Strace is a debugging tool that will help you troubleshoot issues. Strace monitors the system calls and signals of a specific program. It is helpful when you do not have the source code and would like to debug the execution of a program. strace provides you the execution sequence of a binary from start to end. This article explains 7 strace examples to get you started. 1. Trace the Execution of an Executable You can ... Read more
Introduction Virtual Hosts Virtual Hosts are a way to host more than one domain from a single IP address/server. This could be helpful, for example, to people who wish to host more than one website from a single droplet. The visitors of the websites will be shown the correct information based on the domain they are accessing, whereas, without virtual hosts correctly setup, all domains would display the same information. There is no limit to ... Read more
Introduction ProcessWire is a flexible, open-source PHP Content Management System. It is easy to update for clients and a pleasure to work with for developers. System requirements You will need a standard LAMP stack to run ProcessWire. When creating your droplet, under Applications, choose LAMP on Ubuntu . A full list of requirements is available here . Update Ubuntu To ensure that all of your modules install correctly, be sure to run the following command ... Read more
Introduction TLS , or transport layer security, and its predecessor SSL , which stands for secure sockets layer, are web protocols used to wrap normal traffic in a protected, encrypted wrapper. Using this technology, servers can send traffic safely between the server and the client without the concern that the messages will be intercepted and read by an outside party. The certificate system also assists users in verifying the identity of the sites that they ... Read more
Introduction Piwigo is a free, open-source, and customizable photo gallery software program distributed under the GNU General Public License (version 2). In this guide, we will focus on getting Piwigo installed with the Apache web server on Ubuntu 14.04. At the end of this tutorial, you'll have a working photo gallery with multiple albums. You can add pictures from a browser-based control panel, and let anyone view your gallery from the web. Prerequisites Before you ... Read more
Introduction How do you keep track of authorized and unauthorized activity on your server? OSSEC is one tool you can install on your server to keep track of its activity. OSSEC is an open-source, host-based intrusion detection system (HIDS) that performs log analysis, integrity checking, Windows registry monitoring, rootkit detection, time-based alerting, and active response. It can be used to monitor one server or thousands of servers in a server/agent mode. If properly configured, OSSEC ... Read more
Introduction Ansible is a configuration management tool that system administrators use to automate infrastructure management activities. Ansible uses only SSH to run commands remotely, and thus does not need an agent on the remote server. This makes Ansible preferable over other popular tools like Puppet or Chef when you don't want to install agents on the managed servers. Moreover, it is much easier to get started with Ansible because it uses YAML (Yet Another Markup ... Read more
Introduction Calibre is a free and open source ebook manager. Although Calibre is probably better known for its desktop client, it can also act as a powerful server, allowing you to access your ebooks from anywhere in the world (or share your collection with friends). Keeping your ebooks on a server is great, as you aren't reliant on having the same reading device with you whenever you want to read. And if you go traveling, ... Read more
Introduction Redis is an open-source key value store that can operate as both an in-memory store and as cache. Redis is a data structure server that can be used as a database server on its own, or paired with a relational database like MySQL to speed things up, as we're doing in this tutorial. For this tutorial, Redis will be configured as a cache for WordPress to alleviate the redundant and time-consuming database queries used ... Read more
Introduction SchoolTool is an open-source student management system alternative to Blackboard or Pearson’s PowerSchool. It can be used to manage any of the following records a school might keep: Achievement and goal tracking Attendance journals Event calendars Gradebooks Guardian/parent, staff, and student contact information Infraction/intervention reports School administrators, clerks, students, and teachers can access SchoolTool using a typical web browser. Unlike PowerSchool, it does not require the Java Runtime Environment. Prerequisites Make sure you have ... Read more