Kubernetes Deployment Vs Service: What's The Difference?

By Author: Taras Tychkivskyi
Total Articles: 2
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The number of companies that keep launching major digital transformation projects in 2022 is only growing, and it’s easy to see why, since these initiatives enhance IT and business capabilities while saving costs at the same time.

As part of their digital transformation, organizations focus on modernizing legacy systems, streamlining infrastructure, and launching apps faster. This has led to increased use of сontainerization, which breaks down applications into more digestible and smaller modules.

Containers enable companies to deploy their applications more efficiently, speeding up time to market because of the enhanced and more consistent release cycles. But running containers at scale requires orchestration and management of distributed, containerized applications via an orchestration platform such as Kubernetes.

Actually, 96% of organizations reported using or evaluating Kubernetes as their orchestration platform of choice. Find out what exactly Kubernetes does, Kubernetes deployment vs service, and how you can benefit from this technology.

What is Kubernetes?
According to the official ...
... page:

Kubernetes is an open-source system for automating deployment, scaling, and management of containerized applications. It groups containers that make up an application into logical units for easy management and discovery.
Kubernetes is a nonprofit project that Cloud Native Compute Foundation (CNCF) accepted on March 16, 2016. The Foundation’s goal is to make cloud-native computing ubiquitous. The CNCF states:

With cloud-native technologies, businesses are empowered to build and run highly scalable applications in dynamic environments such as public, private, and hybrid clouds. Containers, service meshes, microservices, immutable infrastructure, and declarative APIs best resemble this innovative approach.
Such techniques enable scalable and manageable loosely coupled systems that together with robust automation allow engineers to bring about high-impact changes frequently and predictably with minimal effort.
The Cloud Native Computing Foundation aims to make these innovations accessible for everyone and drive the adoption of this approach by fostering and maintaining an ecosystem of open-source, vendor-neutral projects.
Kubernetes can manage many server computers and run multiple programs across those computers. The tool builds upon 15 years of experience of running production workloads at Google, combines the best industry practices and has the following advantages:

It can scale without increasing your ops team as it is built on the same principles as Google, running billions of containers a week.
Kubernetes removes many manual processes connected with the deployment and scaling of containerized applications.
The technology is open source, which means you can take advantage of on-premises, hybrid, or public cloud infrastructure, and easily move workloads to where you need.
It is a highly flexible solution that grows with you to deliver your applications regularly and easily no matter how complex your requirements are.
What can you do with Kubernetes, its services and deployments?
Organizations that focus on innovating their operations and tools rapidly need to be able to upgrade and redeploy their apps with ease. Enabling developers to speed up the process of building apps and adding new features is key to digital transformation of their business. That’s where Kubernetes comes into play.

Kubernetes allows you to deliver and manage containerized, legacy, and cloud-native apps, along with those being reengineered from monolithic to microservices. Also, it handles scaling and failover of your applications, runs distributed systems resiliently.

The use of Kubernetes enables:

Orchestration of containers across a number of hosts. Orchestration is essential to speeding up container usage and allows for portability between OS platforms and between clouds.
Load balancing and distributing the network traffic to ensure a stable deployment even when traffic to a container is high.
Managing and automating application deployments as well as updates dynamically as applications are broken into smaller, independent pieces.
Automated rollouts and rollbacks to change the actual state of your deployed containers, create new or remove existing ones.
Self-healing. Monitor the health of your apps and let them self-heal with auto replacement, auto restart, and auto replication.
According to VMware study, organizations that have been using Kubernetes services and deployments realized such benefits as improved resource utilization, eased application upgrades and maintenance, shortened software development cycles, enabled cloud migration, and reduced public cloud costs among others.

Kubernetes service vs deployments: what is the difference?
What is a Kubernetes deployment?
Within Kubernetes, organizations can alter the state of pods, which may include one or more containers that are running, or a set of duplicate pods, called ReplicaSets. Pods by themselves are not self-healing and therefore are fragile. They can easily go down if some interruptions on the server occur and can negatively affect your entire application. Kubernetes deployments can prevent this downtime from happening.

Deployments allow you to describe the desired state for your application and Kubernetes will make sure the requirements you set are matched by all pods. If some pod goes down because of an interruption, ReplicaSets controller will spot the error and a new pod will be created that matches your requirements.

How do Kubernetes deployments work?

It is with Kubernetes deployments that you can scale the amount of replica pods, roll out refined code in a supervised way, or roll back to an earlier deployment version if there is such a need.

There are different K8S deployment strategies that help you minimize downtime while performing application upgrades:

Recreate - destroying all pods and then creating them again.
Rolling (or Ramped slow rollout) - gradually shutting down old replicas while introducing replicas of the new app version, one after the other.
Blue/green deployment - running two versions of the app (old and new) in parallel, then shifting all traffic to the new version.
Canary deployment — rolling out software updates to a small part of the users first for testing and keeping the old version for other users. If successful, rolling out an updated version for the rest of the users.
What is a Kubernetes service?
Deployments in Kubernetes make sure your application is up and running by keeping the desired number of pods active and replacing unhealthy pods with new ones.

As a pod is assigned an IP address which allows an access from within the cluster, it can easily communicate with other pods in a cluster that hit that IP address. However, when the old pod gets replaced with a new one, it will have a different IP address. Other pods need to know this new address for communication to continue.

While there are ways to circumvent this issue without using services, they are really elaborate and may cause more problems as the number of pods grows. The more pods are running your application, the more IP addresses are changing. It will become really challenging eventually to keep stable communication between the outside world and your app, as well as between numerous apps inside your cluster.

A Kubernetes service can solve this problem.

Unlike deployments, a service makes a set of pods available to a cluster network or directly to the internet, by providing a static record in front of it. So, instead of making a connection with the pods directly, you would talk to the service, which then transfers the traffic to the pods.

There are a few options for how a service can be exposed:

ClusterIP: Exposes the Service on a cluster-internal IP. This value enables Kubernetes Service to be reached only from within the cluster. This ServiceType is the default.
NodePort: The Service is exposed on each Node's IP at a static port (the NodePort). It leads to an automatic creation of a ClusterIP service, to which the NodePort Service routes. The request : will allow you to contact the NodePort Service from outside the cluster.
LoadBalancer: With a cloud provider's load balancer the Service is exposed externally. There is an automatic creation of NodePort and ClusterIP Services, to which the external load balancer routes.
ExternalName: Maps the Service to the contents of the externalName field (e.g. foo.bar.example.com) by returning a CNAME record with its value. There is no proxying set up.
You can expose your Service also with the help of Ingress. Though Ingress is not a Service type, it acts as the entry point for your cluster. With it, you can consolidate your routing routes into a single resource because it has the ability to expose multiple services under the same IP address.

How do Kubernetes Services work?

Kubernetes services select pods based on their labels. So, when a service receives a network request, it selects all pods in the cluster that matches the service’s selector, chooses one of them, and forwards the network request to it.

So, what are the key distinctions between Kubernetes services vs deployments?
1. Kubernetes service enables network access to a set of Pods.

2. Kubernetes deployment is in charge of keeping a set of pods running.

Kubernetes services vs deployments can’t be compared as they perform different functions, but they complement each other nicely. By using Kubernetes deployments, you keep your application in the desired state, and by using services you ensure a steady and adjustable communication between almost any kind of resource and the cluster of your application.

Enhance your DevOps with Kubernetes services & deployments
Modern applications require different development processes compared to the approaches of the past. DevOps services enhance the application’s lifecycle, speeding up how it moves from development to deployment. In its foundation, DevOps is centered around automating routine operational tasks and regulating environments across an application’s lifecycle.

Сontainers are designed to support these goals, as executable units of software in which application code is packaged, along with its libraries and dependencies. In this way, these units can be easily deployed, updated, and scaled up or down as needed, which will also accelerate the app’s transition between development, testing, and production environments.

By using Kubernetes alongside DevOps to manage the lifecycle of containers, businesses can align their software development and IT processes to support a continuous integration/continuous delivery pipeline. This tandem can help you deliver apps to customers more frequently, shorten software development cycles, and validate software quality with minimum human involvement.

Need help adopting the right platforms and implementing the culture and process changes with experienced DevOps assistance? Feel free to ask us any questions you may have even now.

Marketing Manager at https://apiko.com/