4 Systems & infrastructure
Every entry filed under Systems & infrastructure and its subtopics.
43 entries match these filters
- 0055 Docker basics: images, containers and the commands you need An image is a read-only package of an app and its dependencies, and a container is a running instance of it. Learn… Beginner · Concept · Linux, macOS, Windows Article Docker basics 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 · How-to · Linux, macOS, Windows Article Docker basics · Docker Compose 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 · How-to · 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 · How-to · 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 · How-to · 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 · How-to · Any system Article Compute, networking & storage 15 Oct 2026
- 0121 PCA 3.x Service CLI basics: connecting and finding your way around The Service CLI administers the Private Cloud Appliance 3.x Service Enclave. Connect with SSH on port 30006 and use list, show, help,… Intermediate · Reference · Any system Article Administration & monitoring 15 Oct 2026
- 0130 OCI CLI: Oracle Cloud Infrastructure command-line interface Oracle's open-source command-line tool for Oracle Cloud Infrastructure. Private Cloud Appliance 3.x uses the same CLI for its OCI-compatible Compute Enclave. Any system Repo Compute, networking & storage 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 · How-to · Any system Article Helm 15 Oct 2026
- 0139 Collect describe, events and logs of a failing Kubernetes pod A bash script that saves a pod's status, describe output, events, YAML, current and previous logs of every container and its node… Intermediate · How-to · Linux, macOS Script Troubleshooting 15 Oct 2026
- 0140 kubectl cheat sheet: the commands you use every day A compact reference of everyday kubectl commands: contexts and namespaces, listing and inspecting objects, logs and exec, applying changes, rollouts, scaling and… Beginner · Reference · Any system Article Concepts · Troubleshooting 15 Oct 2026
- 0141 List Kubernetes pods that are not Running and Ready A bash script that lists every pod across namespaces that is Pending, failing or running but not ready, with the waiting reason,… Intermediate · Reference · Linux, macOS Script Troubleshooting 15 Oct 2026
- 0147 helm/helm The Helm package manager for Kubernetes: the helm CLI and Go SDK for installing, upgrading and rolling back charts. Any system Repo Helm 15 Oct 2026
- 0148 derailed/k9s K9s is a terminal UI for Kubernetes that lets you browse resources, read logs, open shells and follow cluster changes from the… Any system Repo Troubleshooting 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 · How-to · 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 · How-to · Any system Article Deploying applications 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 · How-to · 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 · How-to · 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 · How-to · Any system Article Config, secrets & storage · Deploying applications 15 Oct 2026
- 0157 oc cheat sheet: everyday OpenShift CLI commands The oc commands you use every day, grouped by task: login and projects, apps and builds, routes, config, debugging, permissions and admin… Intermediate · Reference · Any system Article Deploying applications · Troubleshooting 15 Oct 2026
- 0158 Collect an OpenShift project report with oc A read-only bash script that gathers a project's workloads, pods, routes, builds, storage and warning events, plus describe output and logs of… Intermediate · How-to · Linux, macOS Script Deploying applications · Troubleshooting 15 Oct 2026
- 0159 OpenShift cluster health snapshot: oc adm, nodes, MachineConfigPools and updates An admin overview of OpenShift day-2 checks (cluster version, update channels, cluster Operators, nodes, MachineConfigPools, must-gather) with a read-only bash script that… Advanced · Reference · Linux, macOS Script Cluster administration · Troubleshooting 15 Oct 2026
- 0161 Fix: Error from server (Forbidden): … is forbidden: User … cannot … in OpenShift oc refuses a command with Error from server (Forbidden). The message names the user, verb, resource and project. Learn how to read… Intermediate · Fix · Any system Article Cluster administration · Troubleshooting 15 Oct 2026
- 0163 openshift/oc: the OpenShift command line client Source code of oc, the OpenShift CLI. It is built on top of kubectl, so it can do everything kubectl does, and… Any system Repo Cluster administration · Deploying applications 15 Oct 2026
- 0181 Ansible concepts: inventory, modules, playbooks, idempotency and roles Ansible configures many servers over SSH from one control machine. Learn the core pieces: inventory, modules, tasks, playbooks, roles, and why runs… Beginner · Concept · Linux, macOS Article Ansible 15 Oct 2026
- 0182 Your first Ansible playbook: install nginx and publish a page A complete beginner playbook that installs nginx on Debian or Ubuntu servers, starts it at boot and deploys a home page, with… Beginner · How-to · Linux, macOS Script Ansible 15 Oct 2026
- 0183 Ansible variables, templates and handlers: configure an nginx site Use group variables, Jinja2 templates and handlers together: render an nginx server block from variables, test the config and reload nginx only… Intermediate · How-to · Linux, macOS Script Ansible 15 Oct 2026
- 0184 Ansible Vault: keep passwords and keys encrypted in your repo Ansible Vault encrypts variable files or single values so secrets can live in Git next to your playbooks. Create, edit and rekey… Advanced · How-to · Linux, macOS Article Ansible 15 Oct 2026
- 0185 Ansible ad-hoc commands cheat sheet One-line ansible commands for quick jobs across many servers: ping hosts, run a command, copy files, manage packages, users and services, gather… Intermediate · Reference · Linux, macOS Article Ansible 15 Oct 2026
- 0186 Fix: Ansible UNREACHABLE! Failed to connect to the host via ssh Ansible could not open an SSH session to the host, so no task ran. The text after the colon tells you why:… Intermediate · Fix · Linux, macOS Article Ansible · SSH & servers 15 Oct 2026
- 0187 Terraform concepts: providers, state, plan and apply, modules, and OpenTofu Terraform describes infrastructure in code, compares it with what exists, and changes only the difference. Learn providers, resources, state, the plan/apply loop,… Beginner · Concept · Any system Article Terraform 15 Oct 2026
- 0188 First Terraform configuration: variables, a module and outputs (no cloud needed) A complete Terraform project that writes local files with the hashicorp/local provider, so you can practice init, plan, apply, modules and destroy… Intermediate · How-to · Any system Script Terraform 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 · How-to · Any system Article Terraform 15 Oct 2026
- 0190 Fix: Terraform Error acquiring the state lock Another run holds the lock on your Terraform state, or a crashed run left it behind. Find out who holds it, wait… Advanced · Fix · Any system Article Terraform 15 Oct 2026
- 0194 Ansible: agentless IT automation The source repository of ansible-core, the engine behind Ansible playbooks, ad-hoc commands and the ansible-galaxy and ansible-vault tools. Linux, macOS Repo Ansible 15 Oct 2026
- 0195 OpenTofu: open-source infrastructure as code OpenTofu is the community fork of Terraform under the MPL-2.0 license, run as a Linux Foundation project. It uses the same configuration… Any system Repo Terraform 15 Oct 2026
- 0250 Containerize a Node.js app and run it with PostgreSQL using Docker Compose Package a small Node.js web app in a multi-stage Docker image, then run it next to PostgreSQL with Docker Compose, named volumes,… Intermediate · Tutorial · Linux, macOS, Windows Article Docker basics · Docker Compose · PostgreSQL 15 Oct 2026
- 0251 Learn Kubernetes on your laptop with kind: from first cluster to Ingress Build a throwaway Kubernetes cluster in Docker with kind, deploy a web app with config, secrets and probes, scale it, roll out… Beginner · Tutorial · Linux, macOS, Windows Article Concepts · Workloads & services 15 Oct 2026
- 0252 Package a web app as a Helm chart: create, test, install, upgrade and roll back Turn a small nginx web app into your own Helm chart, check it with lint and template, install it into a namespace,… Intermediate · Tutorial · Any system Article Helm 15 Oct 2026
- 0253 Take an app to production on OpenShift: S2I build, TLS Route, storage, autoscaling and network policy Build a small Python app from Git with Source-to-Image on OpenShift or OKD, then add an HTTPS Route, config and secrets, storage,… Intermediate · Tutorial · Linux, macOS, Windows Article Concepts · Deploying applications 15 Oct 2026
- 0254 Automate three servers with Ansible: roles, templates, Vault and safe dry runs Build a real Ansible project for two web servers and one database server: inventory groups, SSH keys, roles, templates, handlers, an encrypted… Intermediate · Tutorial · Linux, macOS Article Ansible · Keys & config 15 Oct 2026
- 0256 Manage infrastructure as code with Terraform: from first file to plans on pull requests Learn the full Terraform workflow without a cloud account: variables, a module, outputs, state, plan, apply and destroy, a backend for shared… Beginner · Tutorial · Linux, macOS, Windows Article GitHub Actions · Terraform 15 Oct 2026
- 0265 Turn a one-liner into a robust bash script: strict mode, options, logging, traps, locking and a schedule Grow a find-and-gzip one-liner step by step into a dependable bash script with strict mode, getopts, usage text, logging, error traps, dry-run,… Intermediate · Tutorial · Linux, macOS Article Services & systemd · Shell scripting 15 Oct 2026