bailiff

Sidecar for distributed session for microservices

Problem

When heaving deal with storing user's data between requests there are two basic variants how to do that:

• passing data in every request (JWT, raw values in Cookie header)
• storing data in some storage (files, memory, external db, etc) by some ID of session, with passing only this ID in request data

There are tons of articles on the internet with pros and cons of both variants, so we will not stop on this. The one thing that need to be said is that implementing session pattern in microservices environment could be quite tricky. So here comes bailiff.

Solution

Bailiff is a sidecar for your backend apps which takes the routine of saving and restoring session data. On every income request it checks if there is a session. If so bailiff enriches request by passing new headers with session data (see example below). Also, bailiff checks every response if there are any data to save or update in session.

All bailiff sidecars are connected with single storage, so all session data is shared between all microservices. So if microservice Foo saved userID in session, microservice Bar will get it in next request.

Please see example below:

Usage

As it was described before it should be run as sidecar for existing backends.

Docker image

Basic example is:

docker run \
    -e BAILIFF_STORE_REDIS_ADDR=redis:6379 \
    -e BAILIFF_PROXY=http://app \
    -e BAILIFF_COOKIE_MAXAGE=3600 \
    bailiff/bailiff:latest

You can find more complex example with multiple backends in examples folder.

Storages

Bailiff is built with support of different stores in mind but only redis storage is supported so far.

Configuration

TO DO...