded using UTF-8 [#rfc-3629]_ for
compatibility with and for the same reasons as existing Gentoo documentation
[#docs-policy]_ and the tree [#glep-31]_.

News items must be signed with a detached GPG signature.::

    gpg --armour --detach-sign ????-??-??-*.??.txt

This GLEP does not specify the type or strength of signature to be used, nor
does it discuss how, if at all, a centralised keychain will be provided. These
issues should be handled as part of the signing policy discussions.

A news item file's content will consist of an RFC 822 style header [#rfc-822]_
followed by the main body of the message as plain text. This GLEP defines
various optional and mandatory headers. Future GLEPs may propose new headers —
tools handling these news items must ignore any unrecognised header.

News Item Headers
'''''''''''''''''

The following headers describe the purpose and format of the news item:

``Title:``
    A short (maximum 44 characters) descriptive title. Mandatory.

``Author:``
    Author's name and email address, in the form ``Real Name <email@address>``.
    Mandatory; multiple author headers may be specified if appropriate.

``Translator:``
    For translated news items, the translator's name and email address. Multiple
    translator headers may be specified if appropriate.

``Content-Type:``
    Must be ``text/plain``. Mandatory.

``Posted:``
    Date of posting, in ``yyyy-mm-dd`` format (e.g. 2005-12-18) for
    compatibility with GLEP 45 [#glep-45]_. Mandatory.

``Revision:``
    Initially 1. Should be incremented every time a change is made to the news
    item. Changes that require a re-read of the news item (i.e., most changes
    that are not spelling or formatting related) should instead use a new news
    item. Mandatory.

``News-Item-Format:``
    Must be ``1.0``. Future revisions to the format may increment the minor
    number for backwards-compatible changes, or the major number for major
    changes.

The following headers are used for filtering:

``Display-If-Installed:``
    A dependency atom (for example, ``<dev-lang/php-5_alpha`` or
    ``net-www/apache``). If the user has the package specified installed from
    the repository from which the news item was obtained, the news item should
    be displayed.

``Display-If-Keyword:``
    A keyword [#glep-22]_ name, for example ``mips`` or ``x86-fbsd``. If the
    user is on the keyword in question, the news item should be displayed.

``Display-If-Profile:``
    A profile path, for example ``default-linux/sparc/sparc64/server``. If the
    user is using the exact profile in question, or a subprofile of this
    profile, the news item should be displayed. This header may be used to
    replace ``deprecated`` files in the future.

.. Note:: When performing package moves, developers must also update any
   relevant ``Display-If-Installed`` headers in news files.

The algorithm used to determine whether a news item is 'relevant' is as
follows:

* For each ``Display-If-`` header type which occurs at least once:

  + The news item is not relevant if none of the headers of this type are
    successfully matched.

* Otherwise the news item is relevant.

In particular, if no ``Display-If-`` header is specified, a news item will be
relevant for all users.

This algorithm was chosen because it makes conditions like "display this news
item for ``YourSQL`` users who are on ``sparc`` or ``x86-obsd`` relatively
simple to specify — it is believed that these kinds of condition are far more
likely to occur than "display this news item for people using ``YourSQL``, or
for people on ``sparc`` or ``x86-obsd``\" or "display these news items for
people who use ``YourSQL`` and who are on both ``sparc`` and ``x86-obsd``\".

News Item Body
''''''''''''''

The header section must be followed by a blank line, then the main body of the
text.

The text body should be wrapped at 72 characters. No fancy formatting or tab
characters should be used — the news item may be being displayed directly to a
terminal. Paragraphs should be separated by a blank line.

Hyperlinks may be used to refer to further information (for example, an upgrade
guide). However, the main body of the news item should be descriptive and not
simply a "read this link" text. It is assumed that the user will have access to
a web browser *somewhere*, but not necessarily on the box which is being
administrated — this will be the case on many servers and routers, for example.

Example News Item
'''''''''''''''''

`This hypothetical news item`__ could be used for an upgrade to the
``YourSQL`` database format which breaks forward compatibility.

.. __: glep-0042-extras/example-news-item.txt

News Item Quality Control
-------------------------

There have been complaints regarding the comprehensibility of some upgrade
notices and news items in the past. This is understandable — not every Gentoo
developer speaks English as a first language. However, for the sake of clarity,
professionalism and avoiding making us look like prats, it is important that any
language problems be corrected before inflicting a news item upon end users.

Thus, at least 72 hours before a proposed news item is committed, it must be
posted to the ``gentoo-dev`` mailing list and ``Cc:``\ed to ``pr@gentoo.org``
(exceptions may be made in exceptional circumstances). Any complaints — for
example regarding wording, clarity or accuracy — **must** be addressed before
the news item goes live.

News items must only be for **important** changes that may cause serious upgrade
or compatibility problems. Ordinary upgrade messages and non-critical news items
should remain in ``einfo`` notices. The importance of the message to its
intended audience should be justified with the proposal.

.. Important:: The filtering system means that it is appropriate to send out
   news items which are aimed at users of an uncommon package or architecture.
   Thus, the justification should be in the form "this message is important to
   YourSQL users because ...", not "YourSQL is important because ...".

News Item Distribution
----------------------

Server Side
'''''''''''

News items are to be made available via the standard rsync tree. This removes
any need for polling of a remote source.

A new repository will be created for news items. The type (CVS or Subversion),
location and access controls on this repository are beyond the scope of this
GLEP.

.. Note:: A previous draft of this GLEP instead used the main ``gentoo-x86``
   tree. This was changed following advice from Infrastructure
   [#ramereth-repo]_. Both solutions have the same end result.

This repository will contain directories named ``yyyy/mm/``, where ``yyyy`` is
the current year and ``mm`` is the current month number (01 for January through
12 for December). This separation will help keep news items more manageable.

The contents of this repository will automatically be merged with the main rsync
tree, placing the items in a ``metadata/news/`` directory. The method used for
merging these items and the frequency at which it will occur is beyond the scope
of this GLEP; a similar setup is already used for merging GLSAs into the rsync
tree.

The main rsync tree will **not** use the ``yyyy/mm/`` subdirectory layout. The
news item directories will all be immediately under the ``metadata/news/``
directory.

Client Side
'''''''''''

Whenever relevant unread news items are found, the package manager will create a
file named ``/var/lib/gentoo/news/news-${repoid}.unread`` (if it does not
already exist) and append the news item identifier (eg
``2005-11-01-yoursql-updates``) on a new line.

All news item related files should be root owned and in the ``portage`` group
with the group write (and, for directories, execute) bits set. News files should
be world readable.

Notification that new relevant news items will be displayed via the
``emerge`` tool in a similar way to the existing "configuration files need
updating" messages:

::

    * Important: there are 5 unread news items.
    * Type emerge --help news to learn how to read news files.

Checks for new news messages should be displayed:

* After an ``emerge sync``
* After an ``emerge --pretend``
* Before an ``emerge <target>`` (which may also include a red warning message)

The package manager does not need to know how to launch the user's choice of
news client. This is consistent with the way configuration file updates are
handled.

The package manager may use a timestamp check file to avoid having to process
news items unnecessarily.

The package manager must keep track of news items that have already been added
to the unread list to avoid repeatedly marking a deleted news item. This could
be handled via a ``news-${repoid}.skip`` file containing the IDs of news items
that have already been added to a ``news-${repoid}.unread`` file, but this
method is not required by this GLEP.

Users who really don't care about news items can use ``rsync_excludes`` to
filter out the ``metadata/news/`` directory.

News Item Clients
-----------------

Once a news item is marked for reading, third party tools (or traditional core
Unix tools) can be used to display and view the news files.

When a news item is read, its name should be removed from the
``news-repoid.unread`` file. If a news client acts as an interactive reader
rather than a gateway, it should then add the name to a ``news-repoid.read``
file in the same directory with the same file format.

An ``eselect`` [#eselect]_ module shall be created as the 'suggested' display
tool; other display tools (for example, a news to email forwarder, which would
be ideal for users who sync on a ``cron``) are left as options for those who
desire them.

News Item Removal
-----------------

News items can be removed (by removing the news file from the main tree) when
they are no longer relevant, if they are made obsolete by a future news item or
after a long period of time. This is the same as the method used for ``updates``
entries.

Integration with Existing Systems
=================================

It would be simple to convert these news items into the format used for news
items on the Gentoo website or posts for the ``gentoo-announce`` mailing list.

There is an existing automated tool [#forums-glsa]_ for posting GLSAs to the
forums. A similar tool can be used for these news items.

Backwards Compatibility
=======================

Backwards compatibility is not a concern here. Existing tools will simply ignore
the ``news/`` directory.

Reference Implementation
========================

Portage Code
------------

TODO

Simple ``eselect`` News Client
------------------------------

TODO Removed until the exact format details are figured out.

Simple News to Mail Forwarder
-----------------------------

TODO Removed until the exact format details are figured out.

Credits
=======

The idea behind notifying users of news updates via Portage comes from Stuart
Herbert [#stuart-blog]_.

Thanks to Lance Albertson, Stephen Bennett, Donnie Berkholz, Grant Goodyear,
Brian Harring, Marius Mauch, Dan Meltzer, Jason Stubbs, Paul de Vrieze and Alec
Warner for input.  Some of the ideas presented here are theirs, others go
completely against their suggestions.

Example Files
=============

TODO Removed until the exact format details are figured out.

References
==========

.. [#bug-11359] Bugzilla Bug 11359
   "[NEW FEATURE] pkg_postinst/pkg_preinst ewarn/einfo logging",
   https://bugs.gentoo.org/show_bug.cgi?id=11359
.. [#docs-policy] Gentoo XML Guide, Daniel Robbins et al.,
     http://www.gentoo.org/doc/en/xml-guide.xml
.. [#eselect] eselect modular framework for configuration and
     administration utilities,
     http://www.gentoo.org/proj/en/eselect/index.xml
.. [#forums-glsa] Forums user GLSA,
     http://forums.gentoo.org/profile.php?mode=viewprofile&u=55648
.. [#forums-apache2] Forums thread "Gentoo Apache2 Config Change Idiocy",
     http://forums.gentoo.org/viewtopic-t-384368.html
.. [#glep-22] GLEP 22: "New "keyword" system to incorporate various
     userlands/kernels/archs", Grant Goodyear,
     http://www.gentoo.org/proj/en/glep/glep-0022.html
.. [#glep-31] GLEP 31: "Character Sets for Portage Tree Items", Ciaran
     McCreesh,
     http://www.gentoo.org/proj/en/glep/glep-0031.html
.. [#glep-34] GLEP 34: "Per-Category metadata.xml Files", Ciaran McCreesh,
     http://www.gentoo.org/proj/en/glep/glep-0034.html
.. [#glep-36] GLEP 36: "Subversion/CVS for Gentoo Hosted Projects", Aaron
     Walker,
     http://www.gentoo.org/proj/en/glep/glep-0036.html
.. [#glep-45] GLEP 45: "GLEP date format", Henrik Brix Andersen,
     http://www.gentoo.org/proj/en/glep/glep-0045.html
.. [#iso-639] ISO 639 "Code for the representation of names of languages"
.. [#ramereth-repo] "Re: [gentoo-dev] GLEP ??: Critical News Reporting", Lance
     Albertson,
     http://marc.theaimsgroup.com/?l=gentoo-dev&m=113111585907703&w=2
.. [#rfc-822] RFC 822 "Standard for the format of ARPA Internet text messages"
.. [#rfc-3629] RFC 3629: "UTF-8, a transformation format of ISO 10646"
       http://www.ietf.org/rfc/rfc3629.txt
.. [#stuart-blog] "Favouring an automatic news mechanism", Stuart Herbert,
     http://stu.gnqs.org/diary/gentoo.php/2005/10/28/favouring_an_automatic_news_mechanism

Copyright
=========

This document has been placed in the public domain.

.. vim: set tw=80 fileencoding=utf-8 spell spelllang=en et :