Containers Crash Course Needed in Cape Town
Hello Sloan,
I just started a new job and everyone at my new company loves using containers. I am familiar with the concept on a basic level, but can you get me up to speed so I don’t sound like a total novice?
Thanks,
Containers Crash Course Needed in Cape Town
Hey there reader,
Containers can be complex and we certainly won’t cover everything you’ll need to know, but I can give you a quick overview of terms and concepts that you should know.
Containers Defined
The definition of a container is simple– it’s a package of software that has everything an application needs to run, including its dependencies. This includes things like libraries and configuration files. This means that a package in a container should be able to run in any environment.
According to a CNCF study from 2019, 84% of respondents were using containers in production. It sounds like your organization likely does as well.
The Benefits of Containers
A container holds all the information that a piece of software needs to run anywhere, and that’s a straightforward benefit in and of itself. Containers are very portable and can run in the cloud and on various operating systems.
Portability is not the only benefit, however. We talk a lot about DevOps here at Sonatype (we have some DevOps guides for those who want to learn more), and using containers can reduce the time and effort that it takes to deploy applications.
Running a container means that software and hardware are being separated (the software can live beyond the hardware it’s built on). Because of this, scaling in different environments becomes a much easier task.
The nature of containers also means that they can be hosted in public repositories, which makes sharing simple.
Less effort and time to deploy software means gains for both the development and operations teams, and the consistency of a container helps the entire SDLC (software development life cycle) progress smoothly.
Some Names You’ll See
As stated above, 84% of companies who responded to the CNCF survey in 2019 were using containers in production. 78% of respondents in the same CNCF Survey 2019 were using Kubernetes. You’ll see the word Kubernetes (or K8s) often because it’s heavily used open-source software that orchestrates containers and manages them as they are deployed. Kubernetes is also automatable and aids in scaling environments.
Another term you’ll see pop up a lot is Docker. You’ll see it come up in a variety of contexts, so let’s cover some:
- Docker- The most popular container software (others include Podman, Containerd, etc.)
- Docker Containers- A common and widely-used container format.
- Docker Server- A compute environment that hosts Docker containers.
- Docker Swarm- Software used to orchestrate containers, like Kubernetes.
- DockerHub- The most popular repository (open-source and closed-source) for Docker Containers.
It’s important to note that while it may seem like Docker and Kubernetes do the same thing, these tools are used together to deploy and manage container environments. If Docker containers are symphony musicians, Kubernetes is the conductor of the orchestra.
One Last Thing, Manifests
One last concept that is important to understand is a manifest.
Containers are most commonly created using manifests, which are like sets of instructions that tell software like Docker how to build the container. Because manifests dictate the installation process, this Configuration-as-Code or Infrastructure-as-Code gives developers control over how their applications are installed. This makes building containers automatable and repeatable.
The contents of a container are included in the manifest, so there is more visibility into the software itself. This can include easily adding changed details in version control in Github.
As a next step I encourage you to do some research on which tools your organization uses and ask questions about how they’re used.
That’s it for today! If you have any burning questions or comments for Sloan, drop them in the comments below.
Signed,
Sloan
~ Making Cyber a Safer Space