general
Linux technical guides
Practical guides for our Ubuntu, Debian, AlmaLinux and CentOS Stream images: security, web servers, Docker, maintenance.
Access and connection
- Generating an SSH key (Windows, macOS, Linux)How to create an SSH key pair, where the files are, and how to add the public key to BLACKBOX.general
- Transferring files to the server (scp, rsync, SFTP)How to copy files between your computer and your server with scp, rsync or a graphical SFTP client (FileZilla, WinSCP).general
- Server access for colleagues and outside developersHow to give a colleague or a freelancer access to your server without sharing your account, the root password or tokens: SSH keys, separate users, SFTP-only access and revoking access.general
Security
- Securing a new server: checklistThe essential security steps for a new BLACKBOX server, in the right order and without locking yourself out.general
- Firewall: network filtering and ufw/firewalld on the serverHow the two filtering levels work and how to set up ufw or firewalld without locking yourself out.general
- Protection against password-guessing attempts with fail2banInstalling and configuring fail2ban for SSH, checking bans and unblocking an address.general
- System updates and automatic security updatesHow to update the system manually, how to turn on automatic updates and when the server needs a reboot.general
Sites and applications
- Web server with HTTPS: nginx or Apache and Let's EncryptInstalling nginx or Apache, setting up a site for your domain and getting a free Let's Encrypt certificate with certbot.general
- WordPress on LEMP (nginx, MariaDB, PHP)Step-by-step installation of a WordPress site on an Ubuntu or Debian server, with HTTPS, daily backups and basic settings.general
- Databases: MariaDB/MySQL and PostgreSQLInstalling and securing MariaDB and PostgreSQL, remote access through an SSH tunnel, and backups.general
- Installing Docker and Docker ComposeHow to install Docker from the official repository, run applications with Compose, and what you need to know about ports, logs, disk space and memory.general
- Node.js, Python and other services: nginx as a reverse proxyHow to publish an application that listens on an internal port (3000, 8000) on 80/443 with HTTPS, and how to start it automatically with systemd.general
- Moving a site to a BLACKBOX serverA migration plan from another provider: copying the files and the database, testing, and switching DNS without downtime.general
- Sending email from your website and applications (SMTP)How to set up your website, application or server to send email through an authenticated SMTP service, which SPF, DKIM and DMARC records to add, and what to ask support for a mail server of your own.general
Maintenance
- Adding swap spaceHow to create a swap file on a server with little memory, how to tune it, and when an upgrade is the better choice.general
- Backup strategy for your serverWhy backups are your responsibility, what to back up, where to keep the copies, how to automate them with cron, restic or rsync, and how to test a restore.general
- Diagnosing server load (CPU, RAM, disk, network)The basic commands to find out why your server is slow or not responding, and what to do in each case.general