Containers in the digital world are not related to shipping boxes. Basically, they are lightweight, standalone units that package up software code with everything it requires to run: the system tools, libraries, and settings. Consider them as a portable environment, ensuring your application works in the same manner no matter which system is deployed on it.
Now, let’s get a deeper insight on what are containers? Well, they resolve several web development issues that developers and the IT teams face. Whether it is easier scalability or faster deployments, containers make application development and management easier. In this blog, we delve deeper into the insights of what containers are and their significance.
Table Of Content
What Are Containers?
Containers can be defined as an efficient way of developing and deploying applications. Containers provide an organized packaging system though which the applications can be extracted from the environment in which they are operating. This decoupling method enables the applications based in the containers to be deployed consistently and easily irrespective of whether the target environment is a public cloud, a private data center or the personal laptop of a developer. A cloud hosting platform enables containerization of the applications, it is possible to attain a clean separation of all the aspects. This enables the developers to concentrate on application logic and dependencies and the IT operation teams can concentrate on the deployment and management aspects without worrying over application specifications like particular software versions and configurations specific to the application etc.
For those utilizing the virtualized environments, containers are usually compared with virtual machines (VM). A VM is a guest operating system like Windows or Linux that operates on top of a host operating system with a virtual access to the underlying hardware. Similar to the virtual machines, with the use of containers developers can club the application together along with the libraries and dependencies. The similarities finish as the containers offer a lightweight unit for the developers and the IT Ops teams to work with thus ensuring many benefits.
The Google Way Of Using Containers
Google operates everything in containers right from Gmail to YouTube to Google Search. Containerization enables the development teams work, deploy the software more efficiently and function at an unpredictable scale. Every week Google starts over 2 million containers. Google has a great experience in terms of running containerized workloads and they have shared all the knowledge and information with the community.
How Container Works?
At the core of container technology, there is an idea of packaging your app requirements, code, runtime, libraries, and system tools into a single unit known as the container image. It acts as a blueprint that is used to create running instances called containers.
Once the container image is ready, it is executed by the orchestration platforms like Docker or Podman. Every container runs in its isolated environment, which means it does not interrupt any other application or the host system.
Types of Containers
Now, we will be discussing different types of containers used in the technological world.
1. Application Containers
Tools like Docker come under the application containers category. Its main objective is to package a single application or a service. It results in a web server, a database instance, or a microservice. All packages include all its runtime dependencies, libraries, and configuration. Everything is bundled into a lightweight, isolated unit.
2. System Containers
System containers, often instantiated with LXC (Linux Containers), aim to operate akin to a more lightweight virtual machine. Differently from application containers, which are centered around a single process, a system container functions as an environment within which a complete operating system can be hosted. It has an init system (like systemd) that can start and supervise multiple processes within the container.
3. Stateless Containers
Stateless containers pertain to a particular operational attribute of a container wherein no data of any kind is retained within the unit’s filesystem. Any data stored locally will be erased if a stateless container is stopped or redeployed. This design philosophy guarantees that the container can be seamlessly substituted, scaled, or relocated between hosts without the need to evaluate for data loss or state desynchronization within the container.
Why Containers?
The approach of virtual machines is to virtualize the hardware stack and on the other hand, containers virtualize at the operating system level with multiple containers operating directly on the OS kernel. This implies that containers are more lightweight: they share the OS kernel; they start faster and utilize only a fraction of memory as compared to booting of a complete OS.
Containers are available in many formats. Among all the formats, the Docker container is a commonly used. Docker is an open-source container that is also supported on the Google Cloud platform and by the Google Kubernetes engine.
– Consistent And Reliable Environment
Through containers, developers get the ability to create predictable and isolated environments for their applications. Containers can also incorporate the software dependencies required for the application like some particular versions of the programming language runtimes and software libraries. If we look at it from a developer’s viewpoint, all these aspects are guaranteed to be consistent irrespective of whether the application is deployed on time or if it is untimely deployed. higher productivity is ensured as the developers and IT Ops teams will have to spend less time in debugging and analyzing the differences in environments and they can concentrate more on ensuring new functionalities for the users. This results in a fewer bugs as the developers get the ability of making assumptions for the dev and test environments and they can be sure that the assumptions will hold true in production.
– Operate Anywhere
One of the best things about containers is that they can be operated virtually anywhere and this simplifies the process of development and deployment to a great extent on Linux, Windows and Mac operating systems, on the virtual machines, on bare metal server, on the developer’s machine or in the data center premises and in the public cloud as well. The Docker image format is an extensively popular format for the containers that further helps with portability. you can use containers and run your software wherever you want.
– Isolation
Factors like CPU, storage, memory and network resources are all virtualized in the containers at the OS-level. This helps in providing the developers to get a better insight about the OS that is perfectly isolated from the other applications.
| Container Benefits | Virtual Machine Benefits | |
| Consistent Routine Environments | ✅ | ✅ |
| Application Sandboxing | ✅ | ✅ |
| Small Size On Disk | ✅ | ❌ |
| Low Overhead | ✅ | ❌ |
– From Code To Applications
With containers you can package your application along with its dependencies into a compact format that can be controlled through version; thereby, enabling easy replication of your application with all the developers of your team and with all the machines in your cluster.
Just like the way in which the software libraries package parts of code together that enables the developers to abstract logic on aspects like user authentication and session management; containers enable your application to be packaged completely by abstracting the operating system, the machine and the code. As the containers are based on a service-based architecture, the complete unit the developers are supposed to work on reduces in size thus resulting in higher agility and productivity. All this helps in easing the aspects like testing, development, deployment and the overall management of your applications.
– Monolithic To Service Based Architecture
Containers work best when it comes to service based architectures contrary to the monolithic architectures where every part of the application is interconnected right from IO to data processing to rendering; the service based architecture separates these aspects into individual components. The separation and division of labor enables the services to go on consistently even if the others are failing this making sure that your application is more reliable.
With the help of componentization you can develop applications faster and with more reliability. It is easy to deal with smaller codebases and because the services are separated, testing some specific inputs and outputs also becomes easier.
Containers are ideal for the service based applications as it is possible to health check every container, limit each service to particular resources and stop the services independently from each other.
Containers extract the code right away, this enables the users to deal with separate services like black boxes; this further reduces the space required by the developers. When the developers need to work on services that depend on other, they can easily start a container for a specific service without putting a lot of time in setting up the environment and without doing any troubleshooting in advance.
