The process of managing IT infrastructures doesn’t have be
to a full-time job anymore. Infrastructure as Code (IaC) can automate the
building, updating, deploying, and monitoring of environments that developers would
otherwise have to do by hand.
This helps teams spin up new infrastructure faster, more
consistently, and at lowered costs. It also helps with aspects of managing that
infrastructure through version control, incremental deployments, and design
patterns.
For example, IaC defines where new infrastructure is
deployed (ex: public cloud), the type of service it will run on, and the
settings and security that should be enabled. The deployment models are
repeatable and can be easily scaled, changed, tracked, and tested to make
deploying and managing infrastructure as consistent and error-free as possible.
It’s no wonder more businesses are adopting Infrastructure as Code to
capitalize on these benefits.
How Does
IaC Work?
Typically, developers will write the infrastructure specs in
the domain-specific language, then files will be created from those specs and
sent to a master server, code repository, or management API. Finally, the IaC
platform will create and configure all computing resources to support the specs.
The code for the IaC tool is written in either a declarative
or imperative approach, depending on what you’re trying to accomplish. More
often, though, the declarative approach is used.
Declarative Approach
- Also known as functional approach
- Users provide directions to the automation
platform
- Users must know whether infrastructure already
exists, and its current state
- IaC defines the desired state of the final
solution
Imperative Approach
- Also known as procedural method
- Users specify the commands for change, which
must execute in the same order to reach the solution
- Users don’t know if the infrastructure already
exists
- IaC defines steps that must be implemented to
achieve the desired configuration
As you start out with Infrastructure as Code, you’ll want to ensure you’re approaching it in the best way possible. Here are three tips for success with your next IaC project.
Tip #1: Use
Immutable Infrastructure
As you work through your IaC strategy, it’s crucial to
establish whether you want the infrastructure to be mutable or immutable.
Something that is mutable is more easily changed, whereas something that is
immutable is not capable of change. So, which one should you use for IaC and
why?
Mutable
IaC Infrastructure
Mutable infrastructure must be updated and modified
continually to meet the changing needs of the business. In theory, it sounds
like the most flexible way to manage infrastructure for IaC. However, that
flexibility can be outweighed by other complicating factors.
Mutable infrastructure may lend itself to faster updates
since each update is adapted to each individual server. However, those
individual server updates are also part of the problem.
Every single server has a unique configuration, and changes
to those servers aren’t necessarily documented. So, it falls on one individual
in the IT team to get to know that server intimately in order to troubleshoot
and respond to issues.
Finding the issues themselves takes time, and then once they
are found, the IT member in charge of it must come up with viable solutions
instead of simply rebuilding the system to remove the quirks. If that person is
unavailable when a glitch happens, there’s no easy way to respond to the
issue.
This IaC infrastructure approach can become too complex over
time, making it more difficult to manage effectively. A lot of the work related
to mutable IaC must also be handled manually.
Immutable
IaC Infrastructure
Once immutable IaC is deployed, it can’t be changed. That
may sound scary, but it can actually lend itself to a more future-proof IaC
setup.
Components in immutable IaC must be built according to exact
specifications. If a change is required, the infrastructure must be rebuilt
according to the new requirements. Then, the old version is decommissioned.
This makes managing an immutable IaC much less complex,
because you’re not stacking a bunch of executable functions on top of each
other to provide a solution. All the steps and requirements of the change can
be easily documented and tracked by the entire IT team instead of relying on
one team specialist.
Hardware and software are virtualized using cloud computing,
and a continuous delivery pipeline automates the deployment and testing
requirements (since they’re predictable!) to get new applications
up-and-running faster. This is probably why more teams are pivoting from the
traditional model of mutable infrastructure to adapt immutable IaC for their
projects.
Tip #2: Use
a Version Control System
IaC files will need to be updated together with the IT
environment they help manage. A version-control system makes it easier to
track, manage, and restore any potential changes and document how the IaC has evolved
over time. Version control can also be useful for diagnosing issues and
reverting to an earlier IaC version if there’s a deployment issue with a new
version.
Tip #3: Make
the Definitions Modular
Remember at the beginning of this post when we mentioned that
IaC defines where new infrastructure is deployed, the type of service it’ll run
on, its settings, its security, etc.? While it may be possible to document all
of that in a single IaC file, a modular approach to storing that information
may actually be more helpful.
By breaking each aspect of the configuration into different
files, you make it easier to update one part of the configuration without
touching the other parts. In addition, it’s easier to control access to that
information to prevent inexperienced team members from altering the wrong
thing.
Modular IaC definitions are also helpful when you have
similar servers that are sharing SOME but not ALL of the same rules. For
example, two servers may require the installation of the same operating system,
but each one might have its own user accounts. Modular definitions would allow
you to create the files specific to each of those use cases, which cuts down on
confusion and ensures consistency.
IaC is the hot new approach to managing modern IT environments
and supporting successful DevOps. Keep best practices at the forefront to
ensure your IaC project is smooth, reliable, and scalable to your business.