User:MGorny/GLEP:42

GLEP 42: Critical News Reporting
Type	Standards Track
Status	Final
Author	Ciaran McCreesh <ciaranm@gentoo.org>, Stephen Bennett <spb@gentoo.org>, Zach Medico <zmedico@gentoo.org>
Editor
Replaces
Replaced by	(none)
Requires
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Abstract

This GLEP proposes a new way of informing users about important updates and news related to the tree.

Motivation

Although most package updates are clean and require little user action, occasionally an upgrade requires user intervention. 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 various prior 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

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 that many users do not read the gentoo-announce mailing list or RSS feeds. A solution that requires subscription has no advantage over current methods.

No user monitoring required

It has already been demonstrated 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 ) 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 is exactly the given profile (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 two letter language code, and the date remains the same as the original news item) will also be provided. However, only the English version of a news item is authoritative. This anglocentricity is justified by precedent .

News Item Files

A news item file is a text file, encoded using UTF-8 for compatibility with and for the same reasons as existing Gentoo documentation and the tree .

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 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 . Translations should use the date of the original news item. 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 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, 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.

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 . Both solutions have the same end result.

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.

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 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 ) 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 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

A reference implementation of the required package manager support can be found in Paludis , along with a reference newsreader implemented as an eselect module .

Credits

The idea behind notifying users of news updates via Portage comes from Stuart Herbert .

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

example-news-item.txt An example news item.

Copyright

This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/.