# omhiredis: Redis Output Module

Module Name: omhiredis

Original Author: Brian Knox <bknox@digitalocean.com>

Description

This module provides native support for writing to Redis, using the hiredis client library.

Action Parameters

Note: parameter names are case-insensitive.

- server Name or address of the Redis server
- serverport Port of the Redis server if the server is not listening on the default port.
- serverpassword Password to support authenticated redis database server to push messages across networks and datacenters. Parameter is optional if not provided AUTH command wont be sent to the server.
- mode Mode to run the output action in: “queue” or “publish”. If not supplied, the original “template” mode is used. Note due to a config parsing bug in 8.13, explicitly setting this to “template” mode will result in a config parsing error.
- template Template is required if using “template” mode.
- key Key is required if using “publish” or “queue” mode.
- userpush if set to on, use RPUSH instead of LPUSH, if not set or off, use LPUSH.

Examples

Mode: template

In “template” mode, the string constructed by the template is sent to Redis as a command. Note this mode has problems with strings with spaces in them - full message won’t work correctly. In this mode, the template argument is required, and the key argument is meaningless.

::

  module(load=”omhiredis”)

  template(
    name=”program_count_tmpl” type=”string” string=”HINCRBY progcount %programname% 1”)
  action(
    name=”count_programs” server=”my-redis-server.example.com” serverport=”6379” type=”omhiredis” mode=”template” template=”program_count_tmpl”)

Here’s an example redis-cli session where we HGETALL the counts:

::
  > redis-cli 127.0.0.1:6379> HGETALL progcount 1) “rsyslogd” 2) “35” 3) “rsyslogd-pstats” 4) “4302”

Mode: queue

In “queue” mode, the syslog message is pushed into a Redis list at “key”, using the LPUSH command. If a template is not supplied, the plugin will default to the RSYSLOG_ForwardFormat template.

::

  module(load=”omhiredis”)

  action(
    name=”push_redis” server=”my-redis-server.example.com” serverport=”6379” type=”omhiredis” mode=”queue” key=”my_queue”)

Here’s an example redis-cli session where we RPOP from the queue:

::

  > redis-cli 127.0.0.1:6379> RPOP my_queue

  “<46>2015-09-17T10:54:50.080252-04:00 myhost rsyslogd: [origin software=”rsyslogd” swVersion=”8.13.0.master” x-pid=”6452” x-info=”http://www.rsyslog.com”] start”

  127.0.0.1:6379>

Mode: publish

In “publish” mode, the syslog message is published to a Redis topic set by “key”. If a template is not supplied, the plugin will default to the RSYSLOG_ForwardFormat template.

::

  module(load=”omhiredis”)

  action(
    name=”publish_redis” server=”my-redis-server.example.com” serverport=”6379” type=”omhiredis” mode=”publish” key=”my_channel”)

Here’s an example redis-cli session where we SUBSCRIBE to the topic:

::

  > redis-cli

  127.0.0.1:6379> subscribe my_channel

  Reading messages… (press Ctrl-C to quit)

  1. “subscribe”
  2. “my_channel”
  3. (integer) 1
  1. “message”
  2. “my_channel”
  3. “<46>2015-09-17T10:55:44.486416-04:00 myhost rsyslogd-pstats: {“name”:”imuxsock”,”origin”:”imuxsock”,”submitted”:0,”ratelimit.discarded”:0,”ratelimit.numratelimiters”:0}”