Reference sheets for shipping under pressure
Command-first references for Kubernetes, security, APIs, Linux, DevSecOps, Docker, Git, SQL, and Python. Each sheet is written for real production work: what to run, when to use it, and what can go wrong.
References for production infrastructure
Use these sheets when the decision has operational risk: identity, authorization, runtime defense, network paths, API authentication, and artifact trust.
Security
Kubernetes Security
RBAC audit, PodSecurity standards, NetworkPolicy default-deny, secrets, image signing, runtime forensics, and security warnings for cluster changes.
Cloud native
Kubernetes kubectl
Core kubectl commands for pods, deployments, services, debugging, logs, configs, and secrets.
Cloud native
SPIFFE & SPIRE
SPIFFE IDs, SVID issuance, SPIRE CLI commands, registration entries, federation, and workload attestation patterns.
Reference
OPA & Rego
Rego syntax, OPA policy patterns, Kubernetes admission examples, Gatekeeper constraints, and policy testing flows.
Security
API Security
JWT validation, OAuth2 flows, secure headers, mTLS, webhook signing, and OWASP API defenses.
Reference
Linux Networking
iptables, nftables, tcpdump, OpenSSL, certificate debugging, eBPF tracing, and routing inspection.
Security
Runtime Security
Falco rules, eBPF observability, Tetragon, syscall context, and production alert tuning patterns.
Cloud native
Service Mesh
Istio traffic management, Envoy diagnostics, mTLS configuration, and AuthorizationPolicy examples.
Reference
DevSecOps & Supply Chain
cosign, SBOMs, SLSA provenance, GitHub Actions hardening, and CI/CD gates for artifact trust.
Engineering essentials
Compact references for the commands engineers reach for repeatedly: containers, source control, query debugging, and Python runtime work.
Docker
Build, run, compose, volumes, networks, multi-stage builds, and container debugging commands.
Git
Branch, merge, rebase, stash, reset, log, diff, cherry-pick, and recovery workflows.
SQL
SELECT, JOIN, GROUP BY, window functions, CTEs, indexes, and query performance patterns.
Python
Core syntax, list comprehensions, f-strings, decorators, OOP, file I/O, errors, and virtual environments.
Command lists are not enough
These sheets include production notes, security warnings, and hardened alternatives so the command is tied to a decision. Pair them with courses for depth and labs for practice.