Historically, IT infrastructure management was entirely a manual process. Infrastructure provisioning during the traditional IT era was quite an expensive and time-consuming process where expert personnel was
required to physically set up the servers, install and configure the operating system software, and then connect the networks, middleware, and storage, etc., manually.
Infrastructure management has been a tedious full-time job for decades. But the problem of physically managing the hardware was overcome by technologies like virtualization and cloud-native development, which enabled the developers to provision their infrastructure like containers, virtual servers, etc., whenever required. For over the last ten years, managing the critical infrastructure has been revolutionized through the much appreciable services provisioned by cloud providers like Google, Amazon, and Microsoft for millions of their customers.
With the increase in the usage of cloud-native and public cloud platforms and accessibility & consumption of their provisioned infrastructure, everyone might have come across one of the most heard terminologies, i.e., Infrastructure as Code (IaC). Infrastructure as Code (IaC) solves all the traditional IT infrastructure configuration and management problems by enabling the developers to efficiently and effectively set up and provision a fully documented and versioned infrastructure by just executing a script, preventing the problem tracking environment changes and configuration inconsistency.
"If you’re going to do operations reliably, you need to make it reproducible and programmatic."—Mike Loukides, Vice President of Content Strategy for O'Reilly Media
Adopting the IaC approach can help organizations leverage various advantages at the infrastructure management level. The IaC approach's adoption has thus matured gradually and taken hold within the industry to provide end-to-end coverage for the environments being setup and provisioned. This maturity ultimately resulted in the enthusiasm and acceptance towards the use of IaC in organizations
What is Infrastructure as Code(IaC)?
Infrastructure as Code (IaC) is the automation of infrastructure provisioning and management using software development principles and practices. It is all about managing the infrastructure through a high-level descriptive model using the same versioning that the DevOps team uses for the source code. Whenever an IaC model is applied, it generates the same environment, just like the same source code generates the same binary every time.
The idea is to treat your infrastructure like software. You need to write the code, test it, and execute it to set up, deploy, update, or delete the required infrastructure.
Once configured and deployed, you need to make changes to the Code and apply it to the systems after testing if you want to modify or update the respective infrastructure. With IaC, every time you build, test, or deploy your software application, you don't need to manually provision or manage the required servers, operating systems, databases, networks, storage, or any other infrastructure element.
Infrastructure as Code follows the principle of idempotence that makes sure that irrespective of the initial state of an environment, a single deployment command sets the target environment into the same configuration every time, thus enforcing consistency and preventing configuration drifts.
IaC is an essential DevOps practice that is used in conjunction with Continuous Delivery. With IaC, DevOps teams gain the ability to provision multiple on-demand and stable production-like test environments at scale. They can create and version the required infrastructure very easily and rapidly in the same way they version an application source code. Not only this, but they can also prevent serious deployment issues by tracking those infrastructure versions to avoid configuration inconsistency among the provisioned IT environments.
Adoption of IaC
In earlier years, when automation was not that popular in the market, an entire IT infrastructure setting used to be a sensitive and manual process. This process included people setting up the rack and stacks of servers physically. This hardware was then manually configured according to the operating system's settings in use and the requirements of the application to be hosted. And finally, the application is deployed onto the hardware. This was the traditional scenario to get the application launched for use.
This entire process was quite critical and time-consuming. Since it required the hiring of several specialists for the tedious setup and configuration work, it resulted in the overhead of human resources. Several human resources manually doing different setups mostly led to inconsistency and unwanted variance in the configurations. Not only this, but there was also a considerable amount of money and labor required for the setup and maintenance of large data centers needed to house all the hardware. Additionally, the high availability and scalability of the hosted applications was also a big problem that significantly impacted the organization's capability to serve and satisfy its customers.
All these problems were somewhat overcome and addressed through the advent of cloud computing. Cloud computing proved to be useful to solve capital and human resource overhead and the application's high availability and scalability. The configuration inconsistency persisted, where the manual setup of infrastructure over the cloud could lead to variance and discrepancies.
This is where the Infrastructure as Code came into the picture that basically provisions and manages your servers, networks, storage, and other infrastructure in the form of source code, rather than using the traditional manual processes or standard operating procedures. And this Code then helps you set up and deploy the parts of the infrastructure quickly and consistently.
How does it work?
Before moving on to the approaches of the implementation of IaC, let us first discuss a critical decision to be made while automating the infrastructure through Infrastructure as Code (IaC).
Immutable Infrastructure vs. Mutable Infrastructure
While automating the infrastructure through IaC and choosing an IaC solution for the same, you first need to decide whether you want to establish an immutable infrastructure or a mutable infrastructure.
Once you have provisioned infrastructure and later be modified or updated according to your needs, this kind of infrastructure is termed as mutable. Mutable infrastructure enables the software development teams to make impromptu server customizations and allows them to respond to any emergent security issue. But while talking in terms of IaC, mutable infrastructure undermines one of its key benefits -- that is, maintaining configuration consistency within versions and between deployments and environments; as a result, it makes version tracking difficult.
Overcome the above hassle by implementing IaC as immutable infrastructure, i.e., the infrastructure once provisioned cannot be modified or updated. In such scenarios, if the infrastructure needs to be changed, you don't update the existing infrastructure. Instead, you replace it with a new one, i.e., you roll out a new version of the infrastructure. This eliminates the issue of configuration drift and ensures consistency between different environments. Immutable infrastructure enables teams to easily maintain and track different infrastructure versions and roll out to a previous version, if necessary. Immutable infrastructure is thus more feasible and practical and strengthens all the benefits of IaC implementation.
Different approaches to Infrastructure as Code
After taking the above important decision of choosing what kind of infrastructure to establish, it is also important to decide on implementing infrastructure automation while choosing an IaC solution.
The declarative approach is the functional approach that is considered the best fit in most organizations. Suppose you want to spin up a virtual machine, then install and configure the required software, resolve the interdependencies of the system and the installed software, and then manage the software versioning too. You just need to specify this desired state of the final infrastructure you need to set up and provision and rest everything handled and managed by the IaC. This kind of approach is termed as the declarative approach. The only downside of this approach is that it requires a skilled, expert administrator specializing in setting up and managing such infrastructure.
The imperative approach is the procedural approach, which requires you to define specific steps through automation scripts to set up and provision the necessary infrastructure. This approach supports the existing configuration scripts that you already have, therefore making it easier for the current human resources to understand the process and adopt IaC. The only concern here is that this could become quite complex, and you might need to manage more work with this approach in scenarios where you need to scale.
Thus, after deciding on the required IaC solution suitable as per your needs, you just need to:
Define the configuration parameters for the infrastructure you want to provision in the Domain-specific language (DSL) in files called manifests
Send those manifests to a code repository or a master server
Use the IaC platform to create and configure the desired infrastructure as per the instructions defined in the manifests
There are many easy-to-use and popular IaC tools that help you perform this and automate the setup, provisioning, and management of the desired infrastructure.
Major Native IaC Providers
The top native IaC providers include Amazon Web Services(AWS), Microsoft Azure, and Google Cloud Platform(GCP). They are considered native providers of IaC because their offerings work best within their own cloud platforms.
IaC on AWS
Managing the entire AWS infrastructure using Infrastructure as Code through AWS CloudFormation brings automation to the manual provisioning process and enables the developers and administrators to instantiate the required infrastructure through configuration files. Read More
IaC on Microsoft Azure
Microsoft Azure enables its customers to easily manage the Azure resources by implementing and taking advantage of Infrastructure as Code through Azure Resource Manager (ARM). With ARM Templates, you can define the desired state of your infrastructure and achieve consistent results through the principle of idempotence. Read More
IaC on Google Cloud Platform
GCP provides Google Cloud Deployment Manager as its native infrastructure deployment service to automate the creation, configuration, and management of Google Cloud resources. The configurations for the desired infrastructure can be treated as code and the creation of resources that are defined through those configurations can easily be repeated over and over again by maintaining consistency. Read More
Key Benefits of IaC
Increase in Speed
Infrastructure automation through IaC allows you to quickly provision the desired infrastructure for development, staging, and production environments. With IaC, you can easily and rapidly spin up an entire IT infrastructure by just running an automation script. Traditional infrastructure setup and management was a time-consuming process but since IaC documents and codifies everything, therefore, you can experience an immense increase in the speed of configuration and environment provisioning.
IaC standardizes the process of infrastructure setup. Earlier, ad hoc configuration modifications resulted in configuration drifts between different IT environments being set up, which led to serious deployment issues and security risks while developing application software. IaC tends to prevent those drifts by generating the same target environments with the same configuration every time. IaC enforces consistency, reduces the possibility of errors and deviations, decreases the chances of infrastructure incompatibility, and ultimately helps the deployed applications run smoothly.
More Efficiency in Software Development
The productivity of developers increases with IaC into the picture, and thus, the software delivery lifecycle gets accelerated and becomes more efficient. With IaC, developers can rapidly get provisioned with their sandbox or CI/CD environments; the QA team can provision production-like stable test environments for thorough testing; the security team can quickly get their staging environment provisioned for user acceptance testing; finally, the entire infrastructure and application source code can be deployed to the production environment at one go.
Due to the ability to version the infrastructure manifests, it becomes very easy to configure the same environment whenever needed, thus using identical environments throughout the development process. All the configurations and related changes get automatically logged and documented. You gain the ability to easily audit and track those changes; thus, speeding up bug fixing, which in turn minimizes the risk of issues, ensures quality, and enhances the security of the application.
With IaC into the picture, the organizations reduce time and effort and make the whole process of infrastructure management cost-effective. The developers tend to be more productive, spend more time on valuable tasks like innovations, develop new features or solutions, and focus on serving their customers better
Infrastructure as Code Best Practices
Your Code acts as a single source of truth
Code is the core of IaC. You need to explicitly configure all your desired infrastructure as Code in configuration files. These configuration files then tend to act as the single source of truth for all your desired infrastructure specifications. With all your Code in place, your infrastructure can be rapidly and seamlessly deployed without having anyone to log into the server to make any manual adjustments. You also don't need to document anything regarding the state of the infrastructure; your Code takes care of everything, even the required documentation too.
Use of a Version Control system
All your configuration files should be stored under a version control system like Git, BitBucket, SVN, etc. With this practice in place, any modification done to the Code can be easily tracked and managed. Not only does this provide you the ability to version the Code and audit the code changes, but you can also collaborate and test the code before making it live.
Continuous Integration and Continuous Testing is important
Similar to the application source code, the Code for your desired infrastructure should also be managed through CI/CD. Automated tests should be set up to run every time a change is configured to the Code.
Continuous testing should be applied to the infrastructure configurations to ensure that post-deployment issues might not prevail afterward. Continuous monitoring should be set up to continuously detect threats and monitor the infrastructure's security throughout the development lifecycle.
Additionally, with a proper continuous integration process in place, you can deploy the configuration templates multiple times to provide and work on multiple on-demand environments with consistent configurations, thus, mitigating the risk of any potential errors.
Use of Modular Architecture
You should apply the concept of microservices architecture to IaC that enables you to break down the infrastructure into separate modules and then combine them through automation. This practice provides you with greater control over different parts of the infrastructure and lets you define who can access which part or module of your desired infrastructure. Each microservice has its own configuration template, which ensures more consistency within the infrastructure. You can also limit the configuration changes that can be made, thus speeding up the bug detection process and your team's agility.
Use of Immutable Infrastructure
Whenever possible, you should try to opt for an IaC solution that promotes the use of immutable infrastructure. It requires you to use a defined infrastructure multiple times and then altogether replace it when you need to have configuration changes or updates instead of changing the infrastructure configuration in-place. This avoids configuration drifts, provides consistency and improves security. Due to little or no configuration edits, developers can track changes and troubleshoot an easier process.
Infrastructure as Code is thus a crucial part of DevOps. It can be treated as the next logical step after cloud computing towards overcoming the existing traditional IT infrastructure provisioning and management issues. Undoubtedly, organizations can adopt infrastructure automation through Infrastructure as Code (IaC) and decrease costs and manual labor, including human-prone errors and risks. IaC is just an easy-to-implement framework that uses coding techniques to set up and manage the desired infrastructure effectively and efficiently.