20Container

20Container is a lightweight container management framework designed to deploy and manage up to 20 isolated containers on a single host or small cluster. It targets developers and operations teams seeking a predictable, low-overhead approach to running a fixed set of services, without the complexity of large-scale orchestrators. The project emphasizes simplicity, fast startup, and deterministic resource usage.

The system uses existing container runtimes such as Docker or containerd and relies on a declarative configuration file named 20container.yaml (or 20c.yaml) to describe the desired state. Each entry defines an image, an execution command, resource limits, networking, and volume mounts. The configuration is designed to be human-readable and easy to version with source control.

Core components include the 20Container daemon (20d), which runs on the host, and the 20ctl command-line interface for user interaction. A modular scheduler assigns containers to a fixed set of slots and monitors health, restarts failed containers, and ensures isolation through namespaces and cgroups.

Networking is implemented via a lightweight bridge with predefined IP ranges, while storage uses bind mounts or named volumes. The system provides basic health checks, logs aggregation, and simple metrics suitable for small deployments.

Usage is designed for small-scale deployments. After writing a 20container.yaml, users run 20ctl deploy to start all containers, 20ctl status to verify operation, and 20ctl update or 20ctl scale to modify the configuration within the 20-container limit.