DevOps Nimbus GitHub

DevOps Nimbus

Zero to on-call.

Ten free tracks that take you from your first Linux command to the engineer people page at 3 a.m. Learn each tool step by step, then prove it on real incidents, with real error messages, in your browser.

Learn DevOps Fix an error now ›
  1. Linux
  2. Bash
  3. Python
  4. Docker
  5. Kubernetes
  6. Ansible
  7. Terraform
  8. AWS
  9. Actions
  10. DevSecOps
10
tracks, basics to production
555
incidents to fix in simulators
704
errors explained, with fixes
$0
no accounts, no ads, no tracking

Pick a track

Each one stands alone. Following them in order builds from a single server to a secure, automated cloud delivery.

  1. Linux

    Ubuntu and Rocky Linux servers that misbehave: full disks, failing services, SELinux, firewalls, boot problems.

    60 incidents · 89 errors explained

    Open Linux

  2. Bash and shell

    Bash scripts that do not surprise you at 3 a.m.: quoting, exit codes, pipes, traps, cron and background jobs.

    66 incidents · 78 errors explained

    Open Bash and shell

  3. Python for DevOps

    Automation scripts that do not hang, leak secrets or fail silently: HTTP, subprocess, files, logging, packaging.

    53 incidents · 76 errors explained

    Open Python for DevOps

  4. Docker

    Build it small, run it safe: images and layers, networks, volumes, registries, limits and container security.

    46 incidents · 66 errors explained

    Open Docker

  5. Kubernetes

    Fix a broken practice cluster: Pods that will not start, Services, Ingress, storage, scheduling, RBAC and upgrades.

    73 incidents · 66 errors explained

    Open Kubernetes

  6. Ansible

    Configure a hundred servers like one: inventories, variables, roles, handlers, idempotency, vault and rolling updates.

    43 incidents · 68 errors explained

    Open Ansible

  7. Terraform

    Read the plan before it reads you: state, drift, replacements, modules, providers, locking and CI.

    49 incidents · 75 errors explained

    Open Terraform

  8. AWS

    The cloud without the surprise bill: IAM, VPC networking, compute, storage, databases, containers and cost traps.

    60 incidents · 71 errors explained

    Open AWS

  9. GitHub Actions

    Pipelines you can trust: triggers, matrices, caching, secrets, environments, OIDC and workflow security.

    56 incidents · 57 errors explained

    Open GitHub Actions

  10. DevSecOps

    Catch it before production: leaked secrets, vulnerable dependencies, image and IaC scanning, signing and SBOMs.

    49 incidents · 58 errors explained

    Open DevSecOps

Find a fix for an error

Every track has a troubleshooting reference: the exact error, what it means, how to confirm the cause, the fix, how to prevent it, and an incident to practise it on. Paste your error into the track's search, or browse the full list.

How every track works

  • Path

    Levels from absolute basics to production, each with what you learn and a hands-on lab.

  • Playground

    A simulator of the real tool. Each incident has a story, three hints and a lesson, and tempting wrong fixes do not count.

  • X-ray

    Paste a config file or script to get every line explained and the risky ones flagged.

  • Quiz

    Scenario questions for each level, with the reasoning behind every answer.

  • Cheat sheet

    The commands people actually use, each marked Try (runs in the playground) or Lab.

  • Scoreboard

    A score and rank, a skill radar of every stage, and your learning uptime against an SLO, with on-call shifts against the clock.

  • How it works

    An interactive diagram of how the tool works inside, part by part: its architecture, or the steps a command, play or run goes through.

Everything runs in your browser. There are no accounts, cookies or trackers, and nothing is sent anywhere. Each track keeps your progress only in this browser and has a button to clear it.