variables_in_config.xml

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  Copyright (C) Nginx, Inc.
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<!DOCTYPE article SYSTEM "../../../../dtd/article.dtd">

<article name="Is there a proper way to use nginx variables to
               make sections of the configuration shorter,
               using them as macros for making
               parts of configuration work as templates?"
         link="/en/docs/faq/variables_in_config.html"
         lang="en"
         rev="1">

<section>

<para>
<initial>Q:</initial>
Is there a proper way to use nginx variables to make sections of
the configuration shorter, using them as macros for making
parts of configuration work as templates?
</para>

<para>
&nbsp;
</para>

<para>
<initial>A:</initial>
Variables should not be used as template macros. Variables are
evaluated in the run-time during the processing of each
request, so they are rather costly compared to plain static
configuration. Using variables to store static strings is also
a bad idea. Instead, a macro expansion and "include" directives
should be used to generate configs more easily and it can be
done with the external tools, e.g. sed + make or any other
common template mechanism.
</para>

</section>

</article>