2004.04_Wikis-Discover How to Build Wikis with Moinmoin.pdf

KNOW HOW

MoinMoin Wiki

Creative Group Writing

The members of a project team can

profit from collecting their ideas, or

any loose ends, in a central repository.

Wikis are tailor-made for this task.

BY HEIKE JURZIK

ment systems started to

appear for website manage-

ment, Wikis provided a kind of “open

door” to HTML pages, allowing any visi-

tor to click and edit the HTML content.

Wiki is the abbreviation for WikiWiki-

Web – “wiki wiki” is derived from

Hawaiian and means “quick” or

“quickly”. And the open authoring sys-

tem certainly is quick. The MoinMoin

Wiki engine is one of the better-known

implementations of this technology.

Users can click to launch the embed-

ded editor and access the content and

structure of the page they want to mod-

ify. Typically, an Edit link is provided to

make things easier.

In contrast to “real” HTML, which

uses format tags, wikis have a special

syntax that needs only a few simple for-

matting commands.

The wiki web page version control sys-

tems ensure that older versions can be

restored at any time, should a page be

deleted or damaged by mistake. Also,

wikis allow you to assign special access

controls that can restrict editing to regis-

tered users, if required.

The first wiki website was published

by Ward Cunningham in 1995, and it is

still online [1]. At the time, Cunningham

wrote an email message saying that he

had programmed a new kind of database

“I’ve put up a new database on my web

server(…). It’s a web of people, projects

and patterns accessed through a cgi -bin

script.” [2].

This meant opening up his HTML

pages to the general public. The foot of

each wiki page contains a link that takes

users to the editor where they can add

to, or modify, pages. Fortunately, there is

no need to write HTML code to do so.

Cunningham wanted to make things eas-

ier for the authors and so chose a

simpler syntax.

The Wiki engine stores the content

input either as ASCII text, or externally

using a relational database such as

MySQL, Oracle, or PostgreSQL. The soft-

ware then uses this data to create the

public HTML pages.

Besides taking a look at the original

wiki, you might like to visit what is cur-

rently the biggest wiki on the Web, the

Wikipedia [3], which offers innumerable

articles on pages in multiple languages.

It is an example of how well information

can be organized with a wiki.

If you are thinking of running a wiki

yourself, you will be spoilt for choice of

software – there are over 100 different

wiki engines [4], most of which are

Open Source. In this article we will be

looking at the MoinMoin engine, and

introducing its syntax.

GLOSSARY

CGI :CGI is the abbreviation for C ommon

G ateway I nterface. It provides an interface

between external programs, or scripts, and

the web server. While HTML pages are static,

CGIs allow for content generation at runtime.

Programs in the web server’s “cgi-bin” direc-

tory are run automatically by the server

when requested by a browser. For example,

CGI scripts process the input from forms on

HTML pages.

Pre-Flight Check

Before we launch into the wiki installa-

tion, let’s first ensure that a few other

services are running on your machine.

These include Apache [5], for example.

Most current distributions include pack-

ages with versions 1 and 2 of the web

server. You will not normally need to

April 2004

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Building wikis with MoinMoin Wiki

W ay before content manage-

MoinMoin Wiki

KNOW HOW

Figure 1: Good morning – MoinMoin shortly after take off.

Figure 2: Using MoinMoin as a template.

compile the sources manually. Moin-

Moin [6] is a Wiki based on the Python

[7] scripting language. Make sure that

Python is installed on your machine, by

typing python -V , and if not, install the

Python packages from your distribu-

tion’s installation CDs.

huhnix:/moin-1.1 # egrep "^User U

|^Group" /etc/httpd/httpd.conf

User wwwrun

Group nogroup

ScriptAlias /mywiki "/usr/local U

/share/moin/mywiki/moin.cgi"

You only need the first line once in the

configuration file; the second line is

required for each wiki instance on the

server – make sure you change the name

and path. Avoid calling your wiki wiki if

you can, as this can cause name conflicts

with internal software components.

Finally, re-launch the web server

( /etc/init.d/apache2 restart for Apache 2,

/etc/init.d/apache restart for Apache 1,

and /etc/init.d/httpd restart for Red Hat

Linux). If you then access the URL

http://localhost/mywiki/ with your brow-

ser, you should see the wiki welcome

page (see Figure 1).

Red Hat Linux users will need to parse

/etc/httpd/conf/httpd.conf instead, and

Debian Linux uses /etc/apache/httpd.

conf .

Now change to the moin directory ( cd

/usr/share/moin/ or cd /usr/local/share/

moin/ ) to create a new Wiki instance:

MoinMoin Sources

The MoinMoin sources can be down-

loaded from the project homepage. Type

tar xzvf moin-1.1.tar.gz to unpack the

archive, then change to the new direc-

tory created by this process ( cd

moin-1.1 ) and assume root privileges.

Python can help you install the software.

The command is as follows:

mkdir mywiki

cp -r data mywiki

cp cgi-bin/* mywiki

chown -R wwwrun.nogroup mywiki

chmod a+rx mywiki/*.cgi

huhnix:/moin-1.1 # python setup U

.py install --record=install.log

running install

running build

running build_py

creating build

creating build/lib

creating build/lib/MoinMoin

[...]

Debian users will need to change the IDs

in the chown line to www-data.www-

data , and Red Hat Linux users to apache.

apache . The two entries then

need to be added to the

Apache configuration file (this

is /etc/httpd/httpd.conf for

Apache 1 and /etc/apache2/

httpd.conf for Apache 2 on

Suse Linux, /etc/apache/httpd.

conf for Debian, and /etc/

httpd/conf/httpd.conf for Red

Hat Linux):

Sandbox

When you are trying out your new wiki,

it makes sense to take your first steps in

Table 1: MoinMoin Syntax

Wiki Syntax

HTML Syntax

Displays as

"italics"

<em>italics</em>

italics

"'bold'"

bold

##comment

not displayed as output

The --record=install.log parameter

writes an overview of the steps to the

install.log file. The next step is to dis-

cover the user and group IDs that your

Apache server uses. You can grep the

Apache configuration file to find these

values. On Suse Linux 8.2, for example,

type the following:

[[BR]]

<br>

hard newline

New line

<p>

Paragraph

= Heading =

<h1>Heading</h1>

Heading

== Subheading ==

<h2>Subheading</h2> Subheading

=== Level 3 ===

<h3>Level 3</h3>

Level 3

Alias /wiki/ U

"/usr/share/moin/ U

htdocs/"

==== Level 4 ====

<h4>Level 4 </h4>

Level 4

===== Level 5 ===== <h5>Level 5</h5>

Level 5

—- (four dashes)

<hr>

horizontal line

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April 2004

KNOW HOW

MoinMoin Wiki

the so-called sandbox,

which you can access

via a link on the wel-

come page ( http://local

host/mywiki/WikiSand

Box ). Click on the Edit

this page link to open a

window within the win-

dow. Most formatting

commands are intuitive

and you will soon dis-

cover that you have

mastered them. Table 1

provides on overview of

the most important com-

mands.

There are different

techniques for creating

links. To refer to an

external page on the

Web, simply supply the

URL, but make sure that you include

http:// . For example, http://www.

linux-magazine.com is a valid reference,

but not www.linux-magazine.com .

You can use straight brackets to

provide an additional description of the

link – [http://www.linux-magazine.com

Linux Magazine homepage] . This would

be written as <a href="http://www.

linux-magazine.com">Linux Magazine

Homepage</a> in HTML.

Internal links to wiki pages use the so-

called “CamelCase” notation with a

capital letter at the start of, and some-

where inside the word. For example, you

could easily use LinuxMagazine as a link

to the page http://localhost/mywiki/

LinuxMagazine .

If this does not currently exist, Moin-

Moin will help you create it (see Figure

2). Incidentally, if you add the Moin-

Moin: prefix to an internal link, the wiki

engine will create a link to the official

MoinMoin wiki. Thus, the following

link, MoinMoin:LinuxMagazine , would

take you to the following page http://

purl.net/wiki/moin/LinuxMagazine .

tent directly from the

server. Normal users are

not allowed to delete

pages, unless you explic-

itly allow them to do so

in the configuration file,

/usr/share/moin/

mywiki/moin_config.py .

Should you require this,

add the following line:

allowed_actions= U

['DeletePage']

Figure 3: Using your own logo.

This displays a Delete

Page link to visitors of

the wiki site. If a user

clicks on the link, Moin-

Moin ask them to con-

firm and then enter a

reason for this action.

To prevent pages disappearing mysteri-

ously, the software saves backup copies

of deleted pages in /usr/share/moin/

mywiki/data/backup/ . If you want to

check on recent developments, you can

click on RecentChanges at the top of any

page to see where people are currently

working.

The MoinMoin developers are working

on individual user account based access

privileges, and this feature is already

available in the 1.1 version along with

ACL support.

Wikis basically do not provide security

– this is something all administrators

should be aware of. If you run an open

wiki on the Web, you are practically ask-

ing for graffiti.

However, a wiki on your Intranet can

be a useful thing. The ease of use, and

the fact that users do not need an

account on the web server to edit a page,

mean that a wiki software makes a lot of

sense for non-technical users.

the warning sign. A table with the avail-

able smileys and a note on how to

produce them is available at http://

localhost/mywiki/HelpOnSmileys .

/usr/share/moin/htdocs/img/ contains

miscellaneous images, such as the Moin-

Moin logo, moinmoin.gif . If you want to

use your own logo or image (see Figure

3) on your wiki pages, rather than the

man with the “Moin, Moin!” sign, sim-

ply save the image file in /usr/share/

moin/htdocs/img/ and the edit the /usr/

share/moin/mywiki/moin_config.py file.

The entry will need to read:

logo_url = url_prefix + '/img U

/ Your_Imagefile '

This allows you to reflect corporate, or

organizational, identity when designing

a wiki site for a project or your organiza-

tion’s Intranet.

Use the /usr/share/moin/mywiki/moin

_config.py file to edit the name of your

wiki instance. To do so, replace the

default value, which is represented by

the sitename variable, with your choice

of name, as in sitename = ‘Brainstorm-

ing Special Issue . This will display the

name as a heading in your browser.

■

INFO

[1] WikiWikiWeb: http://c2.com/cgi/wiki

[2] Email announcement: http://c2.com/

wiki/mail-history.txt

[3] Wikipedia: http://en.wikipedia.org/

[4] Wiki engines: http://c2.com/cgi/

wiki?WikiEngines

[5] Apache: http://www.apache.org

[6] MoinMoin: http://moin.sourceforge.net

[7] Python: http://www.python.org

Under the Hood

/usr/share/moin/htdocs/img/ contains a

number of GIF-formatted image files

which the wiki uses. These include all

kinds of smileys (emoticons). The wiki

software uses these images if certain

character strings appear in the text. The

wiki also adds a few symbols of its own,

such as the Python logo on each page, or

Open Wikis, Open Doors?

Wiki administrators have a few impor-

tant tasks to take care of, such as

maintaining the pages. Pages are located

in the wiki’s data/text/ subdirectory. You

can use the rm command to delete con-

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