00-Foreword01.tut

= Foreword =

I've been doing a lot of work in the Nginx world over the last few years and
I've also been thinking about writing a series of tutorial-like articles to
explain to more people what I've done and what I've learned in this area. Now I
have finally decided to post serial articles to the Sina Blog
L<http://blog.sina.com.cn/openresty> in Chinese. Every article will roughly
cover a single topic and will be in a rather casual style. But at some point in
the future I may restructure the articles and their style in order to turn them
into a "real" book.

The articles are divided into series. For example, the first series is
"Nginx Variables". Each series can be thought of as mapping to a chapter in the
Nginx book that I may publish in the future.

The articles are intended for Nginx users of all experience levels, including
users with extensive Apache and Lighttpd experience who may have never used
Nginx before.

The examples in the articles are at least compatible with Nginx C<0.8.54>. Do
not try the examples with older versions of Nginx. The latest stable version of
Nginx as of this writing is C<1.7.9>.

All of the Nginx modules referenced in the articles are production-ready. I will
not be covering any Nginx core modules that are either experimental or buggy.
Additionally, I will be making extensive use of 3rd-party Nginx modules in the
examples. If it's inconvenient for you to download and install the individual
modules one at a time then I highly recommend that you download and install the
C<ngx_openresty> software bundle that I maintain.

L<http://openresty.org/|http://openresty.org/>

All of the modules referenced in the articles, including the core Nginx modules
that are new (but stable), are included in the OpenResty bundle.

A principle that I will be trying to adhere to is to use small concise examples
to explain and validate the concepts and behaviors being described. My hope is
that it will help the reader to develop the good habit of not accepting others'
viewpoints or statements at face value without testing them first. This approach
may have something to do with my QA background. In fact, I keep tweaking and
correcting the articles based on the results of running the examples while
writing.

The examples in the articles fall into one of two categories, good and
problematic. The purpose of the problematic examples is to highlight potential
pitfalls and other areas where Nginx or its modules behave in ways that readers
may not expect. Problematic examples are easy to identify because each line of
text in the example will be prefixed with a question mark, i.e., "C<?>". Here is
an example:

    :nginx
    ? server {
    ?     listen 8080;
    ?
    ?     location /bad {
    ?         echo $foo;
    ?     }
    ? }

Do not reproduce these articles without explicit permissions from us. Copyright
reserved.

I encourage readers to send feedback (C<agentzh@gmail.com>), especially
constructive criticism.

The source for all the articles is on GitHub:

L<http://github.com/agentzh/nginx-tutorials/>

The source files are under the F<en/> directory. I am using a little markup
language that is a mixture of C<Wiki> and C<POD> to write these articles. They
are the F<.tut> files. You are welcome to create forks and/or provide patches.

The e-books files that are suitable for cellphones, Kindle, iPad/iPhone,
Sony Readers, and other devices can be downloaded from here:

L<http://openresty.org/#eBooks>

Special thanks go to Kai Wu (kai10k) who kindly translates these articles to
English.

agentzh at home in the Fuzhou city

October 30, 2011