Infrastructure as a Service Environment

In the previous step, we looked at a brief overview of three different types of environments. In this step, we will discuss Infrastructure as a Service Environment in a bit more detail.

Infrastructure as a service (IaaS) refers to an instant computing infrastructure that is provisioned and managed over the internet.

IaaS helps you avoid the expense and complexity of buying and managing your own physical servers and other datacenter infrastructure. Each resource is offered as a separate service component, and you only need to rent one for as long as you need it. A cloud computing service provider, such as Microsoft Azure, manages the infrastructure, while you purchase, install, configure, and manage your own software—operating systems, middleware, and applications.

Deciding whether to choose IaaS environments over the platform as a service (PaaS) will depend on the type of application, dependencies, and architecture. It is easy to perform a lift-and-shift (move an application from an on-premises VM to a hosted VM) for your application in IaaS, and it is very likely the fastest way to get your application into the cloud or hosted elsewhere. However, although it is easy to scale up by adding capacity to the host machine, it is not easy to scale out to run your application on multiple machines with IaaS. Applications also become entangled with the OS, making the task of migrating applications between operating system (OS) versions very risky without fully testing on a new OS version.

One way to think about whether to use Infrastructure as Code and IaaS environments are to consider scaling machines. If you need to add machines by scaling to (x), you likely will want to use Infrastructure as Code with IaaS environments.

Azure IaaS provides a range of options for developers looking to build directly on the operating system:

• Virtual machines – Azure provides a wide range of Windows Server and Linux based operating system image.
• Virtual Machine Scale Set – Virtual Machine Scale Sets provide an easy to use a slider-based mechanism for scaling identical groups of stateless virtual machines.
• Azure Container Service – Container Service is a fully open-source-based service that provides deployment, orchestration, and failover for Docker-based images across a cluster of virtual machines, by using Apache Mesos, Mesosphere’s Marathon, or Docker Swarm.
• Azure Marketplace – Azure Marketplace includes many popular application platforms or PaaS platforms in virtual machine images that you can operate and manage for yourself, including Pivotal Cloud Foundry.