# Keyval
The module allows the use of variables with values from "key-value" pairs,
which are stored in shared memory or in a Redis store.
## Installation
To [install](https://en.angie.software//angie/docs/installation/index.md#install-packages) the module, use one of the following packages:
- Angie: `angie-module-keyval`
- Angie PRO: `angie-pro-module-keyval`
## Loading the Module
To work with the module, it must be loaded in the `main{}` context:
```nginx
load_module modules/ngx_http_keyval_module.so;
```
## Configuration Example
```nginx
keyval_zone zone=one:32k;
keyval $arg_key $value zone=one;
server {
listen 80;
server_name localhost;
location /get {
return 200 "key '$arg_key' has value = '$value'\\n";
}
location /set {
set $value $arg_value;
return 200 "'$arg_key' key added with '$arg_value' value\\n";
}
}
```
Adding and modifying entries in the shared memory zone 'one' is done by
assigning a value to the `$value` variable. The key value
is stored in the `$arg_key` variable. In this configuration, this is done via the
`set` directive:
```nginx
set $value $arg_value;
```
## Demonstration
Let's define some values using requests:
```console
$ curl "localhost/set/?key=one&value=TextForKeyOne"
'one' key added with 'TextForKeyOne' value
```
```console
$ curl "localhost/set/?key=two&value=TextForKeyTwo"
'two' key added with 'TextForKeyTwo' value
```
Let's check:
```console
$ curl "localhost/get/?key=one"
key 'one' has value = 'TextForKeyOne'
```
```console
$ curl "localhost/get/?key=two"
key 'two' has value = 'TextForKeyTwo'
```
## Using Redis
Let's modify the configuration to store "key-value" pairs in a Redis store:
```nginx
keyval_zone_redis zone=oneredis;
keyval $arg_key $value zone=oneredis;
server {
listen 80;
server_name localhost;
location /get {
return 200 "key '$arg_key' has value = '$value'\\n";
}
location /set {
set $value $arg_value;
return 200 "'$arg_key' key added with '$arg_value' value\\n";
}
}
```
Let's add a "key-value" pair to the Redis store via a request:
```console
$ curl "localhost/set/?key=one&value=TextForKeyOne"
'one' key added with 'TextForKeyOne' value
```
The same can be done using Redis itself:
```console
$ redis-cli
127.0.0.1:6379> set oneredis:two 'text for key two'
OK
127.0.0.1:6379>
```
Let's check:
```console
$ redis-cli --scan
"oneredis:one"
"oneredis:two"
```
```console
$ curl "localhost/get/?key=one"
key 'one' has value = 'TextForKeyOne'
```
```console
$ curl "localhost/get/?key=two"
key 'two' has value = 'text for key two'
```
## Additional Information
A complete description of the directives and the source code is available at:
[https://github.com/kjdev/nginx-keyval](https://github.com/kjdev/nginx-keyval).