The topic of containers is huge and can seem endless. You can keep learning more and more about it and yet feel it is not enough. As someone who is trying to get into DevOps, it can get overwhelming very easily. This blog can help you out with that issue.
We will tell you exactly what you need to know to get started on Containers, how to learn more about them to get your job done as a DevOps Engineer.
Let’s start with the why. Why do we need containers and what benefits do they give?
To understand this, we need to start from where it all began. Long back, when you wanted to test an application made for Windows, you would transfer the code to a Windows machine with the correct specification and test the application. The issue with that approach was that it was a slow process. Every time you needed to run something, you needed to create the right environment with the right OS and specs in it.
Then came VMs or Virtual Machines. As the name suggests, a VM is a virtualised machine sitting inside a regular machine. This allowed multiple VMs to be run on a single machine. It was a better solution. You could also save VMs and replicate them easily. Tools like Vagrant, VMware made it extremely easy to have, say, 10 Windows and 5 Linux VMs on your laptop.
But VMs were often heavy and had an undesired replication of OS libraries. Why should we set up 10 Windows VMs with the same specs to run the 10 versions of an application? If we could use the same OS and have another layer of virtualisation, that could eliminate the need for duplicate OS binaries. Enter, Containers.
What is a Container
A container is a virtualisation tool that sits on top of a host OS and packages everything that an application needs to run, like – runtime libraries and other dependencies. It controls the processes that interact with the underlying OS.
The containers are also much more efficient because they are highly configurable through short build files. Containerisation also help in isolating the application from OS, making them much easier to operate under different environments.
So let’s summarise how a Container differs from a VM:
- Containers are lighter than VMs. They only package together what is needed by the application it is hosting.
- VMs virtualise the hardware underneath. Containers virtualise the OS for the application.
- Since Containers share the OS kernel and are not emulating an entire OS, they use a fraction of the memory that VMs use.
Docker and Kubernetes are two very popular container-based technologies.
Age of Container dominance
Docker was one of the first popular container technologies. Today, Docker is one of the most prominent container technologies in the world. It is almost ubiquitous in the virtualisation world.
Kubernetes helps with Container Orchestration. Meaning, when there are a lot of containers for different applications or “micro-applications” (called microservices) – Kubernetes helps in creating, managing and configuring them better. With the rise in Cloud technologies, containers have become the go-to way to develop and deploy applications. Popular Cloud service providers like AWS, Azure and Google Cloud offer specific pre-configured containers so that developers can focus on development and not infrastructure supporting it.
Today’s Virtualization has also gone through a massive transformation. The Guest OSes of the VMs are not sitting on another OS, but something called a Hypervisor.
A hypervisor is a small layer that allows multiple operating systems to run alongside each other while sharing the same hardware resources. The server on which a Hypervisor sits is called a Bare metal server. The VMs sit on top of the Hypervisor.
Even with advancements in hypervisor technology, a Container is a lighter, more agile way of handling virtualisation. Containers will fit the use cases of most new-age applications and provide faster resource provisioning and optimisations.
How to take this learning forward
So this was a very brief overview of VMs and Containers. This is certainly not enough for you to get your job done in your role as a DevOps engineer. You need to know how to use them.
Free resources vs Structured learning
One way to continue your learning from here – is by consuming knowledge from the Internet – watching endless YouTube videos, reading random blogs etc.
The issue with this approach is that the Internet can provide you with outdated or wrong information. You will also take much longer to learn as you will need to figure out which info will help you more in your DevOps job. Joining a course like ours can get you ahead in the game in a structured way.
Getting hands-on practice
The other benefit of joining our course is that you will get to work on real projects and get hands-on practice of situations that you’ll face as a DevOps Engineer.
Imagine working as a DevOps engineer and struggling to increase the replica sets of your Kubernetes setup because you have never tried this on a live system before. Our course can quickly prep you for these with essential hands-on practice.
Our course also has an Industrial Training add-on if you wish to undergo a month-long training under industry experts in the US and UK.
Preparing for Interview
The last step after all your upskilling is to crack a DevOps interview. The London School of Emerging Technologies (LSET) has a course to help you with that. We have a Job Guarantee add-on in our program where we take you through a rigorous career development program, conduct mock interviews with you and put you in front of many prospective employers.
Either way, we hope you now understand that Containers play an essential part in a DevOps Engineer’s role.
Learn more about our comprehensive LSET DevOps Engineer Certification course.