Introduction:
With virtualization, applications are now deployed in a flexible manner that provides efficiency. In this blog post, we'll explore the key differences between two popular virtualization technologies: Virtual Machines (VMs) and Docker. These are the essential technologies when it comes to choosing an application infrastructure and this applies to both experienced developers and those that are just starting out.
Defining Virtualization:
Essentially virtualization is about using software and creating an abstraction layer. A hypervisor facilitates this abstraction for VMS, and emulates a physical computer for the VMMs. This means that each VM has a dedicated operating system in addition to virtual hardware. However, a free platform known as Docker uses containerization to package up the apps and all their dependencies and make them transportable. Unlike VMs that are virtualized at the OS level, Docker’s containers are lightweight because they themselves virtualize the OS thus offering an efficient solution.
Components Breakdown:
Docker Components:
Docker Engine: Manages the lifecycle of Docker containers, handling tasks like creation, running, and orchestration.
Docker Images: Lightweight, standalone packages containing everything needed to run software.
Docker Containers: Instances of Docker images, offering isolated and self-sufficient environments for specific applications.
VM Components:
Hypervisor: Software responsible for creating, managing, and running virtual machines. Types include Type 1 (bare metal) and Type 2 (hosted).
Virtual Hardware: Emulated components such as CPU, memory, storage, and network interfaces.
Guest Operating System: The operating system running inside each virtual machine, providing flexibility for diverse environments.
Use Cases and Considerations:
VMs:
Diverse Operating Systems: Ideal for testing applications across multiple platforms.
Isolation: Offers inherent isolation as each VM runs its own kernel and operating system.
Legacy Applications: Well-suited for running applications requiring specific OS versions or configurations.
Docker Containers:
Microservices: Perfect for managing microservices-based applications due to their lightweight nature and fast startup times.
Rapid Development: Enables agile development practices and CI/CD pipelines.
Resource Efficiency: Shares the host kernel, leading to a smaller footprint and efficient resource utilization.
Conclusion:
It is not all that clear if one should go for Docker or simply use VMs. Your option will be determined by the unique requirements of your applications and infrastructure. Hybrid environments often occur where VM hosts old legacy applications while Docker containers manage current microservices. Virtualization technologies are continuing to transform how we deploy and manage applications into another new wave of changes in technology space.