Containers 101 Part 1 - Getting Started with Containers

Introduction

Welcome to the first entry in our series dedicated to demystifying the world of containers. This introductory post, "The Road to Containers," aims to lay the groundwork by exploring how traditional IT infrastructure and server virtualization paved the way for the advent of container technology. Understanding this evolution is crucial for appreciating the significance and benefits of containers in today’s IT landscape. The parts of this series are also captured in the Containers 101 YouTube video, which is available on the Trainso YouTube Channel.

From Traditional IT Infrastructure to Virtualization

Working with Traditional IT Infrastructure

In the early days of IT, deploying an application was straightforward but cumbersome. If we needed to run an application, we purchased a physical server. This server required an operating system (OS), which we had to install and regularly update with patches. Installing our application and its dependencies was next, a process that had to be repeated on every server where the application was needed.

As our needs grew, scaling meant adding more servers and repeating the setup process, including configuring additional components like load balancers. This approach was not only resource-intensive but also led to potential resource utilization issues, especially when multiple applications were hosted on the same server.

The Shift to Server Virtualization

Server virtualization marked a significant shift in how IT resources were deployed and managed. By allowing multiple virtual machines (VMs) to run on a single physical host, it became possible to utilize resources more efficiently. This technology laid the groundwork for cloud computing by enabling the sharing of physical server resources among multiple virtual servers.

Hypervisors: The Enablers of Virtualization

Central to server virtualization are hypervisors, software components that manage VMs. There are two main types of hypervisors:

• Type 1 (Bare Metal): These hypervisors run directly on the host's hardware to control the hardware and to manage guest VMs. They are crucial for cloud computing environments.
• Type 2 (Hosted): These hypervisors run on a conventional operating system, providing a more flexible solution ideal for development and testing environments.

Examples of Hypervisors:

• Type 1: VMware's vSphere, ESXi, Microsoft Hyper-V, Oracle VM Server, and Citrix Hypervisor.
• Type 2: VMware Workstation, VMware Fusion, Oracle VirtualBox, and Oracle Solaris Zones.

The Problems That Led to Containers

Despite the advancements brought by virtualization, new challenges emerged. The need for even more lightweight and agile VM alternatives became apparent, especially for use cases requiring rapid start-up and shutdown times, such as serverless computing. Additionally, the notorious "It works on my machine" problem highlighted the need for consistency across development, testing, and production environments. The "It works on my machine" problem highlights the discrepancies between development, testing, and production environments, often causing conflicts where developers claim their code works fine on their setups, while testers face issues in their own environments.

Introduction to Containers

Containers emerged as a lightweight alternative to VMs, addressing many of the challenges previously faced. Unlike VMs, which include a full OS, containers share the host OS's kernel. This makes them more efficient and quicker to start. Managed by a container engine rather than a hypervisor, containers encapsulate an application and its dependencies, ensuring consistency across different environments and solving the "It works on my machine" problem.

The Benefits of Containers:

• Efficiency and Speed: Containers require less overhead than traditional VMs, making them ideal for high-performance and scalable applications.
• Consistency Across Environments: Containers package applications with their dependencies, ensuring they run consistently across all environments.
• Enabling Modern Architectures: Containers support architectural patterns like microservices, facilitating more modular and scalable application development.

Conclusion

The journey from traditional IT infrastructure through server virtualization to containers represents a significant evolution in deployment and scaling methodologies. By understanding this progression, we can appreciate the role containers play in modernizing application deployment and management. In our next posts, we'll dive deeper into container technology, including how to work with containers, orchestration tools, and best practices for containerized environments.

See also

You can read Part 2 of this series at buddytutor.com/blog/containers-101-part-2-containers-core-concepts.