Free and open-source software that starts workloads on demand and stops them after a period of inactivity.

It integrates with reverse proxy plugins (Traefik, Caddy, Nginx, Envoy, etc.) to intercept incoming requests, wake up sleeping workloads, and display a waiting page until they're ready.

Whether you don't want to overload your Raspberry Pi, or your QA environment is used only once a week and wastes resources by keeping workloads running, Sablier might be the solution you need.

• Installation
  • Use the Docker image
  • Use the binary distribution
  • Compile your binary from the sources
  • Use the Helm Chart
• Quick Start
• Configuration
  • Configuration File
  • Environment Variables
  • Arguments
• Providers
  • Docker
  • Docker Swarm
  • Podman
  • Kubernetes
• Usage with Reverse Proxies
  • Apache APISIX
  • Caddy
  • Envoy
  • Istio
  • Nginx
  • Traefik
• Community
• Support
• Sponsor
  • DigitalOcean

Installation

You can install Sablier using one of the following methods:

• Use the Docker image
• Use the binary distribution
• Compile your binary from the sources
• Use the Helm Chart

Use the Docker image

• Docker Hub: sablierapp/sablier
• GitHub Container Registry: ghcr.io/sablierapp/sablier

Choose one of the Docker images and run it with a sample configuration file:

• sablier.yaml

docker run -p 10000:10000 -v /var/run/docker.sock:/var/run/docker.sock sablierapp/sablier:1.10.5

Tip

Verify the image signature to ensure authenticity:

gh attestation verify --owner sablierapp oci://sablierapp/sablier:1.10.5

Use the binary distribution

Grab the latest binary from the releases page and run it:

./sablier --help

Tip

Verify the binary signature to ensure authenticity:

gh attestation verify sablier-1.10.3-linux-amd64.tar.gz -R sablierapp/sablier

Compile your binary from the sources

git clone [email protected]:sablierapp/sablier.git
cd sablier
make
# Output will change depending on your distro
./sablier_draft_linux-amd64

Use the Helm Chart

Deploy Sablier to your Kubernetes cluster using the official Helm chart for production-ready deployments.

Add the Sablier Helm repository:

helm repo add sablierapp https://sablierapp.github.io/helm-charts
helm repo update

Install Sablier:

helm install sablier sablierapp/sablier

📚 Full Documentation | 💻 Chart Repository

---

Quick Start

Note

This quick start demonstrates Sablier with the Docker provider.

For other providers, see the Providers section.

1. Start your container to scale to zero

Run your container with Sablier labels:

docker run -d --health-cmd "/mimic healthcheck" -p 8080:80 --name mimic \
  --label sablier.enable=true \
  --label sablier.group=demo \
  sablierapp/mimic:v0.3.2 \
  -running -running-after=5s \
  -healthy=true -healthy-after=5s

Here we run sablierapp/mimic, a configurable web-server for testing purposes.

Caution

You should always use a healthcheck with your application that needs to be scaled to zero.

Without a healtheck, Sablier cannot distinguish a started container from a container ready to receive incoming requests.

2. Stop the Container

Stop the container to simulate a scaled-down state:

docker stop mimic

Tip

Sablier can automatically stop containers at startup using the --provider.auto-stop-on-startup flag, which will stop all containers with sablier.enable=true labels.

3. Start Sablier

Start the Sablier server with the Docker provider:

docker run --name sablier \
  -p 10000:10000 \
  -v /var/run/docker.sock:/var/run/docker.sock \
  sablierapp/sablier:1.10.5 \
  start --provider.name=docker

4. Request a Session

Call the Sablier API to start a session for the demo group:

curl -v http://localhost:10000/api/strategies/blocking\?group\=demo\&session_duration\=20s
* Request completely sent off
< HTTP/1.1 200 OK
< X-Sablier-Session-Status: ready

Sablier will start the mimic container automatically for 20 seconds..

Tip

Check out the Usage with Reverse Proxies section to integrate Sablier with Traefik, Caddy, Nginx, and more.

5. Verify the Container is Running

docker ps | grep mimic

6. Wait for Session Expiration

After the session duration (20 seconds in this example), Sablier will automatically stop the container.

# Wait 20 seconds, then check
docker ps -a | grep mimic

The container should be stopped.

---

Configuration

There are three ways to configure Sablier:

1. In a configuration file
2. As environment variables
3. As command-line arguments

Configuration sources are evaluated in the order listed above.

If no value is provided for a given option, a default value is used.

Configuration File

At startup, Sablier searches for a configuration file named sablier.yml (or sablier.yaml) in:

• /etc/sablier/
• $XDG_CONFIG_HOME/
• $HOME/.config/
• . (the working directory)

You can override this using the configFile argument.

sablier --configFile=path/to/myconfigfile.yml

provider:
  # Provider to use to manage containers (docker, swarm, kubernetes)
  name: docker 
server:
  # The server port to use
  port: 10000 
  # The base path for the API
  base-path: /
storage:
  # File path to save the state (default stateless)
  file:
sessions:
  # The default session duration (default 5m)
  default-duration: 5m
  # The expiration checking interval. 
  # Higher duration gives less stress on CPU. 
  # If you only use sessions of 1h, setting this to 5m is a good trade-off.
  expiration-interval: 20s
logging:
  level: debug
strategy:
  dynamic:
    # Custom themes folder, will load all .html files recursively (default empty)
    custom-themes-path:
    # Show instances details by default in waiting UI
    show-details-by-default: false
    # Default theme used for dynamic strategy (default "hacker-terminal")
    default-theme: hacker-terminal
    # Default refresh frequency in the HTML page for dynamic strategy
    default-refresh-frequency: 5s
  blocking:
    # Default timeout used for blocking strategy (default 1m)
    default-timeout: 1m

Environment Variables

Environment variables follow the same structure as the configuration file. For example:

strategy:
  dynamic:
    custom-themes-path: /my/path

becomes

STRATEGY_DYNAMIC_CUSTOM_THEMES_PATH=/my/path

Arguments

To list all available arguments:

sablier --help

# or

docker run sablierapp/sablier:1.10.4 --help

Command-line arguments follow the same structure as the configuration file. For example:

strategy:
  dynamic:
    custom-themes-path: /my/path

becomes

sablier start --strategy.dynamic.custom-themes-path /my/path

Providers

Docker

Sablier integrates seamlessly with Docker Engine to manage container lifecycle based on demand.

Features:

• Connects to the Docker socket
• Starts/Stops containers
• Compatible with Docker Compose

📚 Full Documentation

---

Docker Swarm

Sablier supports Docker Swarm mode for managing services across a cluster of Docker engines.

Features:

• Connects to the Docker socket (Manager node)
• Scales services to 0 and back
• Compatible with Docker Stack

📚 Full Documentation

---

Podman

Sablier works with Podman, the daemonless container engine, providing the same dynamic scaling capabilities as Docker.

Features:

• Connects to the Podman socket
• Starts/Stops containers
• Supports rootless containers

📚 Full Documentation

---

Kubernetes

Sablier provides native Kubernetes support for managing deployments, scaling workloads dynamically.

Features:

• Connects to the Kubernetes API
• Scales Deployments and StatefulSets to 0 and back
• Supports in-cluster and out-of-cluster configuration

📚 Full Documentation

Usage with Reverse Proxies

Sablier is an API server that manages workload lifecycle. To automatically wake up workloads when users access your services, you can integrate Sablier with reverse proxy plugins.

These plugins intercept incoming requests, call the Sablier API to start sleeping workloads, and display a waiting page until they're ready.

Apache APISIX

Sablier integrates with Apache APISIX through a Proxy-WASM plugin, enabling dynamic scaling for your services.

Quick Start:

1. Install the Sablier Proxy-WASM plugin
2. Configure APISIX routes with Sablier plugin settings
3. Define your scaling labels on target services

📚 Full Documentation | 💻 Plugin Repository

---

Caddy

Sablier provides a native Caddy module for seamless integration with Caddy v2.

Quick Start:

1. Build Caddy with the Sablier module using xcaddy
2. Add Sablier directives to your Caddyfile
3. Configure dynamic scaling rules

📚 Full Documentation | 💻 Plugin Repository

---

Envoy

Sablier integrates with Envoy Proxy through a Proxy-WASM plugin for high-performance dynamic scaling.

Quick Start:

1. Deploy the Sablier Proxy-WASM plugin
2. Configure Envoy HTTP filters
3. Set up scaling labels on your workloads

📚 Full Documentation | 💻 Plugin Repository

---

Istio

Sablier works with Istio service mesh using the Proxy-WASM plugin for intelligent traffic management.

Quick Start:

1. Install the Sablier Proxy-WASM plugin in your Istio mesh
2. Configure EnvoyFilter resources
3. Annotate your services with Sablier labels

📚 Full Documentation | 💻 Plugin Repository

---

Nginx

Sablier integrates with Nginx through a WASM module, bringing dynamic scaling to your Nginx deployments.

Quick Start:

1. Build Nginx with WASM support
2. Load the Sablier Proxy-WASM plugin
3. Configure Nginx locations with Sablier directives

📚 Full Documentation | 💻 Plugin Repository

---

Traefik

Sablier provides a powerful middleware plugin for Traefik, the cloud-native application proxy.

Quick Start:

1. Add the Sablier plugin to your Traefik static configuration
2. Create Sablier middleware in your dynamic configuration
3. Apply the middleware to your routes

📚 Full Documentation | 💻 Plugin Repository

Community

Join our Discord server to discuss and get support!

Support

This project is maintained by a single developer in their free time. If you find Sablier useful, here are some ways you can show your support:

⭐ Star the repository - It helps others discover the project and motivates continued development

🤝 Contribute - Pull requests are always welcome! Whether it's:

• Bug fixes
• New features
• Documentation improvements
• Test coverage

📚 Share your usage - We'd love to see how you're using Sablier! Consider:

• Opening a discussion to share your setup
• Contributing examples of your deployment configurations
• Writing a blog post or tutorial

💬 Engage with the community - Ask questions, report issues, or help others in discussions

Every contribution, no matter how small, makes a difference and is greatly appreciated! 🙏

For detailed support options, see SUPPORT.md.

Sponsor

If you find Sablier valuable and want to support its development, please consider sponsoring the project:

💖 Sponsor on GitHub - Your sponsorship helps keep this project maintained and actively developed

Your support helps:

• Keep the project maintained and up-to-date
• Dedicate more time to bug fixes and new features
• Improve documentation and examples
• Support the broader open-source ecosystem

Every contribution, no matter the size, makes a real difference. Thank you for considering! 🙏

DigitalOcean

This project is supported by: