eBPF & Cilium Learning Roadmap

Goal: From zero eBPF exposure to production-grade Cilium networking, observability, and security

Learning Phases

Phase 1: eBPF Fundamentals (2-3 days)

•What eBPF is and why it's kernel-safe (the verifier, at a conceptual level)

•Why DevOps cares — zero-instrumentation observability

•eBPF vs. sidecar proxies — the performance argument

•The tool landscape: Cilium, Tetragon, Hubble, Falco, bpftrace, Pixie

Phase 2: Cilium Networking (3-4 days)

•Cilium as CNI — replacing kube-proxy

•CiliumNetworkPolicy — L3/L4 and L7/HTTP-aware policies

•Hubble flow observability — CLI and UI

Phase 3: Runtime Security and Investigation (3-4 days)

•Tetragon — active enforcement vs. Falco's detection-only model

•bpftrace — ad hoc kernel tracing for live investigation

•XDP — line-rate packet filtering

•Pixie — auto-instrumented application observability

Phase 4: Advanced Kernel and Networking Internals (1-2 weeks)

•Verifier internals — what actually gets rejected and why

•CO-RE (Compile Once – Run Everywhere) and BTF

•Transparent encryption — WireGuard vs. IPSec tradeoffs

•Egress Gateway for consistent outbound IPs

Phase 5: Troubleshooting and Interview Readiness (ongoing)

•Diagnosing policy-drop mysteries with hubble observe --verdict DROPPED

•Cross-cluster connectivity debugging

•Practice explaining the eBPF-vs-sidecar performance argument concretely — a near-certain interview topic given how frequently eBPF comes up as a "modern infrastructure" signal

Job Roles This Enables

•Platform Engineer (networking-focused)

•Site Reliability Engineer

•Security Engineer (runtime security, via Tetragon/Falco)

•Kubernetes/Cloud-Native Infrastructure Engineer

Target Certifications

(needs verification — recheck against current source for CNCF's current Cilium-relevant certification offerings, if any)

How to Use This Roadmap

1.Work through phases in order — Phase 3's Tetragon/bpftrace/XDP material assumes Phase 2's Cilium/Hubble fundamentals are already solid, and Phase 4's verifier/CO-RE internals are meaningfully easier once Phase 1-3's practical tool usage is familiar

2.This technology doesn't have a separate Labs tab — the Fundamentals/Intermediate/Advanced code blocks and a real cluster (kind works, per the Installation section's local setup) are the hands-on material

3.Build the portfolio projects in projects.md after Phase 3 — demonstrating both networking policy and runtime security enforcement shows the breadth eBPF tooling actually covers

4.Use cilium connectivity test liberally during learning, not just after installation — it's a genuinely useful tool for confirming a policy change did what you intended

5.Treat Phase 4 as valuable even if you'll never write raw eBPF programs yourself — understanding the verifier and CO-RE is what separates "I've used Cilium" from genuinely understanding why the tooling works the way it does, which interviewers specifically probe for at senior levels

Prerequisites

See prerequisites.md in this section for what you should know before starting.

Revision Notes

Total time: 3-5 weeks (part-time)
eBPF/Cilium has a real conceptual depth beyond most CNI/networking
tools — budget extra time for Phase 4 specifically if the goal is
interview-level depth, not just operational competence with Cilium's
day-to-day CLI/Helm interface

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