Decisionengine Redis broker

Before getting started with Redis, please read https://redis.io/topics/security.

To keep Redis deployment consistent, we are recommending use of the official Redis container (https://hub.docker.com/_/redis).

If you are intending to run Redis on a shared network, review the container instructions for setting passwords.

For the most simple instance, on the DE Server, run:

podman run --name decisionengine-redis -p 127.0.0.1:6379:6379 -d redis:6 --loglevel warning

It should now be available at redis://127.0.0.1:6379/

Persistent storage is not currently required for our usage.

Note

You may need to install podman from your system repositories; it should ship with a lot of modern Linux distributions. The podman package should be compatible with Docker, in most cases either one can be used without issue. If podman is not available for your platform, you can review the Docker Desktop terms and conditions to see if you qualify for free usage.

Note

You may need to install nf-tables and remove ip-tables since Alma9 kernels support the former and not the letter. If you see an error like::

Error: netavark: code: 3, msg: modprobe: FATAL: Module ip_tables not found in directory /lib/modules/5.14.0-503.21.1.el9_5.x86_64 iptables v1.8.10 (legacy): can’t initialize iptables table `nat’: Table does not exist (do you need to insmod?) Perhaps iptables or your kernel needs to be upgraded.

Then Run the commands:

dnf rm iptables-legacy
dnf install iptables-nft

Configuring the DE server

By default, the decisionengine server will use a local redis instance and the default database there. However, it is preferable to set this specifically within the config so it is explicit.

decision_engine.jsonnet:

{
  broker_url: "redis://localhost:6379/0"
}

This is equivalent to the default, but provides a clear pointer within the config file to the exact location of redis.

Reviewing the Redis content

The redis-cli command is the official tool for looking at the content of a Redis data store.