staymux

staymux keeps your tmux sessions alive by launching the server inside a user-scoped systemd slice and enabling linger automatically. It is designed for secure, compliance-bound environments where idle shells are terminated aggressively, yet administrators still need reliable, long-lived terminal workflows.

Why This Matters in STIGed Environments

DoD STIG guidance for Red Hat Enterprise Linux 8.7 and later (for example, RHEL-08-020035, also referenced as V-257258 / SV-257258r1069328) mandates that inactive interactive sessions be closed after ten minutes:

"Configure RHEL 8 to log out idle sessions after 10 minutes... StopIdleSessionSec=600." (RHEL 8 STIG, Version 2 Release 4, 02 Jul 2025)

That policy is essential for limiting unattended access, but it also means a long-running task can drop midstream if the operator steps away. With staymux, an administrator can launch a Satellite upgrade or other extended maintenance, detach from tmux, log out, and keep working elsewhere. If an SSH session is terminated by the ten-minute idle timeout, the tmux session stays intact so the job continues safely in the background.

Requirements

• Operating System: Modern Linux distribution with systemd support
  • Ubuntu 18.04 LTS or later
  • RHEL/CentOS/Rocky/AlmaLinux 8.0 or later
• systemd: Version 230 or later (for reliable user scope support)
• tmux: Version 2.1 or later

Features

• Starts tmux in a dedicated scope (stmux-<user>.scope) and keeps it alive after logout.
• Enables linger for the current account on first run, so the user instance continues running out of band.
• Provides guard rails for root execution and nested tmux sessions.
• Automatic OS and dependency version checking on startup.
• Friendly helper output, including usage examples and primary key bindings.

Quick Start

1. Copy staymux into a directory on your $PATH, e.g. /usr/local/bin/staymux.
2. Ensure it is executable: chmod 755 /usr/local/bin/staymux.
3. Run staymux once. If necessary, it will prompt you to enable linger (loginctl enable-linger $USER).
4. Disconnect from SSH or close your terminal; reconnect later and reattach with staymux <session>.

Usage

staymux                # attach to the single active session or create one named after the host
staymux dev            # attach to (or create) a session named "dev"
staymux -l             # list sessions managed by the tmux server
staymux -k <session>   # kill a specific session
staymux -k all         # tear down the tmux server and scope entirely

If you run into a compliance lockout or an SSH idle timeout, re-run staymux and you can continue where you left off.

Long Operations & Maintenance Windows

During activities such as:

• Red Hat Satellite upgrades that take hours to complete
• Bulk content deployments or long Ansible runs

staymux provides an anchored session that survives the idle timeout requirement. Administrators can step away, let cron jobs run, or reconnect after maintenance windows without losing state.

Development Notes

• The script automatically checks OS and dependency versions on startup and will warn about unsupported configurations.
• Contributions are welcome via pull request.

Version Support Notes

• Minimum requirements set to Ubuntu 18.04 LTS and RHEL 8
• Earlier versions may work but are not supported or tested

License

This project is licensed under the MIT License - see the LICENSE file for details.