A brief introduction to Docker
This brief introduction looks at exactly what Docker is, how it differs from virtual machines, and why it's experiencing such fast-growing popularity.
- August 7, 2017
What is Docker?
In short, Docker is “an open platform for distributed applications for developers and sysadmins”.
Let’s look into that in a little more detail.
Embraced by everyone from big open source names like Red Hat to proprietary software companies such as Microsoft, Docker has made a name for itself as potentially the most popular alternative to virtual machines.
Docker is a container that wraps up a piece of software in a complete filesystem that contains everything it needs to run. This means anything that can be installed on a server – code, runtime, system tools, system libraries – is in one place, meaning your software will always run the same, regardless of its environment. It allows for multiple instances of the same application, and it won’t throw up any surprises – potentially saving data centres and cloud providers millions in power and hardware costs!
Docker vs. virtual machines
While they function very similarly, a Docker container is more efficient and portable than a virtual machine. This is thanks to a different, more streamlined architectural approach.
VMs are essentially “emulating virtual hardware“, meaning they come with a lot of system requirements. This includes not just the application, but the necessary binaries, libraries, and its own guest operating system. Containers, on the other hand, use shared operating systems – they include the application and its dependencies, but run as an isolated process in userspace on the host operating system.
Image via docker.com
The upshot of this is that with a perfectly tuned container system, it’s possible to have up to 6 times the number of server application instances as you can with VMs. They’ll start instantly, make more efficient use of RAM, and make disk usage and image downloads a lot more efficient.
The rise of Docker
What is it that makes Docker containers such a popular choice for developers?
- It’s lightweight and offers an added layer of security
- Based on open standards – this means containers can run on all major Linux distributions and Microsoft operating systems and eliminates environment inconsistencies
- There’s support for every infrastructure thanks to Docker now bringing standardization to containers
- Instant application portability – Docker can be incorporated into most DevOps applications, is easy to deploy to the cloud, and is perfect for collaboration via the Docker Hub
- Developers using Docker ship software 7 times faster than those who don’t, while issues are easy to identify and isolate, minimising disruption
- Scalability – spin containers up and down as needed in seconds to satisfy peak customer demand
In summary
By and large, Docker functions the same way a virtual machine does, although it can’t use different operating systems or kernels the way a VM can. Its speed allows users to accelerate the onboarding of new developers, be more creative without worrying about conflict, and makes managing and deploying applications a lot easier.
At Clearvision, we use Docker in our Spectrum development – it gets our thumbs up, and we’ve seen first hand how Docker’s features all combine to make Docker ideal for the Enterprise. To learn more about Enterprise-level software development and scaling for the Enterprise, simply get in touch!
clearvisionwebmaster
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