Why Use an Ingress Controller? 5 Key Benefits

For teams that care about cloud efficiency, provisioning a separate cloud load balancer for every microservice quickly becomes unsustainable. The pattern doesn’t scale: costs rise, network layouts become harder to reason about, and DNS management fragments across dozens of endpoints.

An ingress controller solves this by centralizing traffic at Layer 7. Instead of attaching an external load balancer to each service, you expose hundreds of services through a single ingress endpoint. This drastically reduces cloud spend while eliminating unnecessary IPs, DNS records, and infrastructure sprawl.

Beyond cost savings, a consolidated ingress layer improves resource efficiency and gives you a more flexible way to manage application traffic. Features like path-based routing, TLS termination, rate limiting, and richer observability become part of a unified control plane, making your architecture simpler and more maintainable at scale.

Key takeaways:

• Adopt a single entry point for your cluster: An Ingress controller replaces the costly one-load-balancer-per-service model, routing all external traffic through a single IP to reduce cloud spend and simplify DNS management.
• Offload traffic management from your applications: Centralize SSL/TLS termination, routing logic, and security policies like rate limiting at the Ingress layer, freeing your backend services to focus on core business logic.
• Manage Ingress configurations declaratively: Treat your Ingress rules as code and manage them through a GitOps workflow to ensure consistency, high availability, and zero-downtime updates across your entire fleet of clusters.

What Is a Kubernetes Ingress Controller?

A Kubernetes Ingress Controller is the component responsible for managing external HTTP(S) access to services inside your cluster. It runs as a reverse proxy and becomes the primary entry point for application traffic, applying routing rules based on hostnames and URL paths. This makes it possible to expose many services through a single IP address, which is essential once your application grows beyond trivial deployments.

Unlike built-in Kubernetes components, an Ingress controller is not deployed automatically. You must choose and install one—NGINX, Traefik, HAProxy, Envoy-based controllers, and others—depending on your performance, feature, and operational needs. The controller continuously watches the Kubernetes API for Ingress objects and updates its underlying proxy configuration in real time. For teams managing multiple clusters, maintaining uniform ingress behavior can be complex. Plural’s Global Services helps by letting you define a single ingress configuration and propagate it across all targeted clusters, reducing operational drift.

How an Ingress Controller Works

An Ingress controller runs inside the cluster and is typically exposed through a LoadBalancer-type Service. Its core responsibility is to watch for changes to Ingress resources. Whenever an Ingress object is created, modified, or removed, the controller updates its internal proxy engine—such as NGINX or Traefik—to reflect the new routing directives.

For instance, you might define rules that route api.example.com to an api-service and app.example.com to a frontend-service. The Ingress controller turns these declarative rules into concrete proxy configurations. This makes traffic management a first-class part of Kubernetes rather than a collection of ad-hoc load balancer settings.

Ingress vs. Ingress Controller: What’s the Difference?

An Ingress is a Kubernetes API object that defines routing rules. It is purely declarative. A YAML file describing hosts, paths, and backend services is not enough to route traffic on its own.

An Ingress Controller is the software that reads those rules and enforces them. Without a controller, Ingress objects have no effect. The controller is the implementation backing the Ingress spec, responsible for generating and applying the actual proxy configuration.

Debunking Common Misconceptions

A common misunderstanding is that the Ingress controller creates an external load balancer. It does not. The controller is just another pod in your cluster. The external load balancer is created when you expose that controller using a LoadBalancer-type Service. Your cloud provider’s controller manager provisions the load balancer and forwards incoming traffic to the controller.

Another misconception is that Kubernetes includes an Ingress controller by default. It doesn’t. You must explicitly deploy one, selecting from the officially documented third-party implementations depending on your stack and requirements.

When to Use an Ingress Controller vs. Other Service Types

Deciding how to expose applications externally is a foundational architectural choice in Kubernetes. While Service types like LoadBalancer and NodePort provide basic connectivity, they don’t scale well for production workloads. An Ingress controller offers a more capable, flexible, and operationally efficient way to handle inbound traffic at scale. Understanding the trade-offs helps you design a cost-effective and maintainable networking model.

Ingress Controller vs. LoadBalancer

A LoadBalancer Service provisions a cloud provider’s Layer 4 load balancer for a single Kubernetes Service. This works well when you only need to expose one or two applications, but it becomes expensive and hard to manage as the number of Services grows. Each LoadBalancer Service incurs its own external load balancer and public IP, leading to both cost and operational overhead.

An Ingress controller, by contrast, runs as a Layer 7 reverse proxy inside your cluster. Although the controller is typically fronted by a single LoadBalancer Service, that one external endpoint can route traffic to hundreds of backend Services based on hostnames or paths. You still get the cloud provider’s external entry point, but you only pay for it once, and the Ingress controller handles all of the routing logic internally.

Ingress Controller vs. NodePort

A NodePort Service exposes an application by binding a port on every node. Clients must connect directly to node IPs, and you must manage port allocations yourself. This model is fine for local testing or ad-hoc debugging, but it breaks down in production where node churn, port conflicts, and hard-coded IPs introduce fragility.

An Ingress controller abstracts all of this away. You expose a single, stable endpoint—usually backed by a DNS hostname—and the controller maps incoming requests to the correct internal Service. This removes any dependence on node IPs and eliminates the operational risk of managing static port assignments across the cluster.

Improve Cost and Resource Efficiency

Using a LoadBalancer for every microservice quickly becomes cost-prohibitive. Cloud network load balancers can cost around $20 or more per month each. Multiply that by a few dozen Services and you end up with a sizable recurring expense.

An Ingress controller avoids this problem by letting all Services share a single external load balancer. It multiplexes traffic at Layer 7 and routes requests internally according to Ingress rules. You get the same external accessibility with far fewer cloud-provisioned resources, reducing both infrastructure cost and runtime overhead.

Centralize Traffic Management

Exposing each Service independently leads to scattered traffic rules, fragmented TLS management, and inconsistent security policies. An Ingress controller consolidates all inbound routing behind a single control plane. You define routing, TLS termination, and authentication declaratively through Ingress resources, and the controller enforces them uniformly across your cluster.

This centralized model simplifies configuration, improves security posture, and makes it easier to maintain consistent behavior across environments. For teams operating multiple clusters, Plural’s GitOps-driven workflows help you propagate these shared ingress configurations across your fleet, reducing configuration drift and operational toil.

Key Benefits of Using an Ingress Controller

An Ingress controller is more than a mechanism to expose services—it’s a centralized traffic management layer for your Kubernetes environment. Instead of maintaining a fleet of individual LoadBalancer Services, you route all external traffic through a single, consolidated entry point. This reduces cloud costs, simplifies your network architecture, and provides a robust control plane for routing, security, and observability. For production environments, an Ingress controller becomes the smart reverse proxy that validates, secures, and forwards traffic before it ever reaches your workloads.

Implement Advanced Traffic Routing

Ingress controllers enable routing logic well beyond what Layer 4 load balancers can support. Host-based and path-based routing let you direct different domains or URL prefixes to different Services—all through one IP. For example, api.example.com can route to an API backend while app.example.com goes to a frontend, or /api and /admin on the same domain can map to distinct Services. This centralizes routing decisions, reduces DNS sprawl, and simplifies your overall topology.

Simplify SSL/TLS Termination

Managing TLS certificates individually for each Service is both error-prone and inefficient. Ingress controllers solve this by performing TLS termination at the edge. They decrypt HTTPS traffic and forward plaintext requests over the cluster’s private network, allowing backend pods to operate without handling certificates themselves. This centralizes certificate management and reduces CPU overhead on your workloads. Operators can maintain certificates in one place—often automated through tools like cert-manager—improving both security and operational simplicity.

Ensure High Availability with Load Balancing

A built-in responsibility of Ingress controllers is to distribute traffic across healthy pods behind each Service. If a pod fails readiness or liveness checks, the controller automatically removes it from rotation, maintaining application availability during failures, node drains, or rolling updates. For scaling events or sudden traffic spikes, the controller continues balancing requests across replicas, helping sustain consistent performance and uptime.

Update Configurations with Zero Downtime

Kubernetes environments change frequently, and an Ingress controller adapts without interrupting traffic. It watches the API server and applies configuration updates dynamically, letting you modify routing rules, TLS settings, or annotations without downtime. This is critical in CI/CD workflows where Services may be deployed or updated several times a day. With GitOps tooling—such as Plural’s Continuous Deployment engine—you can manage these configurations declaratively and ensure ingress rules stay consistent across all clusters in your fleet.

Strengthen Security with Rate Limiting

An Ingress controller serves as a centralized security boundary for your cluster. It can enforce rate limits to mitigate abusive clients or DoS-style traffic before it hits your applications. Controllers also support features like IP allow/deny lists, authentication and authorization checks, and integrations with Web Application Firewalls. Consolidating these safeguards at the ingress layer simplifies compliance and reduces your attack surface by preventing unfiltered traffic from reaching backend workloads.

How to Choose and Configure an Ingress Controller

Choosing the right Ingress controller and configuring it properly determines how efficiently, securely, and reliably your Kubernetes applications handle external traffic. The controller you pick directly affects your performance envelope, your operational overhead, and your ability to scale. A structured evaluation process—combined with strong configuration and security practices—ensures your ingress layer supports production workloads instead of becoming a bottleneck.

Identify Essential Features

Start by defining the capabilities your applications require. At a minimum, ensure the controller supports host-based and path-based routing. From there, assess security features such as TLS termination, rate limiting, and optional WAF integration. Good observability is also essential: look for controllers that expose metrics compatible with Prometheus and generate logs you can easily ship into your monitoring stack. Finally, consider operational factors like configuration ergonomics, documentation quality, and community or commercial support. These influence how maintainable your ingress setup will be over time.

Assess Performance and Scalability Needs

Your Ingress controller sits in the hot path for all inbound requests, so performance matters. Estimate your expected request volume and latency budget. Some controllers focus on raw throughput and efficient resource usage, while others emphasize advanced routing or extensibility. Determine whether the controller can scale horizontally and how it behaves under traffic spikes. For large-scale or multi-cluster deployments, plan for consistent replication of the controller configuration across your environments. Platforms like Plural simplify this by managing the Ingress controller as a Global Service so each cluster receives the same configuration and scaling parameters.

Compare Popular Ingress Controllers

The Kubernetes ecosystem offers several production-grade options:

• NGINX Ingress Controller: Feature-rich, widely adopted, and backed by a strong ecosystem. Good balance of performance and configurability.
• Traefik: Known for simplicity, dynamic configuration, and automatic service discovery. Popular for small-to-medium deployments.
• Istio Ingress Gateway: Useful if you already run a service mesh and want unified traffic policies across mesh and edge.
• Kong: Functions as both an Ingress controller and an API gateway with built-in plugins for authentication, rate limiting, and transformations.

When evaluating, review the documentation, check community activity, and assess vendor support. Choose the controller that aligns with your team’s skills and your application’s routing and security needs.

Follow Configuration Best Practices

Correct configuration ensures you get the full benefit of your Ingress controller. Deploy multiple replicas to avoid a single point of failure. Use annotations or CRDs to fine-tune behavior—timeouts, protocol settings, buffer sizes, or CORS configuration. Enable readiness and liveness probes on the controller pods to ensure stable routing. Establish a consistent workflow for managing Ingress manifests. GitOps pipelines make this easy: changes flow through version control, and a deployment engine like Plural keeps all clusters synchronized with your declared state.

Address Security and Compliance

Your Ingress controller is a key security boundary, so enforce strong TLS configurations and ensure certificates remain current. Integrate with a WAF if you need protection against common web threats. Apply rate limiting and request filtering to mitigate misuse or attack traffic before it reaches your workloads. For compliance, log all inbound requests and enforce guardrails on Ingress resources. Tools like OPA Gatekeeper help apply policy controls around allowed domains, annotations, or TLS requirements. Plural extends this by distributing those validated policies across clusters, ensuring your ingress layer remains secure and compliant at scale.

Common Challenges and How to Solve Them

Deploying an Ingress controller brings powerful routing and security capabilities to your cluster, but it also introduces operational complexity. Poor configuration can lead to outages, performance regressions, and security gaps. Solving these challenges requires disciplined implementation, strong observability, and consistent security and resource management. At scale, Plural’s policy enforcement, centralized monitoring, and automated security scanning help keep these practices consistent across all clusters, reducing the risk of drift and misconfiguration. Below are the most common issues teams encounter and how to address them.

Avoiding Common Implementation Pitfalls

A frequent mistake is running Ingress controller pods without proper readiness, liveness, and startup probes. Without these checks, Kubernetes cannot determine whether the controller is healthy or ready to serve traffic. As a result, requests may be routed to unresponsive pods, causing intermittent outages. Always define all three probes so the platform can restart, delay traffic to, or drain unhealthy pods correctly.

Security misconfigurations are another common issue. Running controllers with privileged permissions, using the root user, or deploying images tagged as latest all introduce unnecessary risk. Immutable version tags ensure predictable behavior, and RBAC roles should follow the principle of least privilege. Plural uses OPA Gatekeeper to enforce these policies fleet-wide, preventing insecure configurations from being deployed.

Setting Up Monitoring and Troubleshooting

Because every external request flows through the Ingress controller, visibility is crucial. Without metrics and logs, diagnosing issues becomes guesswork. Track key metrics such as request latency, throughput, and 4xx/5xx error rates. Ensure metrics are labeled with dimensions like ingress name, backend service, and path—this granularity lets you isolate issues to a specific route or application.

Detailed logging is equally important for tracing unexpected routing behavior or backend failures. Plural’s embedded Kubernetes dashboard consolidates logs and metrics from all clusters into a single interface, eliminating the need to juggle kubeconfigs or log aggregation setups. This centralization speeds up troubleshooting and reduces operational overhead.

Optimizing Resource Management and Performance

Ingress controllers are critical workloads and require well-tuned resource requests and limits. If CPU or memory requests are too low, pods may be throttled or evicted during high traffic periods, leading to dropped or delayed requests. Analyze historical workload patterns to set realistic baselines, and revisit these settings as traffic grows.

Placement strategy is also important. Use anti-affinity rules to ensure controller pods are spread across multiple nodes, improving fault tolerance. Pod affinity can help ensure co-location with complementary workloads when needed. Plural Stacks lets you define these scheduling rules as code and apply them consistently across clusters, reducing the chance of configuration drift.

Mitigating Security Vulnerabilities

Ingress controllers sit at the edge of your infrastructure, making them a high-value target. Stay current with upstream CVEs and apply patches quickly. Incidents like the Ingress-NGINX admission webhook vulnerability highlight the need for tight configuration and proactive updates.

Limit RBAC permissions so the controller only has the access it requires. Apply network policies to restrict communication between controller pods and unrelated services. Enable strict TLS configurations and validate annotations to avoid accidental exposure or bypasses.

Plural’s built-in vulnerability scanning aggregates CVE detections across your fleet and provides a centralized dashboard for prioritizing remediation. This visibility helps teams quickly identify impacted clusters and resolve critical issues before they can be exploited.

Related Articles

• Kubernetes Ingress Controller: A Deep Dive Guide
• Ingress Kubernetes: The Ultimate 2025 Guide

Frequently Asked Questions

Do I need an Ingress controller for every cluster? For a simple development cluster running a single service, you might get by with a LoadBalancer or NodePort service. However, for any production environment or any cluster hosting multiple services, an Ingress controller is essential. It provides a centralized point for traffic management, simplifies TLS certificate handling, and significantly reduces costs by allowing many services to share a single external load balancer.

Can I run multiple Ingress controllers in the same cluster? Yes, running multiple Ingress controllers in a single cluster is a common practice. This is often done to isolate different types of traffic. For example, you might use one controller for public-facing applications and a separate, internal-only controller for backend administrative tools. You can direct traffic to the correct controller by specifying the ingressClassName field in each of your Ingress resources.

What's the difference between an Ingress controller and an API Gateway? An Ingress controller is primarily focused on routing HTTP and HTTPS traffic from outside the cluster to services within it. An API Gateway is a broader concept that often includes Ingress functionality but adds more advanced features like request authentication, rate limiting, request/response transformation, and service aggregation. Some products, like Kong or Istio's Gateway, can serve as both, blurring the lines between the two.

If my Ingress controller fails, does my entire application go down? Since the Ingress controller is the main entry point for traffic, its failure can make your applications inaccessible. This is why high availability is non-negotiable. You should always run at least two or three replicas of your Ingress controller pods. Using pod anti-affinity rules is also a best practice to ensure Kubernetes schedules these replicas on different nodes, protecting you from a single node failure.

How should I manage Ingress configurations across a large fleet of clusters? Managing Ingress rules manually across many clusters is inefficient and prone to error. The most effective approach is to adopt a GitOps workflow. By defining your Ingress resources declaratively in a Git repository, you create a single source of truth. A platform like Plural can then use its Continuous Deployment engine to automatically sync these configurations to every cluster in your fleet, ensuring consistency and simplifying rollouts.