postgredis

postgredis

A wild idea of having Redis-compatible server with PostgreSQL backend.

Getting started

As a binary:

./postgredis -addr=:6380 -db=postgres://postgres:postgres@localhost:5432/postgredis -table=postgredis

As a docker container:

docker run -it postgredis:latest -addr=:6380 -db=postgres://postgres:postgres@db:5432/postgredis -table=postgredis

Note: it was intended to run inside docker network with postgres in a container on the same network, see docker-compose.yml

You can use redis-cli and play around with supported commands (see below):

> redis-cli -p 6380
127.0.0.1:6380> set x 123
OK
127.0.0.1:6380> set x 1
OK
127.0.0.1:6380> get x
"1"

or connect with various redis-compatible libraries (see example/example.go).

Why

I like how Redis interface works. It is easy to understand and you can bootstrap new projects quickly without dealing with persistant storage. I also don't have to deal with migrations management and sql-related libraries. But Redis itself is not good as a persistent storage.

I like PostgreSQL, it is my goto database. I have a couple of web services using it at the moment. And I try to stick with PostgreSQL when any of the self-hosted appliances provide it as a storage choice.

I've been using bitcask a lot recently, and I liked how you can start bitcask server and use libraries like redigo to interact with the server. I then found out that writing Redis interfaces for any storage backend is quite easy with redcon library. I even looked at solutions like LedisDB, but it seemed unmaintained and too bloated for my use cases.

So I decided to implement PostgreSQL backend for Redis' interface.

How it works

When you first start postgredis, it will create a table with two columns: unique key and value. They both are in text format. Unique key helps with concise "upsert" queries. Thanks to pgx I don't have think about how to maintain a connection, I just start a pool. There is also a logging of sql queries, which is good for debugging.

Supported commands

See COMMANDS.md.

Future plans

• make use of query args from the redis connection uri to specify table - http://www.iana.org/assignments/uri-schemes/prov/redis
• implement pub/sub mechanizms
• implement other data types, ex. sets
• implement scan
• add ttl handling
• indexing and other query optimizations

Disclaimer

This is an MIT licensed code, which uses open sourced software. The name of the package is a work-in-progress and I am willing to change it. PostgreSQL and Redis are registered names and I am not affiliated with them.