<?xml version="1.0"?>

<!--
  Copyright (C) Nginx, Inc.
  -->

<!DOCTYPE module SYSTEM "../../../../dtd/module.dtd">

<module name="Module ngx_http_keyval_module"
        link="/en/docs/http/ngx_http_keyval_module.html"
        lang="en"
        rev="5">

<section id="summary">

<para>
The <literal>ngx_http_keyval_module</literal> module (1.13.3) creates variables
with values taken from key-value pairs managed by the
<link doc="ngx_http_api_module.xml" id="http_keyvals_">API</link>.
</para>

<para>
<note>
This module is available as part of our
<commercial_version>commercial subscription</commercial_version>.
</note>
</para>

</section>


<section id="example" name="Example Configuration">

<para>
<example>
http {

    keyval_zone zone=one:32k state=one.keyval;
    keyval $arg_text $text zone=one;
    ...
    server {
        ...
        location / {
            return 200 $text;
        }

        location /api {
            api write=on;
        }
    }
}
</example>
</para>

</section>


<section id="directives" name="Directives">

<directive name="keyval">
<syntax>
    <value>key</value>
    <value>$variable</value>
    <literal>zone</literal>=<value>name</value></syntax>
<default/>
<context>http</context>

<para>
Creates a new <value>$variable</value> whose value
is looked up by the <value>key</value> in the key-value database.
Strings are matched ignoring the case.
The database is stored in a shared memory zone
specified by the <literal>zone</literal> parameter.
</para>

</directive>


<directive name="keyval_zone">
<syntax>
    <literal>zone</literal>=<value>name</value>:<value>size</value>
    [<literal>state</literal>=<value>file</value>]
    [<literal>timeout</literal>=<value>time</value>]
    [<literal>type</literal>=<literal>string</literal>|<literal>ip</literal>]
    [<literal>sync</literal>]</syntax>
<default/>
<context>http</context>

<para>
Sets the <value>name</value> and <value>size</value> of the shared memory zone
that keeps the key-value database.
Key-value pairs are managed by the
<link doc="ngx_http_api_module.xml" id="http_keyvals_">API</link>.
</para>

<para id="keyval_state">
The optional <literal>state</literal> parameter specifies a <value>file</value>
that keeps the current state of the key-value database in the JSON format
and makes it persistent across nginx restarts.
</para>

<para id="keyval_timeout">
The optional <literal>timeout</literal> parameter (1.15.0) sets
the time after which key-value pairs are removed from the zone.
</para>

<para id="keyval_type">
The optional <literal>type</literal> parameter (1.17.1) specifies
the type of the key:
a <literal>string</literal> (default) or <literal>ip</literal>.
For the <literal>ip</literal> type,
the key must be the textual representation of an IP address
specified in CIDR notation.
In this case,
an additional index optimized for matching IP addresses and networks is used
in evaluating a variable.
</para>

<para id="keyval_sync">
The optional <literal>sync</literal> parameter (1.15.0) enables
<link doc="../stream/ngx_stream_zone_sync_module.xml" id="zone_sync">synchronization</link>
of the shared memory zone.
The synchronization requires the
<literal>timeout</literal> parameter to be set.
<note>
If the synchronization is enabled, removal of key-value pairs (no matter
<link doc="ngx_http_api_module.xml" id="patchHttpKeyvalZoneKeyValue">one</link>
or
<link doc="ngx_http_api_module.xml" id="deleteHttpKeyvalZoneData">all</link>)
will be performed only on a target cluster node.
The same key-value pairs on other cluster nodes
will be removed upon <literal>timeout</literal>.
</note>
</para>

</directive>

</section>

</module>