Why Use Docker? Top 10 Reasons to Use Docker

Managing application dependencies and technology stacks across various cloud and development environments is challenging for DevOps teams. They ensure the application's reliability regardless of the underlying platform. Development teams focus on features of Docker and upgrades, but environment-dependent issues often arise during code deployment. To mitigate this, organizations increasingly adopt containerization frameworks. Docker, an open-source containerization technology, allows developers to write, operate, and bundle programs for container deployment. Unlike virtual machines, Docker provides:

• Abstraction at the operating system level with optimized resource usage
• Interoperability
• Build and test with efficiency
• Application execution that is faster
• Docker containers, at their core, modularize an application's functionality into several components that can be deployed, tested, and scaled independently as needed.

This article provides you the top 10 reasons of why use docker?

What is Docker?

Docker is a free, open-source containerization platform that allows developers to package applications into containers. These standardized executable components combine application source code with the OS libraries and dependencies needed to run the code in any environment. Containers simplify the distribution of applications and are increasingly popular as companies shift to cloud-native development and hybrid multi-cloud environments.

Containerization supports "write once, run anywhere" programs, enhancing portability and vendor compatibility. Containers are lightweight, sharing the machine's OS kernel and eliminating the overhead of associating an OS with each application. They have a lower capacity and faster start-up time than virtual machines, enabling more containers to run on the same computational power as a single VM, thereby improving server efficiency and reducing costs.

A Docker container includes an application and the necessary binaries or libraries. Docker, running on the OS (Windows 10, Windows Server 2016, or Linux), manages the container.

The following diagram depicts how containerized apps work.

Why Use Docker? Top 10 Reasons

Many of the users ask the most common question: Why use docker? The answer is, Containerizing programs have a variety of advantages which include:

1. Portability Across Machines

You may deploy your containerized program to any other system that runs Docker after testing it. You can be confident that it will perform precisely as it did during the test. 

2. Rapid Performance

Although virtual machines are an alternative to containers, containers do not contain an operating system (whereas virtual machines do), which implies that containers have a considerably smaller footprint and are faster to construct and start than virtual machines. 

3. Lightweight

Containers' portability and performance advantages can aid in making your development process more fluid and responsive. Using containers and technology like Enterprise Developer Build Tools for Windows to improve your continuous integration and continuous delivery processes makes it easier to provide the appropriate software at the right time. Enterprise Developer Build Tools for Windows is a component of Enterprise Developer that provides all of Enterprise Developer's features for compiling, building, and testing COBOL code without the need for an IDE. 

4. Isolation

Any supporting software your application requires is likewise included in a Docker container that hosts one of your applications. It's not a problem if other Docker containers include apps that require different versions of the same supporting software because the Docker containers are completely self-contained. 

This also implies that as you progress through the stages of your development lifecycle, you can be confident that a picture you create during development will operate identically in testing and, potentially, in front of your users. 

5. Scalability

If the demand for your apps necessitates, you can quickly generate new containers. You can use a variety of container management techniques when using multiple containers. For additional information on these choices, consult the Docker manual. 

6.Cost Savings

Docker contributes to cost savings through maximizing resource utilization via shared OS kernels, reducing hardware needs and enabling efficient scaling. Its rapid deployment and automation capabilities lower operational costs and minimize downtime. Docker's portability decreases troubleshooting expenses by avoiding environment-specific issues. Integration with CI/CD pipelines streamlines workflows, saving time and effort. By maximizing server usage, Docker reduces hardware and energy costs, while also improving software license efficiency. Consistent environments across development stages prevent costly errors.

To summarize -

• Docker is free and open source.
• It maximizes resource usage.
• It minimizes maintenance costs.

7. Multi-Cloud Platforms

Docker thrives in multi-cloud setups by ensuring application portability, reducing vendor lock-in, and optimizing resource usage across platforms. Its scalability and lightweight nature help in efficient scaling and resource management, minimizing costs. Docker's consistent development and deployment processes streamline workflows and foster seamless communication between services. Orchestration tools like Docker Swarm or Kubernetes further increase the management and scaling capabilities in multi-cloud environments. Docker's disaster recovery features and high availability options ensure reliability and continuity across diverse cloud providers, making it a versatile choice for multi-cloud deployments.

8. Configuration and consistent delivery of your applications

Docker helps set up and deliver apps in a consistent way. It keeps all the necessary parts of an app together in containers. These containers act like little packages that can run the app the same way every time across different stages. Container isolation prevents conflicts, maintaining application integrity and consistency in behaviour. Docker also makes sure we're using the right versions of everything, and it can quickly fix things if something goes wrong. This makes deploying apps easier and more reliable, especially when we need to update or scale them.

9. Pipelines

Docker improves pipelines by ensuring consistent environments across stages, reducing errors due to environment differences. Containers isolate the dependencies, avoiding conflicts and simplifying dependency management. Versioned Docker images enhance reproducibility and sharing within teams. Scalability is enhanced as containers can scale based on workload. Docker's lightweight nature and fast start-up times improve pipeline efficiency, speeding up builds, tests, and deployments. Portability across platforms allows pipelines to be moved easily. Overall, Docker enhances reliability, efficiency, and flexibility in pipelines, resulting in smoother software delivery processes.

10. Security

Docker boosts security by isolating applications in containers, limiting the impact of breaches. Containers include only essential components, which reduces vulnerabilities. Images can be signed for authenticity, preventing tampering. Once built, containers remain unchanged, enhancing integrity. Resource limits prevent attacks like resource exhaustion. Security policies enforce controls like network segmentation. Vulnerability scanning tools identify and mitigate risks during development. Logging and monitoring track container activity for suspicious behaviour detection. Overall, Docker's measures, from isolation to monitoring, fortify system security, making it a reliable choice for secure application deployment.

Difference Between Virtual Machine and Containerization

A virtual machine (VM) is a piece of software that allows you to install other software inside of it and operate it virtually rather than installing it directly on the computer. When we need all of the OS resources to run several programs, virtual machines (VMs) come in handy as it supports different OS and is more secure.

On the other hand, a container is a piece of software that allows separate aspects of an application to operate independently. Containers are important when we need to maximize the performance of running applications while employing the fewest servers possible. It requires far less memory and is far less secure. 

Check out the difference between Docker vs Virtual Machines. 

Tools and Terms of Docker

When utilizing Docker, you'll come across the following terminology: 

1. Docker Hub

A community resource for working with Docker that is hosted in the cloud. Docker Hub is mostly used for hosting images, but it is also used for user authentication and image-building automation. Anyone can upload images to Docker Hub for free. Individuals or organizations who contribute images to Docker Hub are not checked or verified in any way. 

2. Docker Store

Docker Store is a cloud-based repository comparable to Docker Hub, except that the images on Docker Store have been contributed by commercial businesses that Docker has approved or certified. 

3. Docker File

A text file with the commands for creating a Docker image. The commands you can specify in a Dockerfile range from sophisticated (such as specifying an existing image to use as a base) to basic (such as specifying an existing image to use as a base) (such as copying files from one directory to another).

For example, you could make a Dockerfile that starts with the Ubuntu image and then adds the Apache web server, your application, and any other configuration parameters you need. The docker build command is used to create an image from a Dockerfile. 

4. Docker Image 

A self-contained, executable package that can be used in a container. A Docker image is a binary that contains all of the necessary components for executing a single Docker container and metadata specifying the container's requirements and capabilities.

An image contains everything needed to run an application, including the executable code, any software that the application relies on, and any necessary configuration settings. You can either create your images (using a Dockerfile) or use images created by others and made available in a registry (such as Docker Hub).

The docker build command is used to create an image from a Dockerfile. The docker run command is used to run an image in a container. 

5. Sandbox

The term 'sandbox' refers to a computing environment in which everything that happens inside it stays inside the sandbox. If you run 'rm –rf' inside the sandbox, the contents of the sandbox will be deleted, but the host system that has the sandbox will be unaffected. 

6. Docker images are a type of container

Docker images consist of executable application source code and the tools required, libraries, and dependencies required for the application code to execute in a container. When you run the Docker image, it creates a single (or multiple) container instances from the code.

Although it is possible to create a Docker image from scratch, most developers use popular repositories. A single base image can be used to create several Docker images, and all of the created images will share the same stack. 

Layers constitute Docker images, and each layer represents a different version of the given image. A new top layer is created whenever a developer makes certain modifications to the image required, and this top layer replaces the previous top layer as the current version of the image. Previous layers are kept in a rollback manner or re-used in future projects. 

A new container layer is created whenever a container is formed from a Docker image. Changes to the container, which means adding or removing files, are only saved to the container layer and are only visible while the container is running. This iterative image-creation process improves overall efficiency because numerous live container instances can run from a single base image and share a stack. 

7. The Docker daemon is an identical program that runs in the background 

The Docker daemon is a service that runs on your operating systems, such as Windows, macOS, or iOS. This particular service, which acts as the control center of the Docker implementation, produces and manages your Docker images for you using commands from the individual client.

8. Docker Register is a registry for Docker containers

A Docker registry is a scalable open-source Docker image storage and distribution mechanism. The registry allows users to keep track of image versions in repositories by tagging them. Git, a version control tool, is also used to do this. 

Why Docker Matters?

The Docker project promotes itself as "Docker for everyone". And the reason for this is the ease with which it can be used. Even a non-technical person can easily start and execute any Docker project with just a few commands because this technology is so simple to master and completely Open Source.

Assume that a team of four developers is working on a single project. In the meantime, one uses Windows, and the other uses Linux, and the third and fourth use macOS. As you can see, they are utilizing separate environments to create a single program or software, and they will be required to do things according to their machines, such as installing different libraries and files for their system and so on.

And in such circumstances, particularly on a higher or organizational level, frequently result in multiple conflicts and challenges throughout the software development life cycle. Containerization solutions like Docker, on the other hand, eliminate this issue. 

Why Use Docker Compose?

Here's a detailed answer on Why use docker compose?
Docker Compose is a useful service that allows users to run several containers as one. All individual containers here run in isolation mode, but they can communicate with one another if needed. The scripting language YAML, which implies Yet Another Markup Language and is based on XML, makes writing Docker Compose files more comfortable. Another excellent feature of Docker Compose is that users may use a single command to enable all services (containers). 

You'll need to use a container orchestration tool to monitor and manage container lifecycles in more sophisticated setups. Although Docker has its identical orchestration tool (Docker Swarm), most developers prefer Kubernetes.

Docker Compose Advantages

• The term "single-host deployment" refers to the ability to execute everything on a single piece of hardware. 
• YAML scripts provide for quick and easy configuration. 
• Docker Compose increases productivity by reducing the time it takes to complete activities. 
• Security - Because all containers are isolated from one another, the threat landscape is reduced. 

Kubernetes

Kubernetes is an open-source container orchestration software tool that has evolved from a Google internal project. Kubernetes manages container-based systems by scheduling and automating processes like container deployment, updates, service discovery, storage provisioning, load balancing, health monitoring, and more. Furthermore, the open-source Kubernetes ecosystem consists of technologies, such as Istio and Knative, which enables enterprises to install a high-productivity Platform-as-a-Service (PaaS) for containerized applications and a speedier on-ramp to serverless computing systems. Learn Docker and Kubernetes with knowledgeHut. 

Conclusion

Docker is a fantastic tool that aids in the continuous deployment process. It's well-integrated with existing configuration management software. Its large and developing ecosystem has a wide range of applications. Why use Docker? Docker offers numerous benefits, and can help you construct containerized apps and multi-container apps. There are numerous Docker certification courses available in the market, and one can choose them based on individual requirements. You can visit the DevOps course for outcome-based learning of the most needed software tools.