When you first use git on a machine, you’ll need to configure your identity. Git uses these credentials to author your commits: git config –global user.name “Your Name” git config –global user.email you@example.com These settings are stored in ~/.gitconfig and apply to all repositories on your system. Verifying your configuration Check what you’ve set: git…
Open a terminal and connect to the server: ssh USER@HOST Replace USER with your username and HOST with the server’s hostname or IP address. On first connection, SSH will display the host key fingerprint: The authenticity of host ‘HOST (IP_ADDRESS)’ can’t be established. ECDSA key fingerprint is SHA256:xxxxxxxxxxxx. Are you sure you want to continue…
Running commands across multiple servers is fundamental to cluster management and infrastructure automation. While orchestration tools like Ansible and Terraform dominate modern deployments, sometimes you need lightweight solutions that work without dependencies—or you’re already invested in SSH-based infrastructure. When managing clusters, you typically work in two modes: serial execution (one node at a time) and…
Blocking JavaScript per-site in Chrome lets you stop intrusive scripts, malicious content, or resource-heavy trackers without disabling JavaScript globally. This gives you surgical control—some sites work fine without JS, while others need it. Access the JavaScript exceptions page Open Chrome and navigate to this URL in the address bar: chrome://settings/contentExceptions#javascript Alternatively, go through the menu:…
When SSH fails but the daemon still runs, or when kernel panics strike, you need automated recovery without physical access. This guide covers three essential techniques: forcing reboots when the system is unresponsive, auto-recovery from kernel panics, and alerting you when it happens. Force a reboot when SSH is unresponsive If a server stops responding…
Chrome on Linux uses NSS (Network Security Services) for certificate management. Install the certutil utility from your distribution: Debian/Ubuntu/Linux Mint: sudo apt install libnss3-tools CentOS/Fedora/RHEL: sudo dnf install nss-tools Arch Linux: sudo pacman -S nss Extract and Import the Certificate The most reliable approach is to extract the certificate directly from the server and import…
Hadoop 2.x reached end-of-life in 2016. This guide covers setup for learning purposes and legacy system maintenance only. For production deployments, use Hadoop 3.x or later, which includes performance improvements, better YARN scheduling, HDFS erasure coding, and improved security. Cloud-managed options like AWS EMR, Google Dataproc, and Azure HDInsight eliminate most operational overhead. This guide…
You often need to access a Git server that only accepts internal connections, but you have SSH access to an intermediate host that can reach it. This is common in corporate environments where the Git server sits behind a firewall. You can tunnel Git traffic through the intermediate host without manually managing tunnels for each…
Fedora has evolved its hostname management over the years. Modern versions use systemd and the /etc/hostname file, while older releases relied on /etc/sysconfig/network. Here’s how to handle both scenarios. Using hostnamectl (Recommended) The most straightforward method on current Fedora is using hostnamectl, which handles hostname changes through systemd: sudo hostnamectl set-hostname newname.example.com For a hostname…
Linux provides multiple ways to query network configuration. While the underlying concepts remain consistent, modern tools have evolved from the older net-tools utilities. IP Address, MAC Address, and Netmask The modern replacement for ifconfig is ip addr: $ ip addr show This displays all network interfaces with their IPv4 and IPv6 addresses, MAC addresses, and…
Hadoop 3.x remains the current stable version with YARN improvements, HDFS federation, and erasure coding. Hadoop 1.x and 2.x are no longer maintained. For new deployments, evaluate whether Hadoop fits your needs or if managed services like AWS EMR, Google Dataproc, or Azure HDInsight better suit your infrastructure. This post covers common configuration mistakes and…