Infrastructure as a Code (IaC)

Infrastructure as code is the process of managing and provisioning computer data centers through machine-readable definition files, rather than physical hardware configuration or interactive configuration tools.

Problems solved by IaC

1 High price:?When setting up the hardware and software, you need dedicated engineers. Supervisors are needed by network and hardware technicians, so there is more overhead management. With Infrastructure as Code, an ecosystem is set up by a centrally controlled tool. You pay for the resources you use, and you can scale up and down your resources easily.

2 Improved consistency:less ‘configuration drift’:?Configuration drift occurs when ad-hoc configuration changes and updates result in a mismatched development, test, and deployment environments. This can result in issues at deployment, security vulnerabilities, and risks when developing applications and services that need to meet strict regulatory compliance standards. IaC prevents drift by provisioning the same environment every time.

3 Accountability: Since you can version IaC configuration files like any source code file, you have full traceability of the changes each configuration suffered. No more guessing games about who did what and when.

Types Of Infrastructure

1 Mutable Infrastructure is the infrastructure that can be modified or updated after it is originally provisioned. Mutable infrastructure gives development teams the flexibility to make ad hoc server customizations to, say, more closely fit development or application requirements or respond to an emergent security issue. But, it also undermines a key IaC benefit—the ability to maintain consistency between deployments or within versions—and can make infrastructure version tracking much more difficult.

2 Immutable Infrastructure: infrastructure that cannot be modified once originally provisioned. If immutable infrastructure needs to be changed, it has to be replaced with new infrastructure. Because new infrastructure can be spun up quickly on the cloud—particularly with IaC—immutable infrastructure is much more feasible and practical than it sounds. Immutable infrastructure takes IaC to a next logical step, essentially hardening IaC to further ensure the benefits it offers. It all but eliminates configuration drift and makes it even easier to maintain consistency between test and deployment environment. It also makes it easier to maintain and track infrastructure versions and to confidently roll back to any version when necessary.

IaC Approaches

1 Declarative Approach: also known as the functional approach—is the best fit. In the declarative approach, you specify the desired final state of the infrastructure you want to provision and the IaC software handles the rest—spinning up the?virtual machine (VM) ?or container, installing and configuring the necessary software, resolving system and software interdependencies, and managing versioning. The chief downside of the declarative approach is that it typically requires a skilled administrator to set up and manage, and these administrators often specialize in their preferred solution.

2 Imperative Approach: also known as the procedural approach—it defines the specific commands needed to achieve the desired configuration, and those commands then need to be executed in the correct order.?

Types of IaC

Developers can choose from four main types of IaC, namely,

• Scripting:?The most direct path to IaC is writing scripts. Ad-hoc scripts are best for quick, short, or one-off tasks to be performed. However, it’s safer to use a more advanced solution for complicated setups.
• Configuration management tools:?These are advanced tools designed to handle applications, also known as code configuration. Normally, they concentrate on downloading and configuring servers. The Cook, the Puppet, and the Ansible are examples of these instruments.
• Provisioning tools:?Tools for provisioning concentrate on infrastructure creation. Developers can describe exact infrastructure components using these types of tools. Terraform, AWS Cloud Formation, and OpenStack Heat are all examples of this.
• Containers and templating tools:?These tools create pre-loaded templates or images with all the libraries and components necessary for running an application. It is easy to distribute containerized workloads and has a much lower overhead than running a full-size server. Docker, rkt, Vagrant, and Packer are examples.

Principles of IaC

• Easy reproducibility of the systems:?IaC should allow you to rebuild any given chunk of an infrastructure painlessly. This eliminates the uncertainty that may come in the form of danger or doubtfulness. And when it comes to delivering new services and environments, IaC builds trust.
• High-level flexibility:?There’s a need to ensure that all the questions your program asks have the answers to your Infrastructure. Such questions may be about several topics, ranging from the desired storage, linked network compatibility, and configuration. As versatile blocks that can be immediately assembled if and when the requirements occur, IaC should present itself.
• Dynamic Design:?Although it’s always a sure bet that a change in the form of an upgrade would require some part or another, it’s not always easy to make those improvements to the current structure. We can’t predict how a system’s requirements may change over time. That’s why one of IaC’s fundamental concepts is that there is always a shift in the design. So to be as lucid as possible, you can build your Infrastructure and applications.

Tools used in IaC

Puppet:

For IaC setup and automation, Puppet takes a more holistic approach. For many big businesses, such as Reddit, Dell, and Google, this tool operates the data centers and runs on all OS systems. It has one of the most sophisticated interfaces on this list, too. This tool uses DSL based on Ruby as the primary language for defining the Infrastructure’s desired end state.

Then the Puppet will work out the best way for you to reach the end state. It also tracks the system for any modifications that deviate away from the specified end state. It corrects those modifications automatically. This is a tool designed exclusively for system managers which offer substantial business and community support for credit.

Chef:

Among CI/CD professionals, Chef is a fairly common IaC method. It uses DSL based on Ruby, and this is definitely a big plus. From the outset, it has “cookbook” versions and helps you to maintain a consistent setup. Even when the Infrastructure has to keep up with the rapid development of the app that it hosts, this is possible.

At the center of its nature, the Chef offers recipes and cookbooks. There are self-styled template appellations and template sets you can use out of the box. A single task should usually be connected to one cookbook, but it can offer various server configurations depending on the resources involved. Chef also fits very well with other IaC platforms, including Terraform and many other cloud environments, since it supports cloud provisioning APIs.

Ansible:

Ansible is a system constructed from the beginning with the perspective of automation. This tool focuses on providing the configuration language “radically simple” and handling cloud instances instantly without modifications. It is also useful for arbitrary IT orchestration, such as zero downtime rolling changes, hotfixes, and so on, instead of being fundamental configuration management. You only explain how components and the system, in general, communicate with each other instead of handling systems as individual units, and Ansible can handle the rest.

Right now, Ansible is also one of the most versatile IaC resources on the market. You are not confined to the characteristics it offers. Instead, you can create your own modules and routines to suit particular needs. For setup and control, it also has an elegant Interface.

IaC best practices

• Use little or no Documentation:?In configuration files, define specifications and parameters. Additional documentation that gets out of step with the configurations in use is not required.
• Version control all configuration files:?Place all your configuration files under the control of the source. When handling technology, versioning gives flexibility and accountability. It also allows previous manifests to be monitored, controlled, and restored.
• Constantly test Configurations:?Until moving any changes to output, test, and control environments. Consider setting up automated tests to run if the configuration code gets altered to save time.
• Modular approach:?Divide the Infrastructure into different components and then, by automation, merge them. The segmentation of IaC provides many benefits. You also restrict the number of modifications to manifests that can be made.