Kubernetes, often abbreviated to (K8s), is an open-source container orchestration platform that automates the deployment, scaling, and management of containerised applications. Containers are lightweight, portable, and consistent environments that package applications and their dependencies, ensuring that they can run consistently across different computing environments.
Prior to Kubernetes and Containerisation
Before the widespread adoption of containerisation, web applications were typically deployed using different methods and technologies that didn't involve containers. Here are some common deployment approaches used prior to the containerisation era:
1. Traditional Bare-Metal Servers:
- In the early days of web applications, they were often deployed on physical servers or virtual machines (VMs). Administrators would manually configure these servers, install the necessary dependencies, and deploy the application code directly onto the server.
2. Manual Configuration:
- System administrators would manually configure servers by installing the required software, libraries, and dependencies. This process was often time-consuming and error-prone, and it made it challenging to replicate the same environment across different servers or environments.
3. Application Servers:
- Web applications were often deployed on dedicated application servers such as Apache HTTP Server, Nginx, or Microsoft Internet Information Services (IIS). These servers handled incoming requests, managed the application runtime, and served static content.
4. Manual Scaling:
- Scaling web applications to handle increased traffic often involved manual efforts to add more servers to the infrastructure. This process required predicting traffic patterns and adjusting server capacity accordingly.
While these methods served the needs of the time, they lacked the portability, consistency, and efficiency that containerisation brings to modern application deployment. The advent of containerisation, led by technologies like Docker, brought about a shift in how applications are packaged, deployed, and managed, offering benefits such as isolation, reproducibility, and simplified deployment across diverse environments.
Strengths of Kubernetes
Kubernetes originated from Google's internal container orchestration system called Borg, which had been used to manage their large-scale containerised applications for many years. Google decided to open-source Kubernetes, in July 2015, to provide a standardised and community-driven platform for container orchestration, aiming to simplify the deployment and management of applications in containers, foster collaboration in the industry, and address the emerging needs of containerised application development and deployment.
Here are some key reasons why Kubernetes is widely used:
1. Container Orchestration:
Automated Deployment: Kubernetes simplifies the deployment of containerised applications, allowing developers to describe the desired state of their applications through YAML or JSON files.
Scaling: It enables easy scaling of applications by adding or removing instances of containers based on demand.
2. Portability and Consistency:
Cross-Cloud Compatibility: Kubernetes provides a consistent environment across various cloud providers and on-premises infrastructure, allowing applications to run unchanged in different environments.
Isolation: Containers encapsulate applications and their dependencies, ensuring consistency and isolation. This makes it easier to move applications between development, testing, and production environments.
3. Automated Operations:
Self-healing: Kubernetes monitors the health of applications and automatically restarts or replaces failed containers, ensuring high availability.
Rolling Updates: It supports rolling updates, allowing applications to be updated without downtime by gradually replacing old containers with new ones.
4. Declarative Configuration:
Infrastructure as Code: Kubernetes configurations are written as code, which means that the desired state of the application is declared, and Kubernetes works to bring the system to that state.
Version Management: Declarative configurations means it's able to easily version specific deployments further enhancing traceability and debugging power.
5. Service Discovery and Load Balancing:
DNS-Based Service Discovery: Kubernetes automatically assigns DNS names to containers, making it easy for one container to discover and communicate with another.
Load Balancing: It provides built-in load balancing for distributing network traffic to containers.
Role-Based Access Control (RBAC): Kubernetes has robust RBAC features, allowing administrators to control access to resources.
Secrets Management: It provides a way to manage sensitive information, such as API keys and passwords, securely.
Kubernetes at WorkingMouse
We use Kubernetes at WorkingMouse on a day-to-day basis. From our cloud deployed client applications to our internally deployed review sites that are spun up per Merge Request. It proves to be an extremely valuable resource for all our developers here at WM, from DevOps to Software. Our DevOps developers praise Kubernetes due to all the reasons listed in the previous section, but mainly for points 3 and 4. Automated Operations significantly simplifies our deployment process meaning that a traditionally dangerous operation is simplified and made far more consistent. Declarative Configuration means with the combination of Git we are able to explicitly track what changes were made and when, allowing us to easily and efficiently identify when (preferably if) bugs were introduced. Kubernetes allows our Software developers to introduce more complex integrations/micro services that live along-side our deployed application, as they are able to create an additional deployment through an extremely small set of YAML configurations. This allows us to continuously push the boundaries of the applications we develop, and as a company that strives for continuous innovation, instilling this ability into our Software developers is vital.
In conclusion, Kubernetes stands as a transformative force in the realm of container orchestration, unlocking unprecedented capabilities for developers and operations teams alike. Its power lies not just in automating deployment and scaling but in fostering a paradigm shift towards a more efficient, scalable, and resilient infrastructure. Here at WM it has emerged as the cornerstone, providing a standardised platform that transcends the complexities of managing containerised applications. With its thriving ecosystem, robust community support, and adaptability across diverse environments, Kubernetes empowers teams to focus on innovation and agility, ushering in a new era of seamless, scalable, and portable application development. Embrace the power of Kubernetes, and embark on a journey where your applications can thrive in the dynamic landscape of modern computing.