Today, every app development business is using a container technology like Docker to boost their productivity. This, however, wasn’t the case always. Let’s start this blog post by discussing briefly the advent of containers.
A Brief History of Containers
The containerization approach is not new but gained momentum in the 2000s, with the introduction of FreeBSD jails. It allowed making multiple partitions on the same system. Container technology, however, gained more popularity after it was recognized by the CNCF.
Earlier, all the containers were Linux-based, but in 2016 Microsoft became a significant influence after running containers on Windows. In 2017, the introduction of Kubernetes (a container orchestration technology) and container tools like Docker, introduced in 2013, further improved the landscape for the containerization technology.
In 2021, container technology is at its peak and is being adopted by many companies to make their development and deployment process efficient and faster. Significant cloud computing platforms have also embraced containerization technology.
Introduction to Containers
Containers were introduced to solve the problem of running a particular software on various platforms and to transfer software from one platform to another easily.
The major problem occurs when the SSL libraries may vary, different network topology or security policies are not the same on supporting software environments (testing and production), and may disrupt the working of the project.
The container technology ends all these problems. A container allows you to bundle the complete application along with its dependencies and required files into an isolated package. You can easily avoid the differences in OS/distributions by containerizing applications.
Running an application inside a container(s) will isolate it from other processes. The container ensures decoupling of applications so they can be deployed efficiently and consistently on any platform without relying upon the target environment.
Containerization benefits not only the app organization but also the team productivity. It allows the developers to focus on the code logic and the IT team to focus on deploying and managing applications without each of them getting into the system details.
You can consider a container as the virtualization of an operating system. With the help of a container, you can run either small applications, microservices, or complex applications.
Features of Containers
Containers streamline the build, test, and deployment process of applications on various platforms, ranging from on-premises to hybrid. Below are some important features of containers:
- Compared to the traditional virtual machines, containers require fewer system resources as they do not work on the OS images to run applications.
- Containers help enhance the application portability as it allows the applications to run on multiple operating systems and hardware specifications consistently providing the same desired output.
- With containerized applications, you do not have to worry about how your application will run in the target environment.
- Using containers enhances the efficiency of deploying, patching, and scaling applications.
- The containerization technology provides a better application development on integration with the DevOps process and speeds up the development, test, and production cycles.
Use Cases of a Container
Below are the areas/purposes where the container technology works the best:
- Transfer the existing applications to more advanced cloud architecture.
- Refactor the containerized applications, which is a more intense process than migrating the application.
- Quickly isolate, deploy, and scale the distributed applications and microservices.
- Streamline the build, test, and deploy process on various platforms using the same container image.
- Run one or more background processes, like batch jobs and ETL using containers.
- Run multi-tenant applications without rewriting the time-consuming and costly applications. It helps in developing a multi-tenancy IoT application to run multiple instances of application tiers per tenant.
- With containers, you can achieve server consolidation ROI to reduce the data center requirement, reduce cost, and maximize the server capacity. You can run multiple containers on a single server sharing the unused memory across instances.
- The containers use microservices to develop complex applications that can interact with each other to create new services or applications.
Benefits of Using Containers
Below are some benefits of implementing the container technology:
- A container is a lightweight entity that helps in creating a fast and isolated infrastructure to deploy and run your applications. Due to its lightweight nature, you can create backup and restore data faster and efficiently.
- As containers are popular for packing up the services or applications along with files and dependencies required to run the same, it makes them a better portable option. It can be transferred to another platform if business requirements change.
- The container size is significantly less compared to virtual machines, making containers fast to deploy. Moreover, containers consume fewer resources.
- Choosing a container is a cost-effective approach that helps in reducing operating and development costs.
- You can efficiently run multiple containers on a single host, which is not the case with a virtual machine. Doing so helps in optimizing resource usage.
- You can install the container application on any server running any operating system, and you do not have to create or customize the configuration of the development environment.
- When you integrate the container technology with the DevOps process, it enhances the flexibility to run containers on various platforms and ensures automation throughout the DevOps pipeline.
Challenges in Using Containers
There is no doubt that containers are very useful. They, however, have their own issues. Some of the most important ones are discussed below:
- Due to the origin of the Linux Containers environment, containerization is generally limited to the Linux operating system. You can use Windows for containers, but it is not that much supported as Linux.
- As containers share the underlying operating system’s kernel, all the running containers will also be compromised if there is any failure at the kernel level.
- You have to make sure the network connection is strong enough to keep your running containers isolated. It can be a tricky situation while maintaining a network with containers.
- As you keep your applications isolated in different containers, it becomes more difficult to handle multiple containers than working on the complete project on your virtual machine.
- Continuous container monitoring is difficult.
- Sharing container templates to a growing ecosystem can be an entry point for hackers and increases security challenges. So you have to screen every shared container before using it.
How is a Container Different from a Virtual Machine?
Before containers, we relied on virtual machines for running multiple applications on one physical server. Each virtual machine has its entire operating system along with applications to run on them. You can run many virtual machines on a single physical server with a single hypervisor emulation layer on the top.
Running several servers can cause overhead due to resource consumption. But with container technology, you can run a single operating system on the server, shared by many containers running on that server.
These containers share the same OS kernel without interfering with other running containers. Unlike virtual machines, containers use fewer resources resulting in less overhead. Thus, it is very efficient to run multiple containers on a single server.
What is a Docker Container?
Docker came into the picture in 2013. The containerization technology mostly focuses on the requirements of developers and system operators that keep the infrastructure isolated from the application dependencies.
After this concept got success with Linux, it started working with Microsoft that led to the emergence of Docker containers for Windows Server. Docker helps developers create, test, and deploy containerized applications on various platforms. It has changed the operational perspective of the software industry.
Docker containers are light-weight, standalone, executable packages of software bundled up with runtime, code, system tools, libraries, and settings. It is available for both Windows and Linux-based applications. These containerized applications will run the same on every platform irrespective of the underlying infrastructure.
Conclusion
Containers are now widely used by enterprises irrespective of their business size. With many benefits, they have changed the perspective of developing and deploying applications. Containers enhance portability, performance, productivity, and team collaboration.
Once you get the basics and purpose of containers, it will be easier to implement the same within your enterprise. It doubles the benefits when integrated with the DevOps pipeline.