Valkey

This geneset contains fodder for installing a Valkey server on Linux. Valkey is the open-source, Redis-compatible (RESP) in-memory data store.

The RHEL family no longer packages Redis, so this gene standardises on Valkey, which both Linux families provide. Clients and libraries that speak the Redis protocol work against it.

The fodder is cross-platform across Linux families. It works on Debian/Ubuntu and on the RHEL family (AlmaLinux, Rocky Linux, ...). It has been tested on Debian 13 and AlmaLinux 10.

Usage

Add a gene reference to a Linux catlet, give it a data drive for its persistent state (see Persistent state), and optionally set a password:

name: valkey-server
parent: dbosoft/debian-13/starter

drives:
 - name: sdb
   size: 10
   location: valkey-data

fodder:
 - source: gene:dbosoft/valkey:server
   variables:
     - name: password
       value: change-me-please
       secret: true

A typical use is a cache or session store for an application, for example a nextcloud or wordpress catlet, which connects to this host on port 6379.

The fodder:

• installs Valkey (valkey-server on Debian/Ubuntu, valkey on the RHEL family) and starts it
• listens on all interfaces (bind 0.0.0.0, protected-mode no)
• sets requirepass when a password is given
• sets maxmemory and the allkeys-lru eviction policy when a memory limit is given
• mounts the state drive at /var/lib/valkey so the saved data survives a redeploy
• opens port 6379/tcp when firewalld or ufw is active

Persistent state

Valkey periodically saves its data to disk (an RDB snapshot in its data directory). That data would be lost on a redeploy, because the OS disk is recreated from the gene. Give the catlet a second drive and make it persistent with an explicit location. This is the key detail: name (sdb) only sets the device order inside the guest, while location is the drive's identity on the host. Without a location, eryph assigns a throwaway storage id and deletes the drive together with the catlet; with one, the drive lives independently of the catlet and is re-attached on the next deploy. Pick a location that is unique within the project (the example uses valkey-data).

The fodder formats the drive on first use (ext4, label valkey) and mounts it at the data directory /var/lib/valkey, so the saved data survives a redeploy (removing the catlet and deploying it again with the same location). If no empty drive is present, provisioning stops with a clear error.

A pure in-memory cache does not strictly need this, but these genes are reference setups and default to durable state. For a throwaway cache you can still point an app at it and ignore the saved data.

Configuration

The following variables can be used to configure the server fodder:

• password
  optional, secret, default value: empty

  The authentication password (requirepass). Strongly recommended whenever the server is reachable from other hosts, as it listens on all interfaces. An empty value means no authentication.

• maxmemory
  optional, default value: empty

  A memory limit such as 256mb or 2gb. When set, the eviction policy allkeys-lru is enabled. An empty value means no limit.

Security

The server listens on all interfaces with protected mode off so that other catlets can reach it. For anything beyond a trusted internal network, set a password and restrict network access.

Versioning

This geneset contains only fodder genes and is versioned with a major-minor version scheme.

There is no patch version - when a bug is fixed, a new minor version will be released.
A new major version is released when a gene is removed from the geneset.

The tag latest is updated with each released version. If you want to have a stable reference, don't use the latest tag, use a specific version tag.

Contributing

This geneset is maintained by dbosoft and is open for contributions.

You can find the repository for this geneset on github.com/dbosoft/eryph-genes.

License

All public dbosoft genesets are licensed under the MIT License.