I know that it is possible to pass your own config file but I'd rather edit the handful of values I care about in the default config. I'm having a hard time finding a default redis.conf anywhere though, do I just have to COPY my own into the container?
The default image from redis does not have a redis.conf.
Here is the link for the image on dockerhub. https://hub.docker.com/_/redis/
You will have to copy it to image or have it mapped on the host using a volume mapping.