Captures the majorlab incident where the backup watchdog emailed a missing
heartbeat after a kernel-update reboot wiped /var/run, even though the
backup had actually completed cleanly. Documents the tmpfs root cause and
the fix of storing heartbeats under /var/lib instead.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Covers shell quoting for URLs containing &, ?, #, and other characters
that Bash interprets as operators. Common gotcha when downloading from
CDNs with token-based URLs.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Corrected inflated article count (was 76, actual is 73).
Updated domain breakdown and frontmatter timestamps from Obsidian.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Access-log-based filter for wp-login.php brute force detection without
requiring the WP fail2ban plugin. Documents the backend=polling gotcha
on Ubuntu 24.04 and manual banning workflow.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
New article: selinux-fail2ban-execmem-fix.md — custom policy module
for fail2ban grep execmem denial on Fedora 43.
Also includes previously uncommitted:
- n8n-proxy-trust-x-forwarded-for.md
- fail2ban-apache-404-scanner-jail.md updates
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Documents the N8N_PROXY_HOPS env var needed for n8n behind Caddy/Nginx
when N8N_TRUST_PROXY alone is insufficient in newer versions.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Covers version checking, pinned-tag update process, SQLite password
reset, and why Arcane may not catch updates when the latest tag lags
behind npm releases.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Documents the SSH keepalive fix for dnf upgrade timeouts on Fedora hosts,
plus the do-agent task guard fix. Also adds Ansible & Fleet Management
section to the troubleshooting index.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
New guide for custom access-log-based fail2ban jail that catches
rapid-fire 404 vulnerability scanners missed by default error-log jails.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Add troubleshooting article for the 2026-03-27 incident where PHP-FPM
hung after the nightly update cycle. Update the Netdata Docker alarm
tuning article with the dedicated Nextcloud alarm split and the new
watchdog cron deployed to majorlab. (54 articles)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Documents the 2026-03-14 incident where MajorAir's public IP was banned
by the postfix-sasl jail after repeated SASL auth failures, silently
blocking all IMAP connections from Spark Desktop.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Add troubleshooting article covering the three-part failure mode on
Fedora with SELinux Enforcing: docker.socket disabled, ports 4443/8448
blocked, and httpd_can_network_connect off. Update index and SUMMARY.
