The Nginx Config Validator Runbook skill automates the validation and security analysis of Nginx web server configurations. It executes nginx -t for syntax validation and configuration file parsing verification before applying changes. The crossplane Python library provides programmatic parsing of Nginx configuration files into structured AST representations, enabling directive-level analysis across included files and upstream definitions. The gixy security analyzer scans configurations for common vulnerabilities including SSRF via proxy_pass misconfigurations, HTTP splitting through improper header handling, and path traversal in alias directives. The runbook validates SSL/TLS configurations checking certificate chain completeness, cipher suite strength against Mozilla recommended profiles, and OCSP stapling configuration. Performance analysis covers worker_processes optimization based on CPU cores, connection and buffer sizing, keepalive timeout tuning, and gzip compression settings. Rate limiting configurations are validated for proper zone sizing, burst allowances, and status code handling. The skill checks location block ordering for precedence issues, validates regular expression correctness in location directives, and detects conflicting server_name declarations across virtual hosts. Upstream health check configurations are verified for appropriate fail_timeout, max_fails, and backup server designations. Output includes a prioritized findings report with severity levels, specific line references, and corrective configuration snippets.