Articles
Explanations, step-by-step guides, cheat sheets and fixes. Pick an area, or tell us what you need.
What kind of help
What do these mean?
- Beginner
- You are new to this topic.
- Intermediate
- You use it, and want to get better.
- Advanced
- You know it well and need the details.
- Guided project
- Build something small from start to finish, step by step.
- Explains an idea
- Plain words on how something works and why.
- Step by step
- Numbered steps to get one task done.
- Cheat sheet
- Commands and options in a table, to look up fast.
- Fixes an error
- An error message, what it means, and how to solve it.
Area
Clear filters
23 entries match these filters
- 0454 Scan your own code and containers in CI: Gitleaks, Semgrep and Trivy Set up a GitHub Actions workflow that runs Gitleaks, Semgrep and Trivy on every push of your own project, learn what each… Intermediate · Step by step · Any system Article Pipelines, runners & hooks · Security testing & CTF 15 Oct 2026
- 0411 CORS explained, and how to fix the browser error The browser blocks a request from one origin to another unless the server allows it with Access-Control headers. Fix it in the… Intermediate · Step by step · Any system, Browser Article Making requests · Web servers & reverse proxies 15 Oct 2026
- 0357 Keep secrets out of git: .env files, gitignore and what to do after a leak Load passwords and API keys from an untracked .env file, commit a safe .env.example instead, catch mistakes before they are pushed, and… Beginner · Step by step · Any system Article Housekeeping · Secrets & access 15 Oct 2026
- 0372 Grafana: your first dashboard from Prometheus data Connect Grafana to a Prometheus server, build a four-panel host dashboard with PromQL queries, set units and thresholds, add an instance variable,… Beginner · Step by step · Browser, Linux, macOS Article Prometheus & Grafana 15 Oct 2026
- 0189 Terraform remote state: backends, locking and migrating local state Move Terraform state from a local file into a shared backend such as S3 with locking, so a team can work safely.… Advanced · Step by step · Any system Article Terraform 15 Oct 2026
- 0152 Build and deploy from source with oc new-app and Source-to-Image How oc new-app turns a Git repository or an image into a running app, how Source-to-Image and Docker builds are chosen, and… Intermediate · Step by step · Any system Article Deploying applications 15 Oct 2026
- 0153 Expose apps with OpenShift Routes: edge, passthrough and re-encrypt TLS A Route publishes a service on a host name through the OpenShift router. Learn when to use plain HTTP, edge, passthrough or… Intermediate · Step by step · Any system Article Deploying applications · Ingress & networking 15 Oct 2026
- 0154 OpenShift app configuration: environment, ConfigMaps, Secrets and persistent storage Set environment variables, load ConfigMaps and Secrets into a Deployment as variables or files, and give it persistent storage with a PersistentVolumeClaim,… Intermediate · Step by step · Any system Article Config, secrets & storage · Deploying applications 15 Oct 2026
- 0137 Helm basics: install a chart, override values, upgrade and roll back Helm installs packaged Kubernetes apps called charts. Learn to add a repository, install a release, customize it with values files, upgrade it… Intermediate · Step by step · Any system Article Helm 15 Oct 2026
- 0150 Logging in with oc and working with OpenShift projects Install the oc client, log in with a password, browser or token, then create, switch and inspect projects. Covers where oc stores… Beginner · Step by step · Any system Article Concepts · Deploying applications 15 Oct 2026
- 0151 Tutorial: deploy a small web app on OpenShift and expose it with a Route A step-by-step first deployment: create a project, build a static website from Git with Source-to-Image, publish it on an HTTPS Route, then… Beginner · Step by step · Any system Article Deploying applications 15 Oct 2026
- 0117 Configure the OCI CLI for Oracle Private Cloud Appliance 3.x Point the standard OCI CLI at a PCA 3.x Compute Enclave: create an API key, write ~/.oci/config with the appliance as the… Intermediate · Step by step · Any system Article Compute, networking & storage 15 Oct 2026
- 0118 Create a compute instance on PCA 3.x with the Compute Web UI or OCI CLI Launch a VM in the Private Cloud Appliance 3.x Compute Enclave: gather an image, shape, subnet and SSH key, then create the… Intermediate · Step by step · Any system Article Compute, networking & storage 15 Oct 2026
- 0119 PCA 3.x networking basics: create a VCN, subnets and security lists On Private Cloud Appliance 3.x, instances need a VCN and a subnet. Create them in the Compute Web UI or OCI CLI… Intermediate · Step by step · Any system Article Compute, networking & storage 15 Oct 2026
- 0120 Block volumes on PCA 3.x: create, attach and mount a data disk Add storage to a Private Cloud Appliance 3.x instance: create a block volume, attach it as paravirtualized, then format and mount it… Intermediate · Step by step · Any system Article Compute, networking & storage 15 Oct 2026
- 0074 pandas basics: read a CSV, filter rows and summarize with groupby Load a CSV into a pandas DataFrame, inspect it, filter rows with conditions, and compute totals per group, with the SQL equivalent… Intermediate · Step by step · Any system Article Data analysis · Files & automation 15 Oct 2026
- 0090 Flexbox and CSS Grid: laying out a page Flexbox arranges items along one line, Grid arranges them in rows and columns at once. Learn the handful of properties that cover… Beginner · Step by step · Browser Article Layout 15 Oct 2026
- 0092 Semantic HTML and accessibility basics, with a responsive page skeleton A minimal responsive HTML page built from semantic elements, plus the accessibility basics every page needs: headings, labels, alt text, keyboard focus,… Beginner · Step by step · Browser Article Accessibility · Layout 15 Oct 2026
- 0038 The pull request workflow on GitHub A pull request asks to merge your branch into another one, with review and automated checks in between. This is the whole… Beginner · Step by step · Any system Article Pull requests 15 Oct 2026
- 0039 A minimal GitHub Actions workflow that runs your tests Add one YAML file under .github/workflows and GitHub runs your tests on every push and pull request. Here is a small, explained… Intermediate · Step by step · Any system Article GitHub Actions 15 Oct 2026
- 0067 Your first SQL queries: SELECT, WHERE, ORDER BY, LIMIT and GROUP BY Read data from a table, keep only the rows you want, sort them, take the first few, and summarize groups with COUNT,… Beginner · Step by step · Any system Article Queries 15 Oct 2026
- 0006 Testing with pytest: first tests, fixtures and parametrize pytest runs plain functions whose names start with test_ and reports every failing assert in detail. This guide covers setup, assertions, exceptions,… Intermediate · Step by step · Any system Article Testing 15 Oct 2026
- 0036 Finding the commit that broke it: log, blame, and git bisect When something used to work and now does not, Git can point at the commit that changed it. Start with log and… Advanced · Step by step · Any system Article Finding bugs · Reading history 15 Oct 2026