Docker in DevOps: Igniting Application-Wide Quality at Speed

DevOps has now become a de-facto standard for software development. The modern age of instant customer satisfaction has pushed market demands and competitive pressures to an all-time high.

Beyond that, end-users’ tolerance for brick and mortar applications has grown increasingly narrow. Thus, real-time application delivery has become a new norm.

Irrespective of the business case or industry, for every organization offering quality at speed and agility is the need of the hour. The entire business delivery ecosystem is shifting to the digital landscape, forcing leading enterprises to rely heavily on software applications to win, serve, and retain their customers.

Organizations are under tremendous pressure to reimagine and optimize their business operations and to be prepared for what comes next- to react faster, work better and deliver greater value. This is possible due to the advent of container technology known as Docker.

Docker: Powering Microservices with Automation

Docker, the de-facto toolset for DevOps, emerged into the DevOps world as an open source platform that uses OS-level virtualization to deliver software in packages called containers.

For instance, a snippet of code developed in java on your local system cannot run on another system or environment. This is due to different configuration settings in both the systems. Before deploying code in a different environment, it is inevitable to make changes in the configuration. However, that is quite tedious and vexing.

Docker helps overcome such issues. Each container is isolated from the other having its own package containing software, libraries and configuration files. This allows containers to communicate easily through well-defined channels. They enable the reliable running of any software irrespective of any computing environment and without any compatibility issues.

Whether the software application is moved from a developer’s desktop to a test environment or into production, or in a data center to any virtual machine in a public or private cloud, Docker makes it work just fine. That’s why Docker has gained enormous popularity due to its lightweight, agile, and standardized nature.

Some of the enterprise leaders have already deployed Docker containers for a variety of mission-critical applications, for example:

Pinterest — Deployed Docker to improve the production Machine Learning Systems powering their home feed.

GE Digital — Leveraged the Docker platform to repackage one of their on-premise solutions and embrace a new fog computing approach with greater intelligence and more computing power.

GlaxoSmithKline — The global pharmaceutical company is using Docker Enterprise Edition to help power its new research environment for identifying new medical discoveries more rapidly.

MetLife — Used Docker for legacy application modernization and observed savings of 66% across nearly 600 of its applications.

Dockers are the perfect vessels to encapsulate microservices, enable portability between on-premises and cloud, and push through continuous integration/continuous deployment (CI/CD) pipelines.

“It is estimated that 75% of global organizations will be running containerized applications by 2022”

– Gartner

Docker boosts efficiency with your existing applications while dramatically reducing capital and operational efficiencies and improving developers’ productivity. It can set the groundwork for future innovation reducing the infrastructure and maintenance costs while accelerating your time to market for new solutions.

Docker Architecture

Let’s understand Docker’s architectural components and their inter-relationship.

• Docker Client is an interface that enables users to interact with docker daemon using REST API to provide build issue, run and stop application commands to a docker daemon.
• Docker Daemon is a background process that handles the request of storing images, creating, running and monitoring containers from the host machine.
• Docker Registry contains docker repositories of docker container images that can be stored and downloaded through public and private access permissions.
• Docker File contains instructions to build a Docker image.
• Docker Image is a read-only binary template and contains a set of parameters to build containers or customize to add additional elements to extend the current configuration.
• Docker Containers are encapsulated environments to run applications. One can create, run, stop, move or delete the container defined based on the image using Docker API or command line.

How Docker Fits into the DevOps Landscape

Docker is an important part of the DevOps ecosystem. It is designed in a way to benefit the development and operations team, where the development team can focus on writing code without worrying about the system it will run. While docker gives flexibility to the operations team reducing the need for several systems due to its small footprint and lower overhead cost.

Docker enables developers to easily decouple applications from operating systems since it’s lightweight, portable and a self-sufficient container. It brings a refreshingly new flexibility in managing applications virtually anywhere.

Docker has been designed in a way that it can be incorporated into most DevOps applications, using continuous integration tools such as Jenkins, Puppet, Chef, and Vagrant to put orchestration in place and enable continuous deployments.

For example, Docker integration with CI tool — Jenkins, follows the below steps:

• Jenkins will fetch Docker file from Git and builds Docker image
• Docker Image is then stored in Docker Registry
• Jenkins can pull the docker image from the Docker registry and run the container
• Jenkins can start/stop or delete container using docker API or command line

Docker containerization helps organizations deliver software and services at an accelerated speed with development and operational agility.

This blog is originally published at Cygnet Infotech.