HAProxy Redis Sentinel

Python pub/sub based Sentinel master change notifier that updates HAProxy using it's Runtime API

Just create a simple HAProxy config and it will handle everything for you

global
  stats socket /var/run/haproxy/haproxy.sock user haproxy group haproxy mode 660 level admin
  stats timeout 2m

frontend redis_master
    bind *:6379
    default_backend redis_master

backend redis_master
    balance source
    hash-type consistent

Is enough

To run this project install poetry (and run poetry install) or use direnv that handles automatic installation of requirements and the project itself

Usage

poetry run haproxy-redis-sentinel is our command entrypoint

Sentinel Info

• --sentinel-host -h TEXT
  Sentinel Hostname
  [env var: SENTINEL_HOST]
  [default: 127.0.0.1]

• --sentinel-port -p INTEGER
  Sentinel Port
  [env var: SENTINEL_PORT]
  [default: 26379]

• --sentinel-password -P TEXT
  Sentinel Password
  [env var: SENTINEL_PASSWORD]
  [default: None]

• --master-name -m TEXT
  Sentinel Master name
  [env var: MASTER_NAME]
  [default: mymaster]

HAProxy Info

• --haproxy-socket TEXT
  HAProxy admin socket address
  [env var: HAPROXY_SOCKET]
  [default: /var/run/haproxy/haproxy.sock]

• --haproxy-backend TEXT
  HAProxy Backend name to control (Set it to an empty backend)
  [env var: HAPROXY_BACKEND]
  [default: redis_master]

• --haproxy-server-name TEXT
  HAProxy Server name to control, It will be added and controlled through the given backend
  [env var: HAPROXY_SERVER_NAME]
  [default: current_master]

In Containers

compose.yaml file is present is project root

Set/Change env vars and run it or add this project as a service to your existing setup

You need HAProxy in a seperated Container/Server

K8s

helm repo add haproxy-redis-sentinel https://parmincloud.github.io/haproxy-redis-sentinel/
helm repo update

Create a file names values.yaml and customize values (according to defualt values)

helm install haproxy-redis-sentinel haproxy-redis-sentinel/haproxy-redis-sentinel --values ./values.yaml

Why?

HAProxy is a great TCP Proxy and LoadBalancer with high performance

But It's not able be live in master changes, Using Runtime API we are able to configure that programmatically

Unlike similar projects that they wrote a TCP Proxy from zero, We don't want to write Wheel from zero we are using the Power of HAProxy :)

With the help of Redis Pub/Sub we are able to understand master changes live that propagate changes to HAProxy By disconnecting all of the connections and changing server address accordingly

TODO

• Add error handling for HAProxy commands
• Add probes to K8s Chart