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50 entries match these filters

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 · How-to · 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 · How-to · Any system Article Finding bugs · Reading history 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 · How-to · 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 · How-to · 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 · How-to · Linux, macOS Article Finding files & text · Text processing 15 Oct 2026
0053 Set up SSH keys: ssh-keygen, ssh-copy-id and ~/.ssh/config SSH keys let you log in to servers and push to Git hosts without typing a password. Create an ed25519 key, install… Beginner · How-to · Linux, macOS, Windows Article Keys & config 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
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 · How-to · Any system Article Queries 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 · How-to · 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 · How-to · 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 · How-to · Browser Article Accessibility · Layout 15 Oct 2026
0099 Proxmox VE repositories and updates: enterprise vs no-subscription A fresh Proxmox VE install uses the enterprise repository, which needs a subscription. Learn how to switch to the no-subscription repository and… Beginner · How-to · Linux Article Installation & first steps · Packages & updates 15 Oct 2026
0100 Create a VM and a cloud-init template with qm Create KVM virtual machines from the command line with qm, then build a reusable cloud-init template from a cloud image and clone… Intermediate · How-to · Linux Article Basics · VMs & containers 15 Oct 2026
0101 Create LXC containers with pct and pveam Download a container template with pveam, create an unprivileged LXC container with pct, give it a network address and get a shell… Beginner · How-to · Linux Article VMs & containers 15 Oct 2026
0103 Proxmox VE networking: Linux bridges (vmbr0) and VLANs Guests reach the network through Linux bridges such as vmbr0, defined in /etc/network/interfaces. Learn the default setup, VLAN-aware bridges, VLAN tags for… Intermediate · How-to · Linux Article Installation & first steps · Networking & firewalls 15 Oct 2026
0104 Build a Proxmox VE cluster with pvecm and live-migrate VMs Join Proxmox VE nodes into a cluster with pvecm create and pvecm add, check quorum with pvecm status, then move running VMs… Advanced · How-to · Linux Article Clusters & high availability · VMs & containers 15 Oct 2026
0106 Back up and restore guests with vzdump, backup jobs and Proxmox Backup Server Back up Proxmox VE VMs and containers with vzdump, choose a backup mode, schedule backup jobs with retention, restore with qmrestore or… Intermediate · How-to · Linux Article Backup & restore 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
0125 Create a KVM virtual machine with virt-install Use virt-install to create libvirt/KVM guests: install from an ISO, run a text-only install over the serial console, or import a cloud… Intermediate · How-to · Linux Article Basics 15 Oct 2026
0126 KVM snapshots and cloning with virsh and virt-clone Take, list, revert and delete libvirt snapshots with virsh, understand internal vs external and disk-only snapshots, and clone a stopped VM with… Advanced · How-to · Linux Article Basics 15 Oct 2026
0135 Deploy your first app on Kubernetes A step-by-step tutorial: write a Deployment and a Service in YAML, apply them, reach the app, add health probes, roll out a… Beginner · How-to · Linux Article Ingress & networking · Workloads & services 15 Oct 2026
0136 Persistent storage in Kubernetes: PersistentVolumes, claims and StorageClasses How to give a Pod storage that survives restarts: request it with a PersistentVolumeClaim, let a StorageClass provision it, and mount it.… Intermediate · How-to · Linux Article Config, secrets & storage · Workloads & services 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
0138 Kubernetes RBAC basics: least-privilege access for a service account RBAC controls who may do what in a cluster with Roles, ClusterRoles and bindings. This guide grants a CI service account deploy… Advanced · How-to · Linux Article Concepts · Config, secrets & storage 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
0165 Write a systemd service unit for your own app Turn any long-running program into a proper service: create a unit file, run it as an unprivileged user, restart it on failure… Intermediate · How-to · Linux Article Services & systemd 15 Oct 2026
0166 Replace a cron job with a systemd timer A systemd timer runs a service on a schedule like cron, but logs every run to the journal, can catch up missed… Intermediate · How-to · Linux Article Services & systemd 15 Oct 2026
0169 Add a new disk: partition, format and mount it by UUID Find a new disk with lsblk, partition it with parted, create an ext4 or XFS filesystem and mount it permanently through /etc/fstab… Intermediate · How-to · Linux Article Disks, LVM & filesystems 15 Oct 2026
0173 Set a static IP address: nmcli on RHEL vs netplan on Ubuntu RHEL, Rocky and AlmaLinux configure networking with NetworkManager (nmcli); Ubuntu Server uses netplan YAML. Here is the same static IP setup in… Intermediate · How-to · Linux Article Networking & firewalls 15 Oct 2026
0175 Open ports with firewalld and ufw firewalld (RHEL, Rocky, AlmaLinux) and ufw (Ubuntu) are friendly front ends to the kernel firewall. Allow SSH first, then open only the… Intermediate · How-to · Linux Article Networking & firewalls 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
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
0192 Grafana basics: connect Prometheus, build a dashboard and set up an alert Connect Grafana to Prometheus, build a dashboard for your servers with PromQL panels and a host selector, and create an alert rule… Intermediate · How-to · Linux Article Prometheus & Grafana 15 Oct 2026
0198 Install PostgreSQL and connect with psql on Debian, Ubuntu and RHEL Install the PostgreSQL server from your distribution or the official PGDG repositories, start it, and open your first psql session as the… Beginner · How-to · Linux Article Install & connect 15 Oct 2026
0200 PostgreSQL roles, privileges and default privileges Create login and group roles, grant access to databases, schemas and tables, and use ALTER DEFAULT PRIVILEGES so tables created later get… Intermediate · How-to · Linux Article Roles & administration · Security & access 15 Oct 2026
0202 Back up and restore PostgreSQL with pg_dump, pg_restore and pg_dumpall Make logical backups of one database with pg_dump, of roles and the whole cluster with pg_dumpall, and restore them with pg_restore or… Beginner · How-to · Linux Article Backup & restore 15 Oct 2026
0205 Set up PostgreSQL streaming replication with a hot standby Step-by-step: prepare a primary, clone it with pg_basebackup, start a read-only standby that streams WAL, check it works, and understand promotion and… Advanced · How-to · Linux Article Replication & high availability 15 Oct 2026
0214 MySQL users and privileges: CREATE USER, GRANT and authentication plugins A MySQL account is a user name plus the host it connects from. You create it with CREATE USER, give it rights… Beginner · How-to · Linux Article Administration · Security & access 15 Oct 2026
0218 Setting up MySQL source-replica replication with GTIDs Step by step: configure a MySQL 8.4 source and replica with GTIDs, create the replication account, copy the data, connect the replica… Advanced · How-to · Linux Article Administration · Replication 15 Oct 2026
0225 Oracle Data Pump: export and import schemas with expdp and impdp Data Pump moves schemas, tables or whole databases between Oracle databases as dump files. Set up a directory object, export with expdp… Intermediate · How-to · Linux, Windows Article Administration · Backup with RMAN 15 Oct 2026
0233 Turn on MongoDB authentication and create least-privilege users A fresh MongoDB install accepts connections without a password. Create a user administrator, enable authorization, then give each application and backup job… Intermediate · How-to · Linux Article Administration · Security & access 15 Oct 2026
0242 Database security checklist: access, encryption, exposure and patching A practical checklist for hardening any database server, with MongoDB and Redis examples: no public exposure, authentication, least privilege, TLS, protected backups,… Advanced · How-to · Linux Article Database operations · Security & access 15 Oct 2026
0243 Database backup strategy: the 3-2-1 rule and testing restores Keep three copies of your data on two kinds of storage with one copy offsite, choose dump or snapshot methods per database,… Intermediate · How-to · Linux Article Database operations · Security & access 15 Oct 2026