What is infrastructure as code and what advantages and disadvantages does IaC have for building and managing cloud infrastructures? One thing is certain: IaC makes it easier to manage large, distributed systems and service-oriented architectures.
The cloud promises a lot. Instead of constantly updating and managing one’s own data center, there is computing and storage capacity at will. Who then wants to deal with server installations and upgrades? But complex multi-cloud structures no longer work with just a few mouse clicks. Especially as companies increasingly rely on the services of different IaaS providers at the same time.
Control hardware with software
That’s why cloud operators and cloud users are very concerned with automation. One solution: “Infrastructure as Code”. It’s about programming the management of the IT infrastructure like an app. The virtualized hardware is therefore controlled by software. New servers are up and running in no time at all because the code does the work. Storage, server and network resources are operational and scalable without manual intervention.
Infrastructure as script code defines, for example, how many and which servers are required, for example the number of CPUs or the RAM required. The code defines which software must be installed and configured on the server in advance, which data it accesses and which systems it must communicate with. Which databases belong to the infrastructure and how are the load balancers configured?
Manual management is prone to errors
Today, the infrastructure is usually managed via an administration portal. The demand is clicked together and made available and then not touched for a long time. But computer structures are more fast-paced, especially in the cloud. What the cloud user no longer needs, he switches off as quickly as possible to save costs. And users need computing capacity at short notice, often only for a few days or even a few hours. In addition, there are no longer large, bold and sluggish instances, but virtual, agile and lean servers. This can hardly be done manually without errors. Over time, each environment becomes a unique configuration that cannot be automatically reproduced. Inconsistencies between environments lead to deployment problems.
Script reusable for configuration
The idea of IaC is now to automate repetitive manual actions by having a developer write a script for them. This is done automatically whenever it is needed. For example, to power on and power off a virtual machine with a specific configuration. What is then available is reusable code that can be easily customized as needed. This makes it possible to rebuild the same infrastructure at a different time or place by running the same script again.
Based on program codes, an automated IT infrastructure can be set up within which all predefined resources exist. The entire infrastructure is thus software-defined, developed on the basis of code that is normally only known from the programming of applications. For example, IaC can install a MySQL server, verify if it runs MySQL correctly, create a user account and password, set up a new database and remove unneeded databases – all by code. When the team makes changes, it edits the source, not the target. This change is then quickly and easily made available to other systems.
IaC is therefore repeatable and prevents runtime problems caused by configuration changes. In addition, the degree of automation can be increased to almost 100 percent. No human interaction is required at the time of infrastructure deployment. In addition, the infrastructure is able to heal itself independently.
Easy updates and more compliance
An enterprise can also combine infrastructure as code with containers that abstract the application from the infrastructure at the operating system level. Because the operating system and hardware infrastructure is automatically deployed and the application encapsulated on it, these technologies complement each other for various deployment goals such as testing, staging, and production. So the benefits of encoding resources range from configuration enforcement, to simpler updates, to greater compliance.
Because everything is code, the IT operations team needs to understand how to write the code. So IT administrators need to understand code structure, syntax and design. And IT staff must learn to manage the infrastructure in the scripts and not change configuration settings in any other way. There will inevitably be cases where an admin changes a configuration directly on the server and then wonders why the server restores the configuration without warning. Any changes to the infrastructure must be made in the code that prescribes this deployment.
Version history always available
With infrastructure as code, enterprises can be confident that each device supports an application the way it is supposed to run. The documentation will not be out of date, because as soon as the IT administrator updates documentation, the server immediately follows the example. When administrators put infrastructure code under source control, every change is recorded and can be easily reversed. There are no more puzzles when something has changed. One look at the history of the versions is enough. If changes fail, you return to the old version, and the device also returns to its previous configuration.
Simplified auditing and security are further advantages of IaC. When an auditor needs reports on the state of a network, administrators must rush to write scripts that retrieve the desired information from servers – just to find that they are not properly configured. Once everything is defined in the code, IT operations can provide the auditor with a network diagram in the form of all server configurations.
Beware of configuration changes
Despite its advantages, IaC has potential disadvantages. It requires additional tools, such as a configuration management system. Errors can spread quickly across servers. Therefore, it is important to monitor version control and perform comprehensive pre-testing. If administrators change server configurations without adapting the IaC code at the same time, configuration changes may spread throughout the data center. It is therefore important to fully integrate IaC into system administration, IT operations and DevOps processes with well-documented policies and procedures.
Conclusion: Despite some drawbacks, IaC is the next generation of infrastructure management. Where previously several hours of work and personnel resources were required for the software provisioning cycle – from the developer to the system and database administrators to the tester – the one-off creation of a script is now sufficient. Those who fully implement IaC might wonder how they have ever managed their infrastructure differently.
Automated startup of virtual replacement machines
With Infrastructure as Code, a developer writes application code and configuration management instructions that trigger actions from the virtualization environment and other environments such as databases, appliances, testing tools, deployment tools, and more.
When new code is delivered, Configuration Management automatically creates a new virtual test environment with an application server and a database instance that accurately reflects the structure of the real operating environment.
This means that a cloud application is able to boot up more virtual machines on its own when more power is needed, or shut down unneeded virtual machines on its own. The same applies if a virtual machine fails. Then the application itself ensures that a virtual replacement machine starts up – completely identical to the failed system thanks to IaC. Manual recovery, on the other hand, leaves the doors open for a multitude of human errors.