Redis Key Exporter (RedisKey)

RedisKey is a lightweight Prometheus exporter that exposes numerical Redis key values (via GET key) or the number of items in the Redis list key (via LLEN key) as metrics. It connects to Redis using either a standalone host or Redis Sentinel and periodically refreshes metrics at a configurable interval.

Each Redis key you specify becomes a Prometheus gauge metric, and the exporter also provides an internal error counter to help monitor failures when fetching or parsing Redis values.

Requirements

- Go >= 1.25.4

Installation

$ git clone https://github.com/flant/rediskey.git
$ cd rediskey
$ go build cmd/rediskey/main.go
$ sudo install -m 755 main /usr/local/bin/rediskey

Configuration

RedisKey is configured entirely through environment variables. Below is the full list of supported variables:

Variable	Required	Default	Description
RKE_LISTEN_ADDRESS	No	0.0.0.0:8080	Address and port where RedisKey listens.
RKE_REDIS_DB	No	0	Redis database number to connect to.
RKE_REDIS_KEYS_GET	No	none	Comma-separated list of Redis keys to monitor via GET. Only keys with a numerical value are supported.
RKE_REDIS_KEYS_LLEN	No	none	Comma-separated list of Redis keys to monitor via LLEN.
RKE_REDIS_HOST	No	none	Standalone Redis host and port in the format host:port. Ignored if sentinels are set.
RKE_REDIS_PASSWORD	No	none	Password for Redis authentication, if required.
RKE_REDIS_SENTINELS	No	none	Comma-separated list of Redis Sentinel addresses in the format host1:port,host2:port.
RKE_REDIS_MASTER_NAME	No	mymaster	Master name for Sentinel mode.
RKE_METRICS_PATH	No	/metrics	HTTP path where Prometheus metrics are exposed.
RKE_REFRESH_INTERVAL	No	10	Interval in seconds between metric refreshes from Redis.

Running RedisKey

1. Set required environment variables

These are the minimum variables needed to run RedisKey:

$ export RKE_REDIS_HOST="rfrm-redis:6379"
$ export RKE_REDIS_KEYS_GET="queue.message_id"
$ export RKE_REDIS_KEYS_LLEN="queue.waiting"

2. Start the exporter

$ rediskey
2025/11/28 19:11:57 Starting Redis Key Exporter...
2025/11/28 19:11:57 Listening on 0.0.0.0:8080/metrics