liveness

Liveness Checks Made Easy

When working in a Kubernetes environment you should be defining meaningful readinessProbes and livenessProbes. However, most teams implement a simple /healthz endpoint which only confirms that the server is ready to serve requests. This is not a great indicator of "liveness" as there are often dependencies which need to be alive and reachable as well such as a database. If you already include a DB connection attempt and cache ping in your /healthz endpoint then this tool isn't for you. But if you're looking for a quick way to add meaningful liveness to your kubernetes pods then read on.

liveness is a simple process which you can run either inside your Docker container as a background process or as a sidecar container. It takes a list of resources via command line flags which it will monitor for liveness. It runs an HTTP server that whenever it receives a request to any URL it will check all the provided resources to ensure they are still accepting connections. If any resource has become unavailable it will respond with a 503 Server Unavailable response otherwise, it will send a 200.

In this way you don't need to reinvent the wheel if you're just looking for simple liveness. It also is very useful for long running services which aren't HTTP server likes background workers (such as those provided by Celery) since it can add that functionality to check all the relevant dependencies are still alive.

Installation

Usage

Supported Check Types

Examples