APT, one of the technologies that made Debian (and its derivatives, such as Ubuntu) highly popular, became mainstream for production deployments during the same time span that web applications broke through the barriers of enterprise fitness, reliability, and scalability.
The flexibility of Debian systems makes it very appealing for web DevOps and modern web apps. This book tries to simplify deployment and reduce time-to-market, while providing a solid foundation for you to grow your Debian sysadmin practices.
In the first part of the book we’ll help you choose the right flavor of Debian, install it, and prepare for multiple and massive installations, should you need it. We will also guide you through the initial APT setup, installing the stack, and configuring storage and frameworks.
In the second part of the book, we harden the installation, analyze scalability paths, and learn how to effectively maintain your system, including backup/restore and performance. We also provide a future look at cloud and incident response, which will help you get the most out of your installation in the long run.
Choosing the right flavor of Debian (Simple) explains how Debian organizes software, the architectures, and installation methods, and indicates a set of criteria for system administrators to choose and get the right media.
Installing Debian GNU/Linux (Simple) goes through the installation process, including partitioning, networking, and using tasksel to install an initial set of packages to work with.
Making Debian GNU/Linux installations scalable (Medium) discusses methods to automate and scale Debian installations, such as debconf preseeding.
Preparing the APT packaging system for your environment (Simple) explains how to configure APT and use APT tools, such as apt-get for package management.
Installing your application platform stack (Simple) goes through the installation of an Apache or Nginx stack, as well as PHP and other components, and the databases—all in the Debian way.
Setting up your storage, security, and permissions (Simple) goes through the mount-level and user-level options to implement a security strategy for your application storage.
Setting up your database/data storage (Medium) explores how to configure the databases and their underlying storage.
Configuring your programming language libraries (Medium) discusses the Debian way to install a framework or a set of libraries, where it adds value, and where it needs administering.
Setting up secure remote support options (Simple) goes through the simple but necessary changes, necessary on a Debian system, in order to facilitate a more secure working environment.
Keeping your system up-to-date (Simple) teaches us that with thousands of developers maintaining the most exciting open source projects, it’s important to know how to and when to install updates on Debian.
Backing up your environment (Medium) describes a backup and restore strategy from an outcome-oriented vision using simple tools and dedicated backup software.
Restoring your environment (Simple) discusses the scenarios where fast restoring of data is critical to the application.
Preparing for common security scenarios (Medium) tackles several of the most common security scenarios and how to move from reactive to proactive security.
Reading logs and troubleshooting your setup (Simple) goes through the most important logfiles and essential skills to troubleshoot, by interpreting them.
Using proxies, caches, and clusters to scale your architecture (Advanced) discusses architectural scenarios for future growth of the application, including proxies, caches, and clusters, and when they can add value.
Consuming Windows Azure Cloud Services (Medium) provides a specific example of how to consume public cloud services for extending the application.
Responding to security incidents (Advanced) discusses several steps and outcomes in the face of a security incident.
Monitoring your server’s operation (Medium) goes through several of the most common data points for a web-based application, and how to collect, compare, and process them.
Optimizing your solution performance (Advanced) discusses not only the low-hanging fruit for web application performance improvement, but also the potentially bigger improvements of fundamental debugging and optimization.
You need hardware, either a server or hypervisor software that supports Linux-based operating systems to install Debian. You should plan for at least 2 GB of disk space, and additional space for your database and application, including static files. You also need a broadband Internet connection to download the installation media as well as any additional software packages.
Readers should be familiar with the essential concepts of the Linux system’s administration, such as how to work with files and permissions, command line instructions, and how service and processes work in Linux, although the chapters are not technically demanding. While the book does not require previous knowledge on the APT system, it does expect readers to understand how the particular configuration files for the services Apache, Nginx, MySQL, PostgreSQL, and so on, work.
In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.
Code words in text are shown as follows: “You can always delete those partitions and give space back to
A block of code is set as follows:
<?php $mc = new Memcached(); $mc->addServer(“localhost”, 11211); $value = file_get_contents(‘/var/www/icon.jpg’); $mc->set(“/icon.jpg”, $value); ?>
Any command-line input or output is written as follows:
chown –R www-data:www-data /var/www # resets owner and group to www-data
New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: “. You might choose Graphical Install, which will run you through the same prompts but with mouse support, colors, buttons and scrollbars.”.
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