Hardened NATS on CentOS Stream 9

This is a repackaged open source software product wherein additional charges apply for a pre-hardened, AWS-optimized image with verifiable compliance evidence and maintenance. NATS Server runs on a CentOS Stream 9 base hardened following DISA STIG guidelines, tuned for Amazon EC2 workloads, and shipped with a complete OpenSCAP evidence pack and Software Bill of Materials (SBOM).

NATS Server Deployment:

1. Best-Practice Deployment: NATS Server is configured to start automatically on boot via systemd, ready to route messages on first launch.

2. Built-In Monitoring: The HTTP monitoring interface on port 8222 gives immediate visibility into server health, connection metrics, and subscription statistics.

3. Bloat-Free Messaging Layer: CPU and memory go to the server, its JetStream persistence layer, and message routing rather than unused system services.

Hardened Operating System Base:

1. DISA STIG Alignment: 334 security controls applied to the CentOS Stream 9 base via the SCAP Security Guide, including auditd logging, SSH hardening, kernel command line and module blocklist restrictions, and strict password policy enforcement.

2. Fully Patched at Release: Zero packages with a pending update at build time, verified. The complete CVE scan ships inside the image.

3. Documented Exceptions: Every STIG rule not applied is itemized with a technical justification, so the delivered posture is auditable.

Comprehensive Evidence Pack:

Every AMI carries an OpenSCAP evidence pack generated against DISA STIG guidance, under /opt/hardening-report/:

• Base_Report.html: Pre-hardening scan report, the initial baseline.
• Tailored_Profile_Report.html: Post-hardening report against the tailored profile shipped in this image.
• Raw_STIG_Report.html: Post-hardening report against the unmodified baseline DISA STIG profile.
• Exceptions.txt: Itemized unapplied STIG rules with technical justifications (AWS compatibility, site-specific policies, CSP service conflicts).
• Tuning_Parameters.txt: Every tuning parameter applied on top of the hardening, each shown against its base-image value.
• compliance_mapping.csv: Rule-by-rule mapping to NIST SP 800-53 controls and DISA STIG identifiers with pass/fail statuses.
• package_changes.txt: Package delta against the minimal stock installation.
• sbom.spdx.json: Software Bill of Materials in SPDX format, generated from the RPM database.
• cve_scan.txt / cve_scan_full.txt.gz: Vulnerability scan reports categorizing CVEs by upstream patch availability.
• key_files.sha256: SHA-256 checksums of the key configuration files changed by the hardening, so the delivered state can be verified.
• README.txt: Index of artifact contents, operational guidelines, and configuration defaults.

Reliability Validation:

1. Validation Testing: Functional verification on clean AMI launches through multi-round integration testing, covering the complete messaging lifecycle with SELinux enforcing.

AWS Network & Kernel Tuning:

1. Network Stack: TCP BBR congestion control with fair queueing, increased connection backlogs, buffer adjustments, and MTU probing enabled.

2. System Tuning: Red Hat tuned daemon active with a custom cloud profile, transparent hugepages set to madvise, and modified memory/EBS writeback parameters.

3. EC2 Integration: NVMe I/O timeouts, Amazon Time Sync (chrony), IRQ balance daemon, and size-capped persistent journald logging.

Operational Tools:

1. Preinstalled Tools: AWS SSM Session Manager enabled, CloudWatch Agent installed (disabled by default).

Maintenance:

1. Maintenance Specifications: Rebuilt and updated bi-weekly to monthly incorporating upstream NATS and CentOS Stream 9 security updates, with artifact documentation refreshed per release.

About NATS Server

A lightweight, high-performance open-source messaging system for cloud-native applications, microservices, and IoT device communication, covering publish-subscribe, request-reply, and queue group patterns with sub-millisecond latency and a minimal resource footprint. It complements Apache Kafka and RabbitMQ in multi-broker fabrics, fits IoT pipelines alongside EMQX and Eclipse Mosquitto, and has clients for Python, Node.js, Go, Rust, and Spring Boot.

About CentOS Stream 9

CentOS Stream 9 is a continuously delivered distribution of Red Hat Enterprise Linux, providing a rolling preview of what becomes RHEL. It delivers enterprise-grade stability with a more up-to-date package set than traditional point releases, serves as the upstream source for enterprise derivatives, and stays compatible with AlmaLinux, Rocky Linux, and traditional CentOS deployments.