safe-cron-runner

What This Skill Does

The Safe Cron Runner is a specialized execution wrapper designed to mitigate the inherent risks associated with autonomous agent background tasks. When an AI agent needs to perform system operations, it is often necessary to run subprocesses. This skill provides a hardened container for these tasks by automatically enforcing principle-of-least-privilege through user switching, strict execution time limits, and non-shell command invocation. By utilizing ISNAD-signed manifests, the skill ensures that the underlying logic remains tamper-proof, providing developers with a robust mechanism for scheduling and running recurring operations without exposing the host environment to elevated risk. The tool abstracts the complexity of process management and security hardening into a simple, list-based interface that developers can integrate into their existing agent workflows.

Installation

To integrate this skill into your OpenClaw agent, use the command-line interface to pull the module from the central repository:

clawhub install openclaw/skills/skills/horn111/safe-cron-runner

Once installed, you can import the SafeCronRunner class into your Python agent scripts and initialize it with your desired security parameters, such as the target safe_user and timeout_sec configuration.

Use Cases

This skill is ideal for agents tasked with:

• Periodic log cleanup or system maintenance scripts.
• Running data processing pipelines that shouldn't have root access.
• Executing generated scripts from untrusted external sources where containment is required.
• Monitoring system health indicators without needing full system administration privileges.

Example Prompts

1. "Run the system cleanup script /usr/local/bin/cleanup.sh, but ensure it is limited to a 30-second runtime and executed as the nobody user."
2. "Execute the command to generate a daily report from our logs, but keep the execution isolated and safe from shell injection."
3. "Start a background task that periodically verifies file permissions in /var/log, ensuring the process is dropped to non-root privileges immediately."

Tips & Limitations

The Safe Cron Runner relies on the underlying system's ability to switch users; therefore, the agent must be running with permissions sufficient to initiate a su or setuid call. It does not provide network isolation, only command-level execution security. Always ensure that the user specified in safe_user has the minimum required permissions to read and write to the necessary directories for your specific tasks.