Major update to SPEC-012 adding dual-mode terminal access:
Mode 1: Serial Console Mode (True Remote Console)
- Direct access to system serial console (/dev/ttyS0 or /dev/console)
- Sees GRUB bootloader, kernel boot messages, login prompts, kernel panics
- Boot-time interaction: select GRUB entries, edit kernel parameters, single-user mode
- Requires root privileges or CAP_SYS_TTY_CONFIG capability
- Setup: GRUB + kernel parameters configured for serial console output
- Like KVM-over-IP or IPMI Serial-over-LAN (text-mode equivalent)
Mode 2: PTY Shell Mode (Interactive Shell)
- Spawn pseudo-TTY with bash/zsh shell session
- Normal server management (package updates, log review, etc.)
- Runs as unprivileged agent service user
- Standard interactive shell with full ANSI/VT100 support
Architecture:
- Agent mode selection based on viewer request (console vs. shell)
- Dashboard shows two buttons: "Console" and "Shell" for headless agents
- Same xterm.js viewer handles both modes transparently
- Protobuf extensions: TerminalModeRequest enum, console_mode flag
Security:
- Console mode requires root (boot-level control risk)
- Recommend RBAC: separate console_access and shell_access permissions
- Console sessions should require MFA (Phase 2)
- Audit logging for both modes
Setup Requirements:
- One-time GRUB configuration for serial console
- systemd service with CAP_SYS_TTY_CONFIG for console mode
- serial-getty@ttyS0.service enabled for login prompt
Updated effort: Medium (5-7 weeks, up from 4-6)
Priority remains P2
Addresses user request for "remote console" (as if at the machine)
not just shell access.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>