In this article by Ritesh Modi, the author of the book DevOps with Windows Server 2016, we will introduce foundational platforms and technologies instrumental in enabling and implementing DevOps practices.

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These include:

• Technology stack for implementing Continuous Integration, Continuous Deployment, Continuous Deliver, Configuration Management, and Continuous Improvement. These form the backbone for DevOps processes and include source code services, build services, and release services through Visual Studio Team Services.
• Platform and technology used to create and deploy a sample web application. This includes technologies such as Microsoft .NET, ASP.NET and SQL Server databases.
• Tools and technology for configuration management, testing of code and application, authoring infrastructure as code, and deployment of environments. Examples of these tools and technologies are Pester for environment validation, environment provisioning through Azure Resource Manager (ARM) templates, Desired State Configuration (DSC) and Powershell, application hosting on containers through Windows Containers and Docker, application and database deployment through Web Deploy packages, and SQL Server bacpacs.

Cloud technology

Cloud is ubiquitous. Cloud is used for our development environment, implementation of DevOps practices, and deployment of applications.

Cloud is a relatively new paradigm in infrastructure provisioning, application deployment, and hosting space. The only options prior to the advent of cloud was either self-hosted on-premises deployments or using services from a hosting service provider. However, cloud is changing the way enterprises look at their strategy in relation to infrastructure and application development, deployment, and hosting. In fact, the change is so enormous that it has found its way into every aspect of an organization’s software development processes, tools, and practices.

Cloud computing refers to the practice of deploying applications and services on the Internet with a cloud provider. A cloud provider provides multiple types of services on cloud. They are divided into three categories based on their level of abstraction and degree of control on services. These categories are as follows:

• Infrastructure as a Service (IaaS)
• Platform as a Service (PaaS)
• Software as a Service (SaaS)

These three categories differ based on the level of control a cloud provider exercises compared to the cloud consumer. The services provided by a cloud provider can be divided into layers, with each layer providing a type of service. As we move higher in the stack of layers, the level of abstraction increases in line with the cloud provider’s control over services. In other words, the cloud consumer starts to lose control over services as you move higher in each column:

Figure 1: Cloud Services – IaaS, PaaS and SaaS

Figure 1 shows the three types of service available through cloud providers and the layers that comprise these services. These layers are stacked vertically on each other and show the level of control a cloud provider has compared to a consumer. From Figure 1, it is clear that for IaaS, a cloud provider is responsible for providing, controlling, and managing layers from the network layer up to the virtualization layer. Similarly, for PaaS, a cloud provider controls and manages from the hardware layer up to the runtime layer, while the consumer controls only the application and data layers.

Infrastructure as a Service (IaaS)

As the name suggests, Infrastructure as a Service is an infrastructure service provided by a cloud provider. This service includes the physical hardware and its configuration, network hardware and its configuration, storage hardware and its configuration, load balancers, compute, and virtualization. Any layer above virtualization is the responsibility of the consumer to provision, configure, and manage. The consumer can decide to use the provided underlying infrastructure in whatever way best suits their requirements. Consumers can consume the storage, network, and virtualization to provision their virtual machines on top of. It is the consumer’s responsibility to manage and control the virtual machines and the things deployed within it.

Platform as a Service (PaaS)

Platform as a Service enables consumers to deploy their applications and services on the provided platform, consuming the underlying runtime, middleware, and services. The cloud provider provides the services from infrastructure to runtime. The consumers cannot provision virtual machines as they cannot access and control them. Instead, they can only control and manage their applications. This is a comparatively faster method of development and deployment because now the consumer can focus on application development and deployment. Examples of Platform as a Service include Azure Automation, Azure SQL, and Azure App Services.

Software as a Service (SaaS)

Software as a Service provides complete control of the service to the cloud provider. The cloud provider provisions, configures, and manages everything from infrastructure to the application. It includes the provisioning of infrastructure, deployment and configuration of applications, and provides application access to the consumer. The consumer does not control and manage the application, and can use and configure only parts of the application. They control only their data and configuration. Generally, multi-tenant applications used by multiple consumers, such as Office 365 and Visual Studio Team Services, are examples of SaaS.

Advantages of using cloud computing

There are multiple distinct advantages of using cloud technologies. The major among them are as follows:

• Cost effective: Cloud computing helps organizations to reduce the cost of storage, networks, and physical infrastructure. It also prevents them from having to buy expensive software licenses. The operational cost of managing these infrastructures also reduces due to lesser effort and manpower requirements.
• Unlimited capacity: Cloud provides unlimited resources to the consumer. This ensures applications will never get throttled due to limited resource availability.
• Elasticity: Cloud computing provides the notion of unlimited capacity and applications deployed on it can scale up or down on an as-needed basis. When demand for the application increases, cloud can be configured to scale up the infrastructure and application by adding additional resources. At the same time, it can scale down unnecessary resources during periods of low demand.
• Pay as you go: Using cloud eliminates capital expenditure and organizations pay only for what they use, thereby providing maximum return on investment. Organizations do not need to build additional infrastructure to host their application for times of peak demand.
• Faster and better: Cloud provides ready-to-use applications and faster provisioning and deployment of environments. Moreover, organizations get better-managed services from their cloud provider with higher service-level agreements.

We will use Azure as our preferred cloud computing provider for the purpose of demonstrating samples and examples. However, you can use any cloud provider that provides complete end-to-end services for DevOps.

We will use multiple features and services provided by Azure across IaaS and PaaS. We will consume Operational Insights and Application Insights to monitor our environment and application, which will help capture relevant telemetry for auditing purposes. We will provision Azure virtual machines running Windows and Docker Containers as a hosting platform. We will use Windows Server 2016 as the target operating system for our applications on cloud. Azure Resource Manager (ARM). We will also use Desired State Configuration and PowerShell as our configuration management platform and tool.

We will use Visual Studio Team Services (VSTS), a suite of PaaS services on cloud provided by Microsoft, to set up and implement our end-to-end DevOps practices. Microsoft also provides the same services as part of Team Foundation Services (TFS) as an on-premises solution.

Technologies like Pester, DSC, and PowerShell can be deployed and configured to run on any platform. These will help both in the validation of our environment and in the configuration of both application and environment, as part of our Configuration management process.

Windows Server 2016 is a breakthrough operating system from Microsoft also referred to as Cloud Operating System. We will look into Windows Server 2016 in the following section.

Windows Server 2016

Windows Server 2016 has come a long way. All the way from Windows NT to Windows 2000 and 2003, then Windows 2008 (R2) and 2012 (R2), and now Windows Server 2016. Windows NT was the first popular Windows server among enterprises. However, the true enterprise servers were Windows 2000 and Windows 2003. The popularity of Windows Server 2003 was unprecedented and it was widely adopted. With Windows Server 2008 and 2008 R2, the idea of the data center took priority and enterprises with their own data center adopted it. Even the Windows Server 2008 series was quite popular among enterprises. In 2010, the Microsoft cloud, Azure, was launched.

The first steps towards a cloud operating system were Windows Server 2012 and 2012 R2. They had the blueprints and technology to be seamlessly provisioned on Azure. Now, when Azure and cloud are gaining enormous popularity, Windows Server 2016 is released as a true cloud operating system. The evolution of Windows Server is shown in Figure 2:

Figure 2: Windows Server evolution

Windows Server 2016 is referred to as a cloud operating system. It is built with cloud in mind. It is also referred to as the first operating system that enables DevOps seamlessly by providing relevant tools and technologies. It makes implementing DevOps simpler and easier through its productivity tools. Let us look briefly into these tools and technologies.

Multiple choices for Application platform

Windows Server 2016 comes with many choices for application platform for applications. It provides the following:

• Windows Server 2016
• Nano Server
• Windows and Docker Containers
• Hyper-V Containers
• Nested virtual machines

Windows Server as a hosting platform

Windows server 2016 can be used in the ways it has always been used, such as hosting applications and providing server functionalities. It provides the services necessary to make applications secure, scalable, and highly available. It also provides virtualization, directory services, certificate services, web server, databases, and more. These services can be consumed by the enterprise’s services and applications.

Nano Server

Windows Server provides a new option to host applications and services. This is a new variety of lightweight, scaled-down Windows server containing only the kernel and drivers necessary to run as an operating system. They are also known as headless servers. They do not have any graphical user interface and the only way to interact and manage them is through remote PowerShell. Out of the box, they do not contain any service or feature. The services need to be added to Nano servers explicitly before use. So far, they are the most secure servers from Microsoft. They are very lightweight and their resource requirements and consumption is less than 80% of a normal Windows server. The number of services running, the number of ports open, the number of processes running and the amount of memory and storage required, also are less than 80% compared to normal Windows server.

Even though Nano Server out of box just has the kernel and drivers, its capabilities can be enhanced by adding features and deploying any Windows application on it.

Windows Containers and Docker

Containers are one of the most revolutionary features added to Windows Server 2016 after Nano Server. With the popularity and adoption of Docker Containers, which primarily run on Linux, Microsoft decided to introduce container services to Windows Server 2016.

Containers are operating system virtualization. This means that multiple containers can be deployed on the same operating system and each one of them will share the host operating system kernel. It is the next level of virtualization after server virtualization (virtual machines). Containers generate the notion of complete operating system isolation and independence, even though it uses the same host operating system underneath it. This is possible through the use of namespace isolation and image layering. Containers are created from images. Images are immutable and cannot be modified. Each image has a base operating system and a series of instructions that are executed against it. Each instruction creates a new image on top of the previous image and contains only the modification. Finally, a writable image is stacked on top of these images. These images are combined into a single image, which can then be used for provisioning containers. A container made up of multiple image layers is shown in Figure 3:

Figure 3: Containers made up of multiple image layers

Namespace isolation helps provide containers with pristine new environments. The containers cannot see the host resources and the host cannot view the container resources. For the application within the container, a complete new installation of the operating system is available. The containers share the host’s memory, CPU, and storage.

Containers offer operating system virtualization, which means the containers can host only those operating systems supported by the host operating system. There cannot be a Windows container running on a Linux host, and a Linux container cannot run on a Windows host operating system.

Hyper-V containers

Another type of container technology Windows Server 2016 provides is Hyper-V Containers. These containers are similar to Windows Containers. They are managed through the same Docker client and extend the same Docker APIs. However, these containers contain their own scaled down operating system kernel. They do not share the host operating system but have their own dedicated operating system, and their own dedicated memory and CPU assigned in exactly the same way virtual machines are assigned resources.

Hyper-V Containers brings in a higher level of isolation of containers from the host. While Windows Containers runs in full trust on the host operating system, Hyper-V Containers does not have full trust from the host’s perspective. It is this isolation that differentiates Hyper-V Containers from Windows Containers.

Hyper-V Containers is ideal for hosting applications that might harm the host server affecting every other container and service on it. Scenarios where users can bring in and execute their own code are examples of such applications. Hyper-V Containers provides adequate isolation and security to ensure that applications cannot access the host resources and change them.

Nested virtual machines

Another breakthrough innovation of Windows Server 2016 is that now, virtual machines can host virtual machines. Now, we can deploy multiple virtual machines containing all tiers of an application within a single virtual machine. This is made possible through software-defined networks and storage.

Enabling Microservices

Nano Servers and Containers helps provide advanced lightweight deployment options through which we can now decompose the entire application into multiple smaller, independent services, each with their own scalability and high availability configuration, and deploy them independently of each other. Microservices helps in making the entire DevOps lifecycle agile. With Microservices, changes to services do not demand that every other Microservices undergo every test validation. Only the changed service needs to be tested rigorously, along with its integration with other services. Compare this to a monolithic application. Even a single small change will result in having to test the entire application. Microservices helps in that it requires smaller teams for its development, testing of a service can happen independently of other services, and deployment can be done for each service in isolation.

Continuous Integration, Continuous Deployment, and Continuous Delivery for each service can be executed in isolation rather than compiling, testing, and deploying the whole application every time there is a change.

Reduced maintenance

Because of their intrinsic nature, Windows Nano Servers and Containers are lightweight and quick to provision. They help to quickly provision and configure environments, thereby reducing the overall time needed for Continuous Integration and deployment. Also, these resources can be provisioned on Azure on-demand without waiting for hours. Because of their small footprint in terms of size, storage, memory, and features, they need less maintenance. These servers are patched less often, with fewer fixes, they are secure by default, and have less chance of failing applications, which makes them ideal for operations. The operations team needs to spend fewer hours maintaining these servers compared to normal servers. This reduces the overall cost for the organization and helps DevOps ensure a high-quality delivery.

Configuration management tools

Windows Server 2016 comes with Windows Management Framework 5.0 installed by default. Desired State Configuration (DSC) is the new configuration management platform available out of the box in Windows Server 2016. It has a rich, mature set of features that enables configuration management for both environments and applications. With DSC, the desired state and configuration of environments are authored as part of Infrastructure as Code and executed on every server on a scheduled basis. They help check the current state of servers with the documented desired state and bring them back to the desired state. DSC is available as part of PowerShell and PowerShell helps with authoring these configuration documents.

Windows server 2016 provides a PowerShell unit testing framework known as PESTER. Historically, unit testing for infrastructure environments was always missing as a feature. PESTER enables the testing of infrastructure provisioned either manually or through Infrastructure as Code using DSC configuration or ARM templates. These help with the operational validation of the entire environment, bringing in a high level of cadence and confidence in Continuous Integration and deployment processes.

Deployment and packaging

Package management and the deployment of utilities and tools through automation is a new concept in the Windows world. Package management has been ubiquitous in the Linux world for a long time. Packing management helps search, save, install, deploy, upgrade, and remove software packages from multiple sources and repositories on demand. There are public repositories such as Chocolatey and PSGallery available for storing readily deployable packages. Tools such as NuGet can connect these repositories and help with package management. They also help with the versioning of packages. Applications that rely on a specific package version can download it on an as-needed basis. Package management helps with the building of environments and application deployment. Package deployment is much easier and faster with this out-of-the-box Windows feature.

Summary

We have covered a lot of ground in this article. DevOps concepts were discussed mapping technology to those concepts. In this we saw the impetus DevOps can get from technology. We looked at cloud computing and the different services provided by cloud providers. From there, we went on to look at the benefits Windows Server 2016 brings to DevOps practices and how Windows Server 2016 makes DevOps easier and faster with its native tools and features.

Resources for Article:

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Further resources on this subject:

• Introducing Dynamics CRM [article]
• Features of Dynamics GP [article]
• Creating Your First Plug-in [article]

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