Handles k8s liveness and readiness probes. Use as the first plug in endpoint.ex.

• GET /probe/liveness → 200 while the BEAM is running.
• GET /probe/readiness → 200 when KubernetesProbes.Drainer is :running and the optional ready? function returns true; 503 otherwise.

Usage

# lib/my_app_web/endpoint.ex — before all other plugs
plug KubernetesProbes.Plug

# With a custom readiness check (e.g. database connectivity)
plug KubernetesProbes.Plug, ready?: &MyApp.repos_ready?/0

# With custom probe paths
plug KubernetesProbes.Plug, liveness_path: "/healthz", readiness_path: "/readyz"

Options

• :ready? — zero-arity boolean function called on each readiness request while the drainer is :running. Must be a remote function capture (&MyApp.repos_ready?/0), not an anonymous function. Defaults to &KubernetesProbes.Plug.always_ready/0 (always returns true).
• :liveness_path — path for the liveness probe. Defaults to "/probe/liveness".
• :readiness_path — path for the readiness probe. Defaults to "/probe/readiness".