Don't Trip on the Red Carpet, Evolve with GNOME CVS
Looking at Red Carpet

Michael Hall
Friday, February 23, 2001 09:00:10 AM
So, at long last, down to the big item for the week which is Red
Carpet.
People who have been downloading and using Ximian's GNOME desktop distribution for
a while are pretty familiar with both the GUI installer and update
tool Ximian uses to ease acquisition of their software. Red Carpet is
the next generation of these tools, designed to not only make getting
the basic desktop easier but providing an easy-to-use method for
handling all packages on a given machine. In addition, Red Carpet
will eventually be used to deliver commercial software from Ximian
partners.
Getting Red Carpet
Red Hat 6/7 users can get Red Carpet via the current Ximian Updater by
pointing it at the Red Carpet mirror. Debian users can add the
following line to /etc/apt/sources.list:
deb ftp://spidermonkey.ximian.com/pub/red-carpet/binary/debian-22-i386/ ./
Keep in mind that installation of Red Carpet will, for the moment,
break current snapshots of Evolution you may have on your machine,
requiring installation of gtkhtml as detailed earlier in this column.
Red Carpet expects to find either Red Hat 6/7 or a Debian system in
place. It didn't work on a Progeny Debian machine, which is based
largely on Debian's Woody release, but did work on a Potato-based
system.
Channel Surfing
Red Carpet describes the groupings of packages it presents as
"channels". Users can subscribe to several possible channels at this
point. On a Debian machine, the available channels included the
Ximian GNOME desktop, Evolution snapshots, the Red Carpet release
itself, and the Debian archives.
By subscribing to a channel, users can keep abreast of a specific
project or collection of files. Once subscribed, Red Carpet downloads
status information on the packages in a given channel at startup and
notifies users of how many updates exist and how large a download
they represent.
The channel concept is handy because it gives Red Carpet a certain
level of versatility. It's possible to settle for simple package
management for a vanilla installation by subscribing only to the
basics, such as Ximian's GNOME desktop and the distribution's basic
archive. For users who feel like following projects under heavy
development, such as Evolution, adding a channel for that project
makes for a painless way to keep up with the project without missing
out on the latest developments because they're buried in with the more
mundane basic packages. On the flipside, all those interesting
bleeding-edge projects won't distract from the potentially more
important business of keeping track of security updates and bug fixes
for essential packages.
Using Red Carpet
Upon selecting a channel, users are presented with install
and remove options. Selecting the install option
presents a list of all the available packages in a given channel. The
list is cleanly presented, showing the package name, the available
version, and its size. In the preferences, there's a very nice option
for selecting "pretty package names." Ximian has taken the time to
provide easy-to-understand names for many packages with
sometimes-obscure names. "xsane" for instance, changes to "Graphical
Scanner Program (xsane)" under the naming scheme.
In addition to the clearer package names, a small information icon can
be clicked by each package that presents a more verbose description of
what the package does.
After the user selects packages for installation, Red Carpet presents
a screen that provides some information on the downloads required. In
addition to delivering the packages, Red Carpet also tracks and draws
in any package dependencies and handles conflicts by notifying the
user of any required removals. This is similar in practice to
Debian's dselect or apt-get, or tools like gnorpm, but the process is
much simpler than dselect (since there are fewer options) and presents
a little cleaner interface than gnorpm. Red Carpet also takes the
additional hand-holding step of warning that removing packages is a
sometimes-risky proposition.
Getting the file for installation involves four stages:
- Downloading
- Verifying
- Installing
- Configuring
During download, users who access the 'net via modem or working in
similarly bandwidth-constrained situations have the option to pause
the file transfer. According to Ximian, it's possible to pause the
download and disconnect from the 'net entirely in order to place a
phone call, for instance, and then reconnect and resume the transfer.
The verification stage allows Red Carpet to compare cryptographic
signatures on the packages to ensure they come from a reliable source,
and it offers a warning if a package is unsigned/unverifiable. The
usefulness for this in eventual commercial applications seems clear.
The installation and configuration stages involve unpacking the files
in question and presenting dialog boxes for any configuration
options. When I installed the gnome-pilot package, for instance,
was presented with a small window prompting for the serial port on
which our Pilot was connected.
Uninstalling packages was also simple: users select which packages
should come off the system, Red Carpet checks for broken dependencies
and handles the removal.
In addition to adding and removing packages and summarizing
availability, Red Carpet offers a "news" page that provides brief
headlines and information from Ximian which are downloaded at startup.
The news page could turn Red Carpet into a really useful conduit for
information about what's going on with Ximian and GNOME in general if
Ximian chooses to keep the news feed updated. The thought of being
able to check in on the latest by firing up a relatively small
application as opposed to a full-blown web browser is a pleasant one,
especially since that application then provides a streamlined means to
acting on the information by downloading new stuff or updating
existing packages on the spot.
Next: Wrapping up on Red Carpet »