About KubeFit

KubeFit is an independent trainer for hands-on Kubernetes and Linux exams, built by one person, Bill Gilleran, after those exams bit hard. The motto is "Never skip lab day", the coach is a penguin called Caz, and the rest of these docs stick to commands and failure modes.

Not affiliated with CNCF or The Linux Foundation

KubeFit is not affiliated with, sponsored by, or endorsed by the Cloud Native Computing Foundation (CNCF) or The Linux Foundation. It is not an official training program, and using it is neither required for nor part of any certification.

The official exams, including CKA, CKAD, CKS, LFCS, CNPE, CKNE and ICA, are administered separately by their owners. Register, schedule, and check the current curriculum and exam policies with them: start from CNCF's certification page ↗. Certification names and abbreviations are used here only to say which exam a track helps you prepare for; trademarks belong to their owners.

What it is

The CLI is the gym. kubefit runs timed, graded drills on your machine: kind clusters for the Kubernetes tracks, a disposable Lima VM for LFCS. Tasks, graders and walkthroughs exist only there.
The app is the reading and the record. app.kubefit.com holds each track's Concepts and Playbook, your reports and readiness, notebooks, Coach Caz workouts, the Command recall exercise and your account.
Eight packs of 25 drills, and one 17-question mock exam per track. Seven tracks follow a certification's public domains. The eighth, OPS, is an operations workshop and not a certification.

What it is not

Not an exam simulator with real exam questions. Every scenario is original, written from each exam's public domains. Nothing is recalled or reconstructed from a live exam.
Not a guarantee. Targets are training targets, not official timings; reports and the readiness stage measure your practice evidence, not your chance of passing; 25 drills per pack is not complete coverage of any curriculum.
Not a hosted lab. No drill or exam runs in the browser and there is no cloud cluster: your machine, no meter. The only browser exercise is Command recall, which compares typed text and runs nothing.

Closed-source, free to use

The CLI and the app are closed-source, and free to use. Signup is open: no invite and no waitlist. Every track and feature is available on the free account. The source repository is private; the CLI ships as a signed and notarized macOS binary through a public Homebrew tap and as static Linux builds on the tap's releases page ↗.

Because you cannot read the source, the trust boundary is stated plainly:

Packs are Ed25519-signed, and the CLI refuses any pack that does not verify against its built-in key. See Packs and signing.
Pack scripts act on the clusters and the VM that kubefit creates. LFCS storage and kernel exercises run inside the VM, never on your host.
kubefit end removes what kubefit created. Local files and environment lists everything it writes.

What your account stores

Your email address, and your profile: preferred name, time zone and exam dates.
Your reps: exercise, times, pass or fail, checks passed, attempts, hints and solution use, and whether the rep was paused.
Your mock exam records: track, times, how the exam ended, and each question's check names and results.
Your notes and your saved Coach Caz workout plans.
Your getting-started choices: track, macOS or Linux, and the exam date you gave there.
A hash of each CLI token with its label and when it was last used, and daily counts of API calls for the quotas.

Graders run locally and only results are uploaded. The sync API has no field for manifests, commands or shell history. Command recall progress stays in your browser and is never uploaded.

Contact

hello@kubefit.com for account trouble, mail that never arrived, a grader you think is wrong, or anything else. It reaches the builder directly.