Pillar Hub / Master Index

The Ultimate Linux & Cloud Security Architecture Cheatsheet (2026)

[ ARCHITECTURE ] Zero Dependencies
[ NOTE ] 25 Architecture Blueprints

Architectural Philosophy

This master index contains 25 highly technical, production-ready blueprints for Linux and Cloud-Native security. From kernel-level eBPF routing to unprivileged Landlock sandboxing and zero-trust HashiCorp Vault SSH CA authentication. Bookmark this page as your ultimate zero-dependency reference hub.

1. Kernel & eBPF Security (The Next-Gen)

ARCHITECTURE BLUEPRINT

Understanding Linux eBPF Security Monitoring

The theoretical and practical foundation for transitioning from legacy kernel modules to eBPF for O(1) complexity observability and network routing.

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ARCHITECTURE BLUEPRINT

eBPF XDP Packet Filtering & DDoS Mitigation

Drop malicious packets directly at the Network Interface Card (NIC) driver level before they even reach the Linux network stack (skb).

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ARCHITECTURE BLUEPRINT

Cilium eBPF Host Routing & Tetragon Tracing

Completely bypass kube-proxy and iptables overhead using Cilium's eBPF host routing, coupled with Tetragon's in-kernel process enforcement.

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ARCHITECTURE BLUEPRINT

Rust in the Linux Kernel: Memory Safety Blueprint

How the integration of Rust (`rust/kernel/`) eliminates use-after-free and buffer overflow vulnerabilities at compile-time within driver subsystems.

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2. System Isolation & Sandboxing

ARCHITECTURE BLUEPRINT

Linux Landlock LSM Unprivileged Sandboxing

Implement filesystem access control policies without requiring root privileges (`CAP_SYS_ADMIN`), replacing legacy AppArmor/SELinux overhead.

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ARCHITECTURE BLUEPRINT

Linux Seccomp-BPF Syscall Filtering

Dramatically reduce the attack surface of containerized workloads by filtering unneeded syscalls (e.g., `ptrace`, `unshare`) via BPF.

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ARCHITECTURE BLUEPRINT

Systemd Service Sandboxing & Hardening

Lock down system daemons using Native systemd directives like `ProtectSystem=strict`, `PrivateTmp=yes`, and `ProtectHome=yes`.

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ARCHITECTURE BLUEPRINT

Chroot Jails & Unprivileged Namespaces Isolation

The underlying primitives of Docker/Podman: utilizing user namespaces (`CLONE_NEWUSER`) and mount namespaces to isolate untrusted binaries.

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ARCHITECTURE BLUEPRINT

Wasm (WebAssembly) WASI Runtime Sandboxing

Execute backend microservices inside Wasm linear memory sandboxes with explicit WASI capability grants for ultimate zero-trust execution.

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3. Access Control & Zero-Trust Auth

ARCHITECTURE BLUEPRINT

Linux VPS Hardening Guide (2026)

The definitive day-zero baseline checklist: disabling root login, configuring chrony, unattended-upgrades, and locking down SSH.

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ARCHITECTURE BLUEPRINT

Vault SSH CA Short-Lived Certificates

Eliminate static `authorized_keys` management. Use HashiCorp Vault to sign ephemeral SSH certificates that expire automatically after 8 hours.

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ARCHITECTURE BLUEPRINT

Zero-Trust SSH Access with FIDO2

Require hardware-backed YubiKey authentication (`[email protected]`) for cryptographic proof of physical presence.

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ARCHITECTURE BLUEPRINT

PAM Faillock Account Lockout Policies

Configure Pluggable Authentication Modules (PAM) to automatically lock user accounts after consecutive failed authentication attempts.

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ARCHITECTURE BLUEPRINT

Fail2Ban Intrusion Prevention Mitigations

Automated log parsing and iptables blocking for brute-force SSH and web application attacks.

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4. Network & Web Architecture

ARCHITECTURE BLUEPRINT

Linux Kernel Sysctl Network Stack Hardening

Mitigate SYN floods, ICMP smurf attacks, and IP spoofing by tweaking `/etc/sysctl.conf` networking parameters.

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ARCHITECTURE BLUEPRINT

UFW Firewall Hardening & Rate Limiting

Establish strict default-deny ingress policies and implement application-level rate limiting (`ufw limit ssh/tcp`).

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ARCHITECTURE BLUEPRINT

WireGuard VPN Tunneling for VPS Mesh Networks

Replace OpenVPN with WireGuard's stateless, cryptographically opinionated (ChaCha20-Poly1305) kernel-space VPN tunnels.

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ARCHITECTURE BLUEPRINT

NGINX Reverse Proxy Security Hardening

Stripping server headers, implementing TLS 1.3 exclusively, and optimizing proxy buffer sizes against Slowloris attacks.

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ARCHITECTURE BLUEPRINT

HTTP/3 QUIC 0-RTT Replay Mitigations

Understand the architectural risks of QUIC's 0-RTT early data and how to disable it on state-modifying API routes.

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ARCHITECTURE BLUEPRINT

Strict Content Security Policy (CSP) Engineering

Eradicate XSS entirely by enforcing strict nonce-based CSP headers and disabling inline execution.

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5. Cloud-Native & DFIR Pipeline

ARCHITECTURE BLUEPRINT

Kubernetes Pod Security Standards (PSS)

Enforce `Restricted` profiles via Admission Controllers to prevent container escapes and root privilege escalations inside clusters.

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ARCHITECTURE BLUEPRINT

Sigstore Cosign Keyless Image Signing (SLSA)

Implement supply chain security by cryptographically signing OCI container images using GitHub Actions OIDC identity.

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ARCHITECTURE BLUEPRINT

Auditd Kernel Event Monitoring & DFIR

Configure the Linux Audit daemon to track specific `execve` syscalls and file modifications for forensic investigations.

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ARCHITECTURE BLUEPRINT

DFIR Pipelines with Vector & ClickHouse

Stream raw audit logs efficiently using Vector (Rust) into a columnar ClickHouse database for ultra-fast SIEM queries.

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ARCHITECTURE BLUEPRINT

Minimalist Architecture (Pure CSS & Static Hosting)

Why reducing architectural complexity (removing Node/Python backends) is the ultimate security and performance posture.

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