NGINX Ingress Controller 101 - Load Balancing for Kubernetes
Learn how to use nginx ingress controllers: production-grade controllers that run alongside NGINX open source in a Kubernetes environment.
Kubernetes today is a game-changing platform that has revolutionized the industry’s approach to building highly-distributed software systems in the cloud. It has been the default form of running your containers for some time now and is the default container orchestrator for most organizations today.
At the core of Kubernetes lies its ability to optimize and leverage the containers you create, empowering you to make the most of your servers and utilize your resources strategically.
A Quick Glance At Containers
A container acts as a piece of technology that helps package the code you have put together for an application and the dependencies it requires while running. These containers are standardized, therefore facilitating a level of stability and certainty.
Containers have become a new and inexpensive way of storing your web server, database, messaging, and other artifacts in a dedicated space. They eliminate dependence on any guest OS by running as individual processes while depending on one single, dedicated OS. This allows your application to be self-contained and independent of other linked applications and dependencies.
While containers solve a number of problems, they also led to the rise of a new one: how do you expose HTTP and HTTPS from outside one of the clusters to those within the cluster?
That’s where Ingress comes into play.
What is Ingress?
Ingress is an API object that manages external access to services within the cluster and is one of Kubernetes’ most crucial resources. Ingress leverages pre-defined traffic rules to allow certain external users and applications HTTP and HTTP access to services within the cluster. These rules are defined by you and dictate the manner in which Ingress will act.
In the absence of Ingress, you would be forced to probably use a dedicated load balancer to expose each service individually. As you scale up your application and dive into numerous services, lacking Ingress will lead to you resorting to such tiring and expensive measures. With Ingress, the number of load balancers you require goes down to just one in most cases.
Figure: Ingress - Source
How Ingress Operates
Ingress essentially is made up of two components, with each part playing a highly specialized role. These are:
- Ingress Resource
- Ingress Controller
Ingress Resource consists of a set of rules and instructions created by you to manage inbound traffic movement toward access Services. The rules you establish allow hostnames, and paths you may desire, to move toward specific Services within Kubernetes.
Ingress Controller, on the other hand, works to enact the rules you have set, usually using an HTTP or L7 load balancer. It ensures that your inputs to the Ingress Resource are followed consistently.
Therefore, it becomes essential to properly configure both halves of Ingress for smooth routing of traffic from an external client to the Kubernetes Service of your choosing.
Figure: Ingress Controller
The NGINX Ingress Controller
In order to utilize Kubernetes Ingress, you need to finalize and deploy a specific Ingress Controller. NGINX Ingress stands as one of the most popular choices when it comes to an Ingress Controller, as it offers a range of features along with boasting inherent robustness.
At its core, the NGINX Ingress Controller is a carefully-designed production-grade Ingress controller. To function effectively with Kubernetes, it takes advantage of NGINX Open Source and NGINX Plus instances. This controller keeps an eye on NGINX Ingress and Kubernetes Ingress resources to identify any and all requests that necessitate load balancing, thus acting as a specialist load balancer.
With Kubernetes becoming the standard solution for managing containerized applications, moving your current production workload into Kubernetes can bring significant traffic management challenges and complexities. The NGINX Ingress Controller acts as a specialized solution to this issue, acting as a bridge between Kubernetes services and external offerings.
The NGINX Ingress Controller has become an immensely popular choice due to its ability to support a diverse range of offerings. To date, it supports:
- SSL Services
- Rewrites
- Websockets
And a whole lot more!
Spelling It Out: Understanding Key Terminology
Before we dive into the function of NGINX Ingress Controller and how exactly to use it, let us take a few moments to go through a few key terminologies.
- Node: A Node essentially acts as a worker within Kubernetes and is the individual component that forms the foundation of a cluster.
- Cluster: A Cluster is formed when a set of Nodes that are tasked with running containerized applications come together. A Cluster is managed by Kubernetes and is usually not a part of the public internet.
- Cluster network: A series of logical or physical links that works to provide communication abilities within clusters.
- Service: Finally, a Service is a set of clusters that have been brought together using label selectors. Most times, Services only contain virtual IPs that are only routable within the selected cluster network.
The Role Of NGINX Ingress Controller In Kubernetes
The NGINX Ingress Controller plays certain key roles for Kubernetes. Whenever any traffic from outside the Kubernetes platform arrives, the controller accepts the traffic and load balances it so it can reach the various containers within your platform.
The NGINX Ingress controller also manages the egress traffic present within a cluster for services that may all need to communicate with an external service. The controller also keeps a close eye on all the containers running in Kubernetes. This allows it to automatically revise the load-balancing rules whenever you add or remove containers from a particular service.
How Does The NGINX Ingress Controller Help?
NGINX Ingress Controller is particularly useful in certain situations, such as your company facing the constant need to apply configuration changes to your current Ingress controller. Similarly, if protecting your Kubernetes services is of significant importance to you, this controller can be your solution. The NGINX Ingress Controller is capable of dynamic reconfiguration along with an exceptional web application firewall that is also lightweight.
Why The NGINX Ingress Controller In Particular?
Well, NGINX offers certain benefits that make it superior to its competitors. For a while now, the NGINX Ingress Controller has emerged as the preferred controller for organizations, and these may be the reasons for their choice:
Unparalleled Security For Your Applications
As more and more businesses base their applications on Kubernetes, basic security is no longer enough to protect them. Web Application Firewalls, or WAFs, have become a necessity alongside applications so that various points of failure are targeted and removed.
NGINX has addressed this issue by completely integrating the NGINX Ingress Controller for NGINX Plus with NGINX App Protect in an accessible configuration that reduces the complexity of your applications as well as the cost involved.
A Robust Feature Set
The NGINX Ingress Controller has been designed specifically to work with containerized apps. It has a long list of container-specific features that make it ideal for the task.
It provides you with the option to use role-based access control (RBAC) to ensure that your team manages their respective apps in a secure manner.
NGINX also works proactively to monitor performance, pointing out potentially problematic behaviors and performance bottlenecks so that future issues can be addressed beforehand.
Furthermore, if you are already using NGINX, you can adapt your existing configurations from other environments in a quick and easy manner for NGINX Ingress controller.
Traffic Management Provisions
At its core, NGINX gives you the freedom to manage your ingress and egress application traffic with a few simple steps. It facilitates certain integrations with the NGINX Service Mesh, a free service, to provide production-grade security and functionality on a unified data plane. The NGINX Service Mesh does not intrude with your tech stack, allowing it to operate freely.
API Gateway Solutions
Your NGINX Ingress controller can easily double up as your API gateway unless you plan on performing request-response manipulation in Kubernetes. Based on its feature set, your Ingress controller is capable of providing core API gateway functions such as fine-grained access control, authentication of clients, and request routing from Layers 4 to 7.
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DownloadSetting Up NGINX Ingress
The setup of NGINX ingress is made up of two phases: The first is working on setting up your Ingress Controller, and the second is defining your Ingress resources. However, there are several distinct ways of setting up your NGINX Ingress Controller. Your responsibility lies in identifying the correct methodology and making sure it aligns with your goals and priorities.
Phase 1: Introducing The NGINX Ingress Controller in The System
The first phase clearly involves the actual deployment of your controller. Your Kubernetes cluster setup will define your deployment process.
When setting up your controller, keep a few key points in mind. Begin by being aware of the version of additional support firmware, such as minikube. Older versions may require certain manual processes, thus increasing your workload. There are numerous ways to set up and deploy your NGINX controller, and this will be defined by your plan of action when running your Kubernetes applications.
Phase 2: Setting up Regulations For Your Ingress Resource
Did you successfully configure your NGINX Ingress controller? Great, now you can go about with the process of defining your Ingress resources. This step will determine the manner in which your NGINX Ingress controller acts.
Resourcing Your Ingress Controller
Every Ingress controller involves a price, even the ones that may be free and open-source. Every controller needs an investment of time, money, or both in certain cases. Certain costs are predictable based on the items you require. Other expenses are dictated by the time your team is willing to spend managing the controller you choose. Remember to account for the time as well as monetary requirements of every NGINX Ingress controller you choose.
Controlling The Risks Related To Your NGINX Ingress Controller
Your NGINX Ingress Controller has been brought in to address certain specific issues. The way you design and operate it will decide its efficacy and impact on your application. There are three major factors to consider when addressing potential areas of risk for your controller:
Security
Container or Kubernetes security concerns can often affect organizations, slowing down their ability to deploy applications. A crucial indicator to spot in such a scenario would be slow CVE patching in your controllers. Similarly, be careful while asking for assistance or advice on public forums.
Latency
The essential goal behind adopting Kubernetes is so that your organization has the ability to deploy new apps at a more rapid pace. However, your Ingress controller can add latency and slow down your application through reloads, timeouts, and errors. Keep an eye out for such issues.
Complexity
Individuals and organizations deploying containers face one significant challenge: complexity. Opting for the incorrect Ingress controller can worsen the complexity, thus having a negative impact on your app’s performance. Such erroneous measures can also limit your team’s ability to scale the department horizontally.
Choosing the right Ingress controller can define the effectiveness of your project. Keep in mind the risks your choice brings with it, and stay alert to potential security or latency issues.
Will NGINX Ingress Lay the Groundwork for Better Load Balancing?
Ingress, by itself, is an extremely powerful part of most Kubernetes applications. The NGINX Ingress Controller empowers you to standardize your security measures, find news to balance loads and give your applications the safety they deserve. We hope this article serves as a great starting point as you explore the many benefits of NGINX Ingress Controller. It is a game-changer when it comes to load balancing, especially for Kubernetes workloads.
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