@subheading Goals

@itemize
@item ...
@end itemize

@subheading Description

The CentOS web environment is formed by a central web application
---to cover base needs (e.g., per-major release information like
release notes, lifetime, downloads, documentation, support, security
advisories, bugs, etc.)--- and many different free web applications
---to cover specific needs (e.g., wiki, mailing lists, etc.)---. 

The CentOS web environment is addressed to solve the following issues:

@itemize
@item One unique name and one unique visual style to all web
applications used inside the web environment.

@item One-step navigation to web applications inside the environment.

@item High degree of customization to change the visual style of all
web applications with few changes (e.g, updating just two or three
images plus common style sheet [CSS] definitions).
@end itemize

The CentOS project is attached to a monolithic corporate visual
identity (@pxref{Directories trunk Identity}), where all visual manifestations
have one unique name and one unique visual style. This way, the CentOS
web environment has one unique name (the CentOS brand) and one unique
visual style (the CentOS default theme) for all its visual
manifestations, the web applications in this case.

Since a maintainance point of view, achiving the one unique visual
style inside CentOS web environment is not a simple task. The CentOS
web environment is built upon many different web applications which
have different visual styles and different internal ways to customize
their own visual styles. For example: MoinMoin, the web application
used to support the CentOS wiki (@url{http://wiki.centos.org/}) is
highly customizable but Mailman (in its 2.x.x serie), the web
application used to support the CentOS mailing list, doesn't
support@footnote{The theme support of Mailman may be introduced in
mailman-3.x.x release.} a customization system that separates
presentation from logic, similar to that used by MoinMoin.

This visual style diversity complicates our goal of one unique visual
style for all web applications. So, if we want one unique visual style
for all web applications used, it is innevitable to modify the web
applications in order to implement the CentOS one unique visual style
customization in them. Direct modification of upstream applications is
not convenient because upstream applications come with their one
visual style and administrators take the risk of loosing all
customization changes the next time the application be updated (since
not all upstream web applications, used in CentOS web environment,
separate presentation from logic).

To solve the ``one unique visual style'' issue, installation and
actualization of web applications ---used inside CentOS web
environment--- need to be independent from upstream web applications
development line; in a way that CentOS web environment administrators
can install and update web applications freely without risk of loosing
the one unique visual style customization changes. 

At the surface of this issue we can see the need of one specific yum
repository to store CentOS web environment customized web applications.

@subsubheading Design model (without ads)

@subsubheading Design model (with ads)

@subsubheading HTML definitions

@subsubheading Controlling visual style

Inside CentOS web environment, the visual style is controlled by the
following compenents:

@table @strong
@item Webenv header background
@verbatim
trunk/Identity/Images/Themes/$THEME/Backgrounds/Img/1024x250.png
@end verbatim

@item CSS definitions
@verbatim
trunk/Identity/Themes/Models/Default/Promo/Web/CSS/stylesheet.css
@end verbatim
@end table

@subsubheading Producing visual style

The visual style of CentOS web environment is defined in the following
files:

@verbatim
trunk/Identity/Images/Themes/$THEME/Backgrounds/Xcf/1024x250.xcf
trunk/Identity/Images/Themes/$THEME/Backgrounds/Img/1024x250.png
trunk/Identity/Images/Themes/$THEME/Backgrounds/Img/1024x250-bg.png
trunk/Identity/Images/Themes/$THEME/Backgrounds/Tpl/1024x250.svg
@end verbatim

As graphic designer you use @file{1024x250.xcf} file to produce
@file{1024x250-bg.png} file. Later, inside @file{1024x250.svg} file,
you use the @file{1024x250-bg.png} file as background layer to draw
your vectorial design. When you consider you artwork ready, use the
@command{centos-art.sh} script, as described below, to produce the
visual style controller images of CentOS web environment.

@verbatim
centos-art render --entry=trunk/Identity/Images/Themes/$THEME/Backgrounds --filter='1024x250'
@end verbatim

Once you have rendered required image files, changing the visual style
of CentOS web environment is a matter of replacing old image files
with new ones, inside webenv repository file system structure. The
visual style changes will take effect the next time customization line
of CentOS web applications be packaged, uploded, and installed from
[webenv] or [webenv-test] repositories.

@subsubheading Navigation

Inside CentOS web environment, the one-step navegation between web
applications is addressed using the web environment navigation bar.
The web environment navigation bar contains links to main applications
and is always visible no matter where you are inside the web
environment.

@subsubheading Development and release cycle

The CentOS web environment development and relase cycle is described
below: 

@table @strong

@item Download

The first action is download the source code of web applications we
want to use inside CentOS web environment.

@quotation
@strong{Important} The source location from which web application are
downloaded is very important. Use SRPMs from CentOS @strong{[base]}
and @strong{[updates]} repositories as first choise, and third party
repositories (e.g. RPMForge, EPEL, etc.) as last resource.
@end quotation

@item Prepare 

Once web application source code has been downloaded, our duty is
organize its files inside @samp{webenv} version controlled repository.

When preparing the structure keep in mind that different web
applications have different visual styles, and also different ways to
implement it. A convenient way to organize the file system structure
would be create one development line for each web application we use
inside CentOS web environment. For example, consider the following
file system structure:

@verbatim
https://projects.centos.org/svn/webenv/trunk/
|-- WebApp1/
|   |-- Sources/
|   |   `-- webapp1-0.0.1/
|   |-- Rpms/
|   |   `-- webapp1-0.0.1.rpm
|   |-- Srpms/
|   |   `-- webapp1-0.0.1.srpm
|   `-- Specs/
|       `-- webapp1-0.0.1.spec
|-- WebApp2/
`-- WebAppN/
@end verbatim

@item Customize

Once web applications have been organized inside the version
controlled repository file system, use subversion to create the CentOS
customization development line of web applications source code.  For
example, using the above file system structure, you can create the
customization development line of @file{webapp1-0.0.1/} with the
following command:

@verbatim
svn cp trunk/WebApp1/Sources/webapp1-0.0.1 trunk/WebApp1/Sources/webapp1-0.0.1-webenv
@end verbatim

The command above creates the following structure:

@verbatim
https://projects.centos.org/svn/webenv/trunk/
|-- WebApp1/
|   |-- Sources/
|   |   |-- webapp1-0.0.1/
|   |   `-- webapp1-0.0.1-webenv/
|   |-- Rpms/
|   |   `-- webapp1-0.0.1.rpm
|   |-- Srpms/
|   |   `-- webapp1-0.0.1.srpm
|   `-- Specs/
|       `-- webapp1-0.0.1.spec
|-- WebApp2/
`-- WebAppN/
@end verbatim

In the above structure, the @file{webapp1-0.0.1-webenv/} directory is
the place where you customize the visual style of
@file{webapp1-0.0.1/} web application. 

@quotation
@strong{Tip} Use the @command{diff} command of Subversion between
CentOS customization and upstream development lines to know what you
are changing exactly.
@end quotation

@item Build packages

When web application has been customized, build the web application
RPM and SRPM using the source location with @samp{-webenv} prefix. 

@verbatim
https://projects.centos.org/svn/webenv/trunk/
|-- WebApp1/
|   |-- Sources/
|   |   |-- webapp1-0.0.1/
|   |   `-- webapp1-0.0.1-webenv/
|   |-- Rpms/
|   |   |-- webapp1-0.0.1.rpm
|   |   `-- webapp1-0.0.1-webenv.rpm
|   |-- Srpms/
|   |   |-- webapp1-0.0.1.srpm
|   |   `-- webapp1-0.0.1-webenv.srpm
|   `-- Specs/
|       |-- webapp1-0.0.1.spec
|       `-- webapp1-0.0.1-webenv.spec
|-- WebApp2/
`-- WebAppN/
@end verbatim

@item Release for testing

When the customized web application has been packaged, make packages
available for testing and quality assurance. This can be achives using
a [webenv-test] yum repository. 

@quotation
@strong{Note} The [webenv-test] repository is not shipped inside
CentOS distribution default yum configuraiton. In order to use
[webenv-test] repository you need to configure it first.
@end quotation

If some problem is found to install/update/use the customized version
of web application, the problem is notified somewhere (a bugtracker
maybe) and the customization face is repated in order to fix the
problem. To release the new package add a number after @samp{-webenv}
prefix. For example, if some problem is found in
@file{webapp1-0.0.1-webenv.rpm}, when it be fixed the new package will
be named @file{webapp1-0.0.1-webenv-1.rpm}. If a problem is found in
@file{webapp1-0.0.1-webenv-1.rpm}, when it be fixed the new package
will be named @file{webapp1-0.0.1-webenv-2.rpm}, and so on.

The ``customization --- release for testing'' process is repeated
until CentOS quality assurance team considers the package is ready for
production.

@item Release for production

When customized web application packages are considered ready for
production they are moved from [webenv-test] to [webenv] repository.
This action is commited by CentOS quality assurance team.

@quotation
@strong{Note} The [webenv] repository is not shipped inside CentOS
distribution default yum configuraiton. In order to use [webenv]
repository you need to configure it first.
@end quotation
@end table

@subsubheading The [webenv-test] repository

@verbatim
/etc/yum.repos.d/CentOS-Webenv-test.repo
@end verbatim

@verbatim
[webenv-test]
name=CentOS-$releasever - Webenv-test
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=webenv-test
#baseurl=http://mirror.centos.org/centos/$releasever/webenv-test/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-$releasever
enabled=1
priority=10
@end verbatim

@subsubheading The [webenv] repository

@verbatim
/etc/yum.repos.d/CentOS-Webenv.repo
@end verbatim

@verbatim
[webenv]
name=CentOS-$releasever - Webenv
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=webenv
#baseurl=http://mirror.centos.org/centos/$releasever/webenv/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-$releasever
enabled=1
priority=10
@end verbatim

@subsubheading Priority configuration

Both [webenv] and [webenv-test] repositories update packages inside
CentOS [base] and CentOS [updates] repositories.

@subheading Usage

@itemize
@item ...
@end itemize

@subheading See also

@menu
@end menu