On a fresh AlmaLinux 9.8 box, install_bruteforce_protection ran unguarded under
'set -euo pipefail'. When sshguard (from EPEL) wasn't installable at that moment,
the single failed dnf aborted the ENTIRE harden run before it wrote sshd_config
or installed the pam_exec login notifier -- leaving a stock, unhardened box and a
silently-missing ntfy hook.
- oslib: install the iptables backend best-effort first, then sshguard, and
return sshguard's status so callers can treat it as non-fatal.
- harden-ssh/harden-jumphost: install_openssh now dies with a clear message on
failure; sshguard is '|| warn' so sshd hardening and the notifier still apply.
- install_login_notifier verifies the script + pam hook landed and logs
'Login notifier ACTIVE' (or a loud warning) instead of failing silently.
- ntfy-ssh-login.sh: NTFY_DEBUG=1 logs delivery attempts + curl errors to
/var/log/ssh-notify.log so the next silent failure leaves a trace.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
57_WolveandClaude Opus 4.8
60433e4c8d