keepalive

Pluggable Go daemon that periodically touches external services to prevent idle shutdowns, pauses, or cold starts.

The current adapters perform cheap datastore writes for Redis Cloud, Valkey, Aiven, Neon, Supabase, MongoDB Atlas, Couchbase Capella, and similar hosted services.

Successor to the *-keepalive family: one binary, one image, six datastore adapters.

Supported adapters

Set KEEPALIVE_ADAPTER to one of the values below.

`KEEPALIVE_ADAPTER`	Driver	Env vars
`redis`	`github.com/redis/go-redis/v9`	`KEEPALIVE_REDIS_URL`
`valkey`	`github.com/valkey-io/valkey-go`	`KEEPALIVE_VALKEY_URL`
`postgresql`	`github.com/lib/pq`	`KEEPALIVE_POSTGRESQL_URL`
`mysql`	`github.com/go-sql-driver/mysql`	`KEEPALIVE_MYSQL_DSN`
`mongodb`	`go.mongodb.org/mongo-driver/v2`	`KEEPALIVE_MONGODB_URI`, `KEEPALIVE_MONGODB_DATABASE`, `KEEPALIVE_MONGODB_COLLECTION`
`couchbase`	`github.com/couchbase/gocb/v2`	`KEEPALIVE_COUCHBASE_CONNECTION_STRING`, `KEEPALIVE_COUCHBASE_USERNAME`, `KEEPALIVE_COUCHBASE_PASSWORD`, `KEEPALIVE_COUCHBASE_BUCKET_NAME`, `KEEPALIVE_COUCHBASE_SCOPE_NAME`, `KEEPALIVE_COUCHBASE_COLLECTION_NAME`

Optional: KEEPALIVE_INTERVAL (e.g. 30s, 5m; default 1m), KEEPALIVE_COUNTER_KEY (default counter).

Quick start (Docker)

docker run -d --name keepalive --restart unless-stopped \
  -e KEEPALIVE_ADAPTER=redis \
  -e KEEPALIVE_REDIS_URL='redis://default@host:6379' \
  ghcr.io/tiennm99/keepalive:latest

Quick start (local)

git clone https://github.com/tiennm99/keepalive
cd keepalive
cp .env.example .env       # then edit KEEPALIVE_ADAPTER + the driver's env vars
go run .

How it works

On every tick the chosen adapter performs the cheapest write that proves the cluster is alive. KEEPALIVE_COUNTER_KEY selects the key/doc ID and defaults to counter.

Redis/Valkey — INCR key
PostgreSQL — UPDATE keepalive SET value = value + 1 WHERE key = $1 RETURNING value
MySQL — UPDATE + SELECT by key inside a transaction
MongoDB — FindOneAndUpdate({_id: key}, {$inc: {count: 1}}, upsert)
Couchbase — GET key -> ++ -> UPSERT key

The PostgreSQL and MySQL adapters expect a table:

CREATE TABLE keepalive (key TEXT PRIMARY KEY, value BIGINT NOT NULL DEFAULT 0);
INSERT INTO keepalive (key, value) VALUES ('counter', 0);

Seed the value with your configured KEEPALIVE_COUNTER_KEY when it is not counter. MySQL uses backticked identifiers — see adapter/mysql.go.

Adding a new adapter

Create adapter/<name>.go.
Implement the Adapter interface in adapter/adapter.go (Connect, Increment, Close).

func init() { Registry["<name>"] = func() (Adapter, error) { return &myAdapter{}, nil } }

Add an import _ "your driver" if needed, and the KEEPALIVE_* env vars to .env.example and the table above.

Migrated from

This repo replaces six single-datastore repos. All are archived with a pointer here:

License

Apache-2.0 — see LICENSE.

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