Entendendo "Devops" para Iniciantes em Programação (Parte 1) | Série "Começando aos 40"

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In this section, Fabio Akita introduces the topic of infrastructure and DevOps, highlighting his background in software development and occasional involvement with infrastructure. He emphasizes the importance of understanding DevOps beyond its surface definitions.

Introduction to Infrastructure and DevOps

• Fabio recommends watching previous episodes for beginners to grasp foundational concepts.

• Defines DevOps as a complex term often misused, emphasizing it is more than just tools or methodologies.

• Expresses the challenge of defining DevOps comprehensively due to its multifaceted nature.

Exploring Infrastructure Complexity

This part delves into the vastness of infrastructure, highlighting the intricate components and diverse areas within the field.

Understanding Infrastructure Diversity

• Acknowledges the vastness of infrastructure where one can spend years without exploring all aspects.

• Differentiates between consumer-grade hardware and data center components in terms of reliability and performance.

Evolution of Internet Infrastructure

Fabio reflects on the historical evolution of internet infrastructure, detailing challenges faced in earlier times.

Historical Perspective on Internet Infrastructure

• Emphasizes reliability and security as paramount in infrastructure operations.

• Recalls early internet days when companies bought servers or used home PCs for online presence due to limited options.

Web Server Configurations

Discusses web server configurations, focusing on Apache setups and virtual hosts.

Insights into Web Server Setup

• Details Apache's functioning with forked processes for each request and configuration through virtual hosts.

Understanding the Evolution of Web Servers

In this section, the speaker discusses the evolution of web servers, starting from the late 1980s when personal computers were not common, to the emergence of multi-user systems like UNIX and Linux that allowed for shared resources and tasks.

Evolution of Web Servers

• The transition from mainframes to UNIX systems enabled multi-user capabilities, paving the way for platforms like Linux to support multiple users and tasks simultaneously.

• User-level isolation in operating systems, coupled with the affordability of servers and their ability to handle multiple users concurrently, led to the rise of PCs running Linux with features like preemptive multitasking.

• The introduction of PHP popularized user-friendly management panels such as cPanel (1996), enabling users to manage databases, configure virtual hosts, and host applications efficiently.

• The LAMP stack (Linux, Apache, MySQL, PHP) became a prevalent technology stack for web servers. This standardization facilitated service offerings by companies leading to shared hosting services like Locaweb or Godaddy.

• Shared hosting services divided server resources among numerous small websites due to their low traffic demands. This model fostered an ecosystem for small agencies and freelancers to develop websites rapidly.

Challenges in Early Web Server Security

This segment delves into the security challenges faced by early web servers due to lax security measures as they transitioned from closed environments like academia or government institutions to public internet exposure.

Security Challenges

• In the initial phase, only large enterprises maintained their servers locally or through co-location services. Security was minimal as most attention was on developing sites rather than infrastructure security.

• With servers becoming accessible on the internet, hackers exploited weak security practices prevalent at that time. Lack of robust sysadmin knowledge made servers vulnerable to attacks through methods like brute force hacking using rainbow tables.

Understanding the Evolution of Web Hosting Technologies

In this section, the speaker delves into the early days of web hosting technologies, focusing on the challenges and vulnerabilities faced with Apache servers and PHP scripts.

The Vulnerabilities in Early Web Hosting Technologies

• Apache servers accessing user files for serving on virtual hosts led to security vulnerabilities.

• Issues with components like mod_php allowed unauthorized access to process memory, posing risks in shared hosting environments.

• Dilemma between performance and security: mod_php was performant but insecure, while FastCGI was safer but consumed more memory per user site.

• Shared hosting limitations: users had to create lightweight apps due to memory constraints; uploading content via FTP was the norm.

Advancements in System Resource Partitioning

This part discusses advancements in system resource partitioning technologies like "Jails" and their evolution over time.

Evolution of System Resource Partitioning

• Introduction of "Jail" concept in FreeBSD (2000), allowing isolation of processes within partitions for enhanced security.

• Linux VServer (2001): Similar to Jails, aimed at restricting process capabilities to prevent system crashes caused by malicious or faulty processes.

• Solaris containers (2004): Introduced zones for limiting system operations, setting a benchmark alongside ZFS filesystem.

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In this section, the speaker discusses the evolution of machines and the concept of time-sharing in computing.

Evolution of Machines and Time-Sharing

• Mainframes were initially expensive and inaccessible, leading to time-sharing where multiple users utilized machine pauses for computation.

• Mainframe researchers partitioned machines to run multiple kernels simultaneously, enhancing efficiency with each virtual machine having its own resources.

• Advancements in the 90s allowed for more powerful and accessible machines, paving the way for concepts like virtualization inspired by mainframe practices.

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This segment delves into the concept of virtualization and how it deceives processes akin to Descartes' evil demon or Plato's Allegory of the Cave.

Virtualization Concept

• Processes make syscalls with normal processes restricted to Ring-3, unable to access Ring-0 functions exclusive to kernels.

• Virtualization involves responding with deception; a special program lies about accessing hardware, akin to manipulating perceptions in philosophical analogies.

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The discussion shifts towards comparing brain functions with computer operations and introducing hypervisors as supervisors of supervisors.

Brain Analogy and Hypervisors

• Drawing parallels between brain IO functions and computer senses, highlighting how a special program deceives processes similar to brain perception manipulation.

• Introducing hypervisors as supervisors managing machine resources efficiently; distinguishing between Type 1 installed on bare metal and Type 2 running over an operating system.

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This part explores the challenges of simulating CPUs within hypervisors, emphasizing resource management complexities.

CPU Simulation Challenges

Virtualization and Hypervisors

In this section, the speaker discusses the concept of virtualization, hypervisors, and the evolution of virtual machine technology.

Understanding Virtualization

• Virtualization involves creating virtual instances of operating systems within a physical machine.

• Full virtualization simulates an entire machine, allowing different operating systems to run independently.

• Paravirtualization involves modifying operating systems to access hypervisor interfaces for improved performance.

• Paravirtualization requires collaboration between the OS and hypervisor for efficient operation.

• Certain hypervisors like Xen require specific OS versions with patches for paravirtualization.

Hardware Support for Virtualization

This section delves into hardware extensions by AMD and Intel to enhance virtualization performance.

Hardware Enhancements

• AMD introduced AMD-V and Intel introduced VT-X with new instructions for improved virtualized system performance.

• These instructions enabled virtualized systems to achieve near-native performance levels in various applications.

Advancements in Virtual Infrastructure

The discussion focuses on advancements in hypervisors and their impact on data centers.

Evolution of Virtual Infrastructure

• By 2005, hypervisors allowed running multiple OS simultaneously on bare metal or a host system.

• VT-X and AMD-v instructions facilitated efficient virtual infrastructure deployment in data centers.

• Virtual Private Servers (VPS) automated server provisioning, reducing costs and resource wastage.

Challenges in Managing Multiple Servers

Addressing challenges faced by enterprises managing complex server environments.

Server Management Issues

• Automation through VPS simplified individual server setup but posed challenges for large-scale enterprise management.

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In this section, the speaker discusses the challenges of dealing with certain technologies related to server management and introduces the concept of configuration management tools like CF Engine.

Technologies and Configuration Management Tools

• CF Engine 3 is highlighted as a significant tool for system administrators working with multiple servers, offering automation capabilities.

• CF Engine operates using a declarative language to describe server configurations, ensuring consistency and efficiency in installations.

• Configuration management tools like CF Engine, Puppet, and Chef streamline infrastructure management by enabling code-based descriptions of systems.

• Puppet and Chef are introduced as tools that allow describing infrastructure as code, promoting standardization and collaboration within the community.

• These tools follow a client-server architecture, facilitating the provisioning of new machines through agent processes listening for commands from a central server.

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This section delves into the evolution of server configuration practices from manual setups to automated solutions like SSH and deployment tools such as Capistrano.

Evolution of Server Configuration

• The transition from manual server configurations to automated systems like SSH simplifies provisioning new machines by leveraging agents for streamlined setup processes.

• Challenges arise with early configuration management systems requiring multiple components for setup, hindering quick configuration for single machines.

• The shift from insecure protocols like Telnet to secure alternatives such as SSH enhances data protection during remote access operations.

• Adoption of secure protocols like SSH replaces vulnerable options like Telnet, FTP, SMTP with more robust encryption methods for improved network security.

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In this section, the speaker discusses different infrastructure configuration tools like Ansible, Fabric, Capistrano, CF, Puppet, and Chef. The comparison between complex client-server tools and simpler agentless tools is highlighted.

Infrastructure Configuration Tools

• Ansible, launched in 2015, evolved from Python's Fabric and Capistrano.

• Ansible is recommended for developers needing to deploy applications quickly on VPS with automated updates.

• Chef is suggested for managing multiple machines like web servers, databases, and caches.

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This part emphasizes the importance of ongoing infrastructure maintenance beyond initial setup. It stresses the need for automation to ensure security compliance and efficient machine deployment.

Infrastructure Maintenance

• Infrastructure management involves continuous OS updates, application upgrades, and security measures.

• Automation ensures consistent machine setup while meeting security standards.

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The speaker delves into the technological advancements and significant events in the early 2000s that shaped internet usage patterns and innovation acceleration.

Technological Evolution in Early 2000s

• Transition from internet chaos post-2001 to mass entertainment online with platforms like MySpace and Facebook.

• Rapid tech evolution post-mid 2000s due to key events like Netflix's pivot to streaming and emergence of social media giants.

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This segment explores the shift towards constant online connectivity driven by smartphones, social media platforms, and evolving internet technologies.

Online Connectivity Shift

• Proliferation of smartphones led to a desire for constant online presence impacting service scalability.

Detailed Discussion on Infrastructure Evolution

In this segment, the speaker discusses the limitations faced with tools like CF and Chef in managing configurations across a large number of machines. The need for new architectures due to the rapid evolution of web infrastructure from 2006 to 2015 is highlighted.

Evolution of Infrastructure Tools

• Tools like CF and Chef faced limitations in handling configurations across numerous machines.

• Challenges arose in scenarios where a large number of machines needed to access a server for configuration updates, potentially causing network congestion.

• New architectures had to be developed to address these scalability issues brought about by the increasing demands on web infrastructure.

Technological Advancements Leading to Docker and Kubernetes

This part delves into how technologies discussed earlier will eventually lead to innovations like Docker and Kubernetes, which have become prominent in the tech industry.

Impactful Technological Progression

• Technologies mentioned are foundational for advancements such as Docker and Kubernetes.

• Docker and Kubernetes are widely recognized technologies frequently discussed in tech blogs and events.