Get an idea of the Docker Container
Docker is a tool that uses containers to make creation, deployment and running of application a lot easier.
It envelopes the application along with all other elements like external libraries and other such dependencies which are required to run the application into a single package smoothly.
This enables the application to run on any Linux machine irrespective of the custom settings of the machine which may be different from the machine where it was coded and tested.
It is an open source which means that anyone can add features and functionalities to meet their needs thus contribute towards the betterment of the tool.
The tools are designed such that it is making its way into the DevOps ecosystem. It helps the developers by assisting them to focus only on the development without being concerned about the system on which the code is going to run.
They can use one of the several programs already designed to run on Docker as a template for their application. Docker enables the IT operation team to set up an environment that replicates the production server and allows everyone to work on projects with the same setting irrespective of the local environment.
Docker though in a way is quite similar to the virtual machine, but unlike a virtual machine, it does not have a whole operating system in it.
Dockers utilize the Linux Kernel of the system they are hosted on and only require the application along with its dependencies to be packaged. This significantly reduces the size of the package and improves the performance by using lesser resources.
Companies Adopting Docker
Several enterprise-level organizations are using Docker in different ways.
GE’s initial application development practices were entirely manual and took on an average of 6 weeks to go from development to production on account of several mistakes, reworks, and reviews of the application.
There was no repeatability due to manual intervention. This issue was resolved by adopting Docker which in several ways is much easier to use and highly portable which gave the ability to build once and run in any environment.
Previously they used VMware which allowed running one application in a VM, but with Docker, they could now run on an average 14 applications per container.
PayPal uses the commercial solution of Docker; this has not only enabled the developers with regards to the productivity and agility but also the infrastructure team regarding cost-effectiveness.
BBC News delivers online news which has over 80000 daily news items in English itself. It ran over 26000 jobs in different integration environment in a sequential manner which would result in wait times of about 60 minutes per job.
Docker eliminated this time lag problem for BBC by allowing jobs to run in parallel. It gave the developers the flexibility for continuous integration which resolved the fundamental issue of speed and volume.
Migrating to Docker has dramatically helped Lyft regarding testing and deploying functionalities independently along with the smooth interaction between the microservices.
Continuous integration enabled more efficient and quicker development and delivery.
Several other organizations like Business Insider, Groupon, Yelp, ADP, eBay, Expedia, Spotify, The New York Times, Oxford University Press, PayPal, Shopify, The Washington Post, Uber are among the other organization that has explored and adopted Docker in their IT infrastructure.
Common Docker Use Cases
Configuration Simplification: Docker can run on any platform with the help of its configuration without the actual overhead of a virtual machine.
It allows you to put the configuration file into the code and pass environment variables to cater to different environments. So that one docker image could be used in the different environment.
Code Management: The code travels through a different environment in its journey from development to production.
Each environment is having slight variation than the other. Docker eliminates this difference by providing a consistent environment, making the development and coding so much more comfortable.
Docker images being immutable they come with the advantage of having zero change in application environment from dev to production.
Improved Development Productivity: The two essential objectives in the development ecosystem, is to have the development environment replicate as close as possible to the production environment and next goal to get quality code delivered as soon as possible.
Docker allows the code to run in a container which reflects the production environment and unlike VM, docker has lesser overhead memory capacity wise which helps several services to run.
The other goal is achieved as we use the Docker’s shared volume for the application code to be available to the container from the host. This allows the developer to edit the source code from his platform and editor which will reflect on the running environment inside the Docker.
Isolation of Applications: There are cases where application isolation may be needed for example API servers which require different apache and a different set of dependencies.
Running API servers under different containers is much better way out.
Debugging Capabilities: Docker provides numerous tools that work well with containers, with the ability to insert checkpoints within containers and also different containers which are quite essential while testing applications.
Rapid Deployment: Docker containers can be created quite quickly which achieved as containers are not booting up an OS but just running the application.
Once set, they give you peace that once the code has worked, it will work in all environment.
Docker with its vast benefits is becoming a valuable addition to the IT infrastructure.
If you are a system administrator or interested in learning this hot technology for career growth, I would recommend taking Docker Mastery online course.