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- 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
- 0432 Try Sigma rules against your own logs Install the sigma-cli converter, take a rule from the public SigmaHQ library, convert it into a query for a log tool you… Intermediate · Step by step · Linux, macOS Article Logs · Security resources & detection 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
- 0422 Dotfiles: keep your shell setup in git Put .bashrc, .zshrc, .gitconfig and your editor settings into a git repository so a new machine is set up in minutes: a… Intermediate · Step by step · Linux, macOS Article Modern command-line tools · Setup 15 Oct 2026
- 0363 Restore drill: prove your backup works in 15 minutes A repeatable procedure to restore one file and one database from your newest backup into a scratch location, compare the result with… Intermediate · Step by step · Linux, macOS Article Backup tools · Strategy & restore drills 15 Oct 2026
- 0330 Write a Dockerfile: FROM, COPY, RUN, CMD and multi-stage builds How a Dockerfile turns into an image layer by layer, what the main instructions do, how to order them for fast rebuilds,… Intermediate · Step by step · Linux, macOS, Windows Article Docker basics · Images & registries 15 Oct 2026
- 0331 docker compose for an app with a PostgreSQL database A compose.yaml that runs your application next to a PostgreSQL container, with a named volume for the data, a health check so… Intermediate · Step by step · Linux, macOS, Windows Article Docker Compose · Install & connect 15 Oct 2026
- 0332 Tag, push and pull images with Docker Hub and other registries How image names map to registries, how to log in, tag and push an image to Docker Hub, GitHub Container Registry or… Intermediate · Step by step · Linux, macOS, Windows Article Images & registries 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
- 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
- 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
- 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
- 0052 Slice and summarize text with grep, sort, uniq, cut, awk and sed A handful of classic tools can filter, count, extract and rewrite text right in the terminal. This guide shows the patterns you… Intermediate · Step by step · Linux, macOS Article Finding files & text · Text processing 15 Oct 2026
- 0056 Docker Compose: run a small web app with a database Docker Compose describes several containers, their ports, volumes and environment in one compose.yaml file, then starts them all with docker compose up. Intermediate · Step by step · Linux, macOS, Windows Article Docker basics · Docker Compose 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