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Infrastructure as Code Principles and IaC Adoption

Gursimran Singh | 12 Aug 2022

Infrastructure as Code Prinicples

Infrastructure as Code  Overview

The Infrastructure as Code (IaC) operations have modified how software developers develop, evaluate, and release applications by increasing the number of development and distribution cycles. To make infrastructure development and configuration more competitive and successful, reducing the costs and effort involved, automation tools that facilitate these activities are essential. 

As code, rather than physically configuring servers and operating systems, the infrastructure helps DevOps teams use technologies to manage and configure infrastructure. In version control systems, the modules can be processed, and operations teams run on them, allowing greater precision, eliminating errors, and reducing the time needed.

This blog illustrates and walks you through the major principles that Infrastructure as Code works upon.

6 Principles of Infrastructure as Code (IAC)

    1. Easily recreate systems
    2. Disposable Systems
    3. Self-Documentation
    4. Design Is Always Changing
    5. Generic Modules
    6. A single, unified API for automated infrastructure deployment

Easily recreate systems

The effortless and efficient rebuilding of any component of the infrastructure should be feasible. Effortless means that no meaningful decisions on how to rebuild the thing need to be made. Decisions like how to select a hostname, what applications and versions to install on a server should be captured in the scripts and resources that supply it, and so on. The ability to build and restore every part of the infrastructure effortlessly is essential. This eliminates much of the risk and fear while making changes. Failures can be complied with efficiently and confidently. With little effort, new services and ecosystems can be provisioned.

Disposable Systems

It is easy to build, destroy, upgrade, resize, and transfer resources when having a dynamic infrastructure. Systems should be designed in such a way as to take advantage of this to ensure that the infrastructure will still be developing. Even when servers disappear, appear, and are resized, the applications can stay running. The ability to manage changes makes it easier to make improvements and fixes to the infrastructure being run. This also makes services more failure-tolerant. This becomes particularly relevant when massive cloud infrastructure is shared, where it is not easy to guarantee the reliability of the underlying hardware. The change from unstable software, which relies on the hardware to be very stable, to software that runs reliably on unreliable hardware is a fundamental difference between the Iron Age and the Cloud Age.

Self-Documentation

The teams also struggle to keep their paperwork appropriate, helpful, and correct. Someone may write a detailed document for a new procedure, but as changes and adjustments are made to the way things are done, it is uncommon for such documents to be kept up to date. And records also leave holes regularly. Multiple people find shortcuts and changes of their own. To make aspects of the process smoother, some individuals write their scripts. 

Although documentation is often used as a means of maintaining continuity, norms, and even legal enforcement, it is a fictionalized version of what happens in reality. The steps for carrying out a process are captured in the scripts, definition files, and resources that execute the strategy with the infrastructure as code. To get individuals started, only a minimum of added documentation is required. The current documentation should be kept close to the principle that it records to ensure that when people make changes, it is close to hand and mind.

Design Is Always Changing

Making a change in an existing or legacy system is not only difficult but expensive. Thus, making limited changes makes sense. This leads to the need for comprehensive initial designs that take various possible requirements and situations into account. As it's difficult to predict how a system will be used or how the requirements will change over time, this approach of traditional IT systems creates overly complicated systems. This approach makes the new age agility difficult to achieve. 

With cloud-age dynamic infrastructure, making a change to an existing system can be easy and cheap. However, this assumes everything is designed to facilitate change. To satisfy current age needs, applications, and infrastructure must be built to be as basic as possible. The management of changes must be able to deliver changes safely and rapidly.

The most crucial measure to ensure that a system can be changed safely and quickly is to make changes frequently. This forces everyone involved to learn good habits for managing shifts, developing efficient, streamlined processes, and implementing tooling that supports doing so.

Generic Modules

Using the DevOps approach, we can create some new IT-style web and cloud-native applications and load them directly into the same environment that is used for the conventional software. That ensures that the IT operations team may handle the continuing lifecycle of new technologies for the production team. Developers are involved in writing and implementing new code; they are not generally as passionate about managing the software, operating systems, and underlying infrastructure. IT does not support cloud-based applications because developers end up being liable for the ops side of stuff, which is not their ability. IaC offers a Generic framework, allowing DevOps teams to continuously evolve and offer a natural way for IT to continue supporting the lifecycle of the application.

A single, unified API for automated infrastructure deployment

Since fluid resources are now served up IaaS-style, all you need is a single line of code that requests the compute capacity, network connectivity, and storage resources necessary to run a workload in production for that capacity to be dynamically allocated at runtime. This unified API gives developers to control and eliminates the time-consuming scripting associated with low-level tools and interfaces. Intelligent software handles the details, delivering precisely the right amount of computing, storage, and networking that the application needs.

The API manages physical objects in the same manner as virtual and containerized properties, so developers do not need a comprehensive understanding of the underlying architecture. The API is REST-based and provides language bindings for popular languages such as Java and Python in a composable infrastructure, enabling developers to access it directly from those languages. Also, the APIs typically integrate seamlessly into tools like Chef and Ansible, so developers can continue to use the DevOps tools they already know to deploy applications and associate them with the infrastructure.

 

How to embrace  Infrastructure as Code principles with Kubernetes?

  1. Idempotency - Idempotency decreases the inconsistency in Kubernetes cluster provisioning through IaC. It simply means that the start state of IaC should always end up with the same end state. For example, you have provisioned a three-node cluster using IaC. When you rerun the same Code, it should not provision 3 more (i.e., six nodes) nodes in the cluster.
  2. Immutability - Immutable IaC means - new infrastructure should be provisioned instead of modifying the same infrastructure. This decreases the chances of configuration drift in the infrastructure. For example, suppose you have two node Kubernetes clusters when you run your IaC again. In that case, it should shut down the previous cluster and create a new Kubernetes cluster.

What are the Infrastructure as Code  Principles for Kubernetes?

There are four Kubernetes IaC Principles. 

  1. Build Infrastructure Effortlessly
  2. Reuse the System
  3. Processes Are Repeatable
  4. Improved Reliability 

Build Infrastructure Effortlessly

Using infrastructure as code in Kubernetes, we can rebuild infrastructure effortlessly and reliably by creating different kubernetes manifest files.  To build an infrastructure run:  kubectl apply -f hello_world.yaml The hello_world.yaml is the Kubernetes manifest file which contains all the configuration required to build infrastructure using Kubernetes which means if we want to make any changes in the future we can do it by making changes in its manifest file. The ability to build any element of infrastructure is powerful. It removes much of the risk and fear when making any changes, as there is very little probability of human error.

Reuse the System

One of the advantages of dynamic infrastructure is that the resources of infrastructure can be easily destroyed, created, replaced, and moved. The application should continue running even when the server disappears and when it resizes. If we want to build infrastructure, then we can make use of the above kubernetes manifest file by updating its configurations according to our requirements and then applying the updated manifest file, which results in a newly built infrastructure.

Processes Are Repeatable

Building on the reproductive principle, any action we will perform on our infrastructure should be repeatable. This is one of the benefits of using configuration management tools and scripts rather than making changes manually. Still, it can be hard to stick to doing things this way, especially for experienced system administrators.

Improved Reliability 

All infrastructure is handled through the kubernetes manifest files and tools (kubernetes) that are responsible for implementing adjustments in infrastructure, so less risk of human error is present.

Infrastructure as Code Benefits with Kubernetes?

  1. Tracking and Auditability: IaC code can be stored in git repositories. Along with automation, it also acts as an infrastructure document. You can test the IaC code over the git repo and track who has made changes to the Code; if there is an issue, it can easily be tracked over git.
  2. Speed: Once all the required things are defined in the IaC, it allows you to provision Kubernetes clusters in both public and private clouds quickly, and also, you can deploy the containerized application on the provisioned Kubernetes cluster at lightning speed, which will increase quality and productivity of the application.
  3. Reusability: IaC code acts as a template; you can use it to provision Kubernetes clusters across various regions in the cloud. Along with this, you can deploy microservices on different Kubernetes clusters using the IaC.
  4. Consistency: No matter how hard you try, manual provisioning will still result in failure, but IaC will systemize the infrastructure provisioning and guarantee the same infrastructure over and over. Also, it will make sure that the microservice is deployed with the same configuration on the separate Kubernetes cluster.

Summary

The sign of an infrastructure team's effectiveness is how well it manages to change the requirements. Highly effective teams can control changes and new requirements easily, breaking down requirements into small parts and connecting them through a fast stream of low-impact variations. Every component of the infrastructure can be rebuilt quickly, with little effort. All systems are managed, patched, compatible, and up to date. Standard service requests can be met within minutes, including the provisioning of standard servers and environments, with no participation from members of the infrastructure team. SLAs are superfluous. 

Service windows are few if ever required. During working hours, adjustments take place, including software deployments and other high-risk operations. The team measures the recovery period (MTTR) and works on ways of enhancing it. While it is also possible to monitor the mean time between failures (MTBF), the team does not rely on failure avoidance. Members of the team believe that their task adds measurable value to the company.

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