sablierapp/sablier

Sablier is a container orchestration tool that starts workloads on demand and automatically stops them after periods of inactivity.

The tool solves the problem of resource waste from idle containers by intercepting incoming requests through reverse proxy plugins, waking sleeping workloads, and displaying a waiting page while they start. It works by integrating with reverse proxies like Traefik, Caddy, Nginx, Envoy, and others to detect traffic and trigger container lifecycle management across multiple platforms.

Sablier suits resource-constrained environments like Raspberry Pi deployments, infrequently-used QA environments, and cloud setups where scaling idle workloads to zero reduces costs. It supports Docker, Docker Swarm, Podman, Kubernetes, and Proxmox LXC, making it broadly compatible across container platforms. The tool offers customizable waiting UI themes, webhook notifications for start and stop events, Prometheus metrics, and OpenTelemetry tracing for observability. A scale mode allows throttling CPU and memory instead of stopping containers entirely, eliminating cold-start delays for latency-sensitive workloads. Anti-affinity features prevent resource contention by making workloads back off automatically when others are active.

The project maintains steady development with regular releases and active issue resolution. Contributions are accepted and encouraged through standard pull request workflows. Documentation is comprehensive, covering installation methods including Docker images, binary distributions, and Helm charts, alongside detailed configuration guides for each supported platform and reverse proxy integration.