There is no argument that sustainable agility is a critical element in today’s digitally powered business world. It is not a secret that every software development company is aspiring to increase the rate of software development, deployment, and responsiveness to evolving customer demands. On top of these requirements, containers, containerization, and container deployments have bloomed with the maturity of virtualization and cloud computing. Likewise, you may also have wanted to power up the DevOps sector of your organization to embrace automated deployments.
Undoubtedly, Kubernetes: as an open-source system for automating deployments, maybe one of the first options you chose for this upgrade. But, Kubernetes: still being an emerging technology, has a void for knowledge to implement this technology in the right way. There are many basic aspects that you need to consider to implement Kubernetes the right way. That is why I bring this article on Kubernetes deployments with the right ways to help your business accelerate in continuous development, integration, and deployment while achieving maximum resource utilization and agility.
Container Deployments Vs. Kubernetes Deployments
Before the dawn of the container deployment era that you and I are now passing, virtualized deployment was the popular mechanism for application deployment to provide a level of security for applications and to allow better utilization of resources in a physical server. In a way, container deployments are an extension of virtualized deployment technology. Because containers also have similar isolation properties as of VMs. But, ahead of VMs, containers can share a single operating system (OS) among the applications and are completely decoupled from the underlying infrastructure.
How does Kubernetes stand out from other container deployment or container cluster management software?
When containers became a smart approach to bundle and run applications, the need for a resilient or a fault-tolerant system of containers was strongly felt. Therefore, the Kubernetes container orchestration system was designed by Google to take care of scaling and failover management of application containers, create and schedule deployment patterns to automate deployment.
Compared to many other container orchestration software available in the market, Kubernetes provides an exceptional developer user experience, and their rate of innovation is phenomenal. Also, with Kubernetes, your organization can have your Heroku running in your own Google Cloud, AWS, or the on-premises environment as you desire. The below-listed features make Kubernetes an ideal CI/ CD tool over many container deployment software.
Kubernetes: the right way to Continuous Deployment
I have suggested some best practices from research and experience to maximize Kubernetes features for effective application deployment on its platform.
1. Kubernetes’ Pods the right way
Kubernetes use pods as the basic building block for deployment. One or more containers grouped to use the same network and storage with the specification for how to run the grouped containers is known as a pod.
Be smart. Go for the right image.
Think, for example, the app you need is only 20 MB in size, but you select an image with a 500 MB library to feel safe with some excess. But the truth is that the smaller your image, the faster your container will build. This would often reduce the attack surface enhancing your overall security. Also for instances such as log monitoring, try to apply multiple Pods to tightly couple helper processes to your primary lead Pod. Moreover, running multiple containers in Pods when using a Service Mesh for microservices will benefit for communication between the individual microservice components.
Double verify the base image.
Use programs like CoreOS’ Clair or Banyon Collector if they aren’t already installed to your platform to run a static analysis on your container. This would help to detect any vulnerabilities embedded in your base image.
Use Namespace and labels
Log in as a non-root user to each container because it will prevent any intruder by a chance of getting access and control to desolate the system. The use of Namespace and labels in Kubernetes clusters is a best practice to ensure long-term and hassle-free maintainability.
2. Kubernetes’ Services the right way
A Kubernetes service is an abstraction to define a logical set of Pods and a policy to access them. Services enable a loose coupling between the dependent Pods. They enable load balancing across a set of server pods, allowing client pods to operate independently and durably.
To use Kubernetes Services the right way, get started with your Services before starting your Pods. So it will make you identify the services which were running before your containers run. To ensure timely and efficient tapping to your services, use the DNS name of the service when writing code to talk to it.
3. Kubernetes’ Configuration the right way
Kubernetes operates on a declarative model. Therefore, having more readability to YAML files, it is best to use YAML rather than JSON to write your configuration files. ConfigMap is the concept in Kubernetes to configure files for your application and to define environment variables. Secrets: similar to the operation of ConfigMaps, but less visible to the end-users helps define how you run your application. With ConfigMaps and Secrets, Kubernetes allows us to know what is happening with interconnected systems across servers.
4. Kubectl: Deployment History the right way
The kubectl rollout history is a feature in-built to the Kubernetes platform to check on deployment status. This feature offers an unlimited and permanent system audit log where you no longer have to use manual and scripted releases. Recommended below are two simple tips to efficiently use Kubectl.
- Use ‘Kubectl expose’ and ‘kubectl create deployment’ to create single-container Deployments and Services, quicker.
- Use a directory of config files as much as possible to call Kubectl commands.
5. Liveness probe and readiness probe the right way
The capability of Kubernetes to perform automatic health checks is a mind relieving feature for any DevOps engineer. In the past, whenever an application crashed, someone got paged in the middle of the night and had to restart again. Kubernetes uses the liveness probe and the readiness probe to check whether the application is up and running. Readiness probes decide when the container is available for accepting traffic. If you have properly configured the readiness probe, you will very rarely get a rollback. You can use the below tips to configure the readiness probe the right way.
- Set the readiness probe timeout longer than the maximum response time for a container evaluating a shared dependency like a common service used for authentication, authorization, metrics, or metadata in the readiness probe.
- Increase the ‘FailureThreshold’ count of the readiness probe depending on its frequency to avoid failing the readiness probe prematurely before temporary system-dynamics have elapsed.
Liveness probe checks if the application transitions to an unhealthy state and in such cases restarting the application. However, to reap the best out of this feature exercise the below tips.
- Don’t check dependencies on liveness probes.
- Set liveness probe timeout conservatively not to experience liveness probe failures.
With the above features, Kubernetes has solved the fussy issue of completely rolling back updates that DevOps engineers have been facing for decades.
Other than the above mentioned best practices, always keep in mind to update Kubernetes to its latest version and to use a monitoring tool having Kubernetes integrations providing advanced monitoring and alerting capabilities. Every new release of Kubernetes bundles up with a host of different security features. Use Kubernetes the right way and reap the best out of this awesome technology.
Final Thoughts for Kubernetes Deployments the Right Way
This article only touches upon the basic features of Kubernetes and their respective best practices which make Kubernetes stand out among other same age container deployment tools. Many other minor configurations can be implemented to best automate and fine-tune for Kubernetes Deployments the Right Way.