An Introduction to the Kubernetes Gateway API

Safely sharing network infrastructure between platform and application teams is challenging in any large organization. Platform operators need to maintain control and security, while developers need the autonomy to manage routing for their specific services. The Kubernetes Gateway API addresses this directly with a role-oriented design that separates infrastructure concerns from application logic. Through distinct resources like GatewayClass, Gateway, and HTTPRoute, it creates clear boundaries of ownership. This article explores how this modular approach enables secure multi-tenancy, empowers developers, and allows platform teams to build a robust, scalable networking layer that serves the entire organization.

Key takeaways:

• Separate infrastructure from application routing: The Gateway API's primary advantage is its role-based design. Platform teams manage shared infrastructure with Gateway resources, while developers control application-specific traffic rules using Routes. This separation is critical for enabling secure, multi-tenant environments.
• Standardize advanced traffic management: Replace vendor-specific Ingress annotations with the Gateway API's portable specification for complex patterns like traffic splitting and header-based routing. This ensures your configurations are consistent and work across any compliant controller implementation.
• Automate fleet-wide configuration with GitOps: The API's modularity can lead to configuration sprawl. A GitOps platform like Plural is essential for centralizing and automating the deployment of Gateway API resources, ensuring consistency and eliminating manual errors across all your clusters.

What Is the Kubernetes Gateway API?

The Kubernetes Gateway API is an official, open-source project from the Kubernetes SIG Network that standardizes how traffic is routed into, out of, and within Kubernetes clusters. It is designed as the successor to the Kubernetes Ingress API, addressing its structural and operational limitations.

At its core, the Gateway API is a set of Kubernetes-native resources that model service networking with explicit separation of concerns:

• GatewayClass: Defines a class of data-plane implementations (e.g., controller + load balancer integration).
• Gateway: Instantiates and configures a network entry point based on a GatewayClass.
• Route resources (e.g., HTTPRoute, GRPCRoute, TCPRoute): Define application-level routing logic.

The API is intentionally role-oriented. Infrastructure providers define GatewayClasses. Platform operators provision and secure Gateways. Application teams attach Route objects that describe how traffic reaches their Services. This enforces multi-team boundaries at the API layer rather than relying on conventions or annotations.

The result is a portable, policy-driven interface that reduces reliance on controller-specific extensions and custom annotations, which historically fragmented the Ingress ecosystem.

The Rationale for Gateway API

The Gateway API emerged as Kubernetes networking requirements outgrew Ingress. Ingress was HTTP-centric, annotation-heavy, and built around a flat ownership model. It did not reflect how modern platform teams operate: centralized infrastructure governance with decentralized service ownership.

Gateway API introduces:

• A hierarchical, role-aligned resource model.
• First-class support for both Layer 4 (TCP/UDP) and Layer 7 (HTTP/gRPC) traffic.
• Stronger attachment semantics between infrastructure and routes.
• Extensibility through policy attachment and conformance profiles.

This enables safe infrastructure sharing across namespaces and teams while preserving platform control over exposure, TLS configuration, and listener constraints.

Comparison with Traditional Ingress

Ingress provided basic HTTP(S) routing into a cluster. More advanced use cases—header-based routing, traffic splitting for canaries, protocol support beyond HTTP—often required controller-specific annotations, making configurations non-portable.

The Gateway API formalizes these capabilities as structured resources:

• Traffic splitting is expressed declaratively in Route backends.
• Header and path matching are first-class fields.
• Protocol support spans HTTP, gRPC, TCP, and UDP via dedicated Route types.
• Cross-namespace attachment is governed by explicit reference policies.

Instead of embedding infrastructure and routing concerns in a single object, the Gateway API decomposes them into GatewayClass → Gateway → Route. This produces a clearer control plane contract between platform and application teams and results in a more scalable, policy-aware networking model for production Kubernetes environments.

Gateway API vs. Ingress: What’s the Difference?

The Kubernetes Gateway API is the architectural successor to the Kubernetes Ingress API. Ingress standardized basic HTTP(S) exposure for Services, but its design assumptions no longer hold in multi-team, multi-tenant clusters.

Ingress centers around a single resource that combines infrastructure configuration (e.g., TLS, entrypoints) and application routing (paths, hosts). As clusters scale, this coupling becomes an operational bottleneck and a security liability. Gateway API decomposes these concerns into explicit, role-aligned resources, producing a more enforceable and portable model.

For platform and DevOps teams, this is not a cosmetic upgrade. It is a shift from a flat, annotation-driven interface to a composable API with formal ownership boundaries.

Where the Ingress API Falls Short

1. Monolithic resource model
Ingress conflates infrastructure and routing logic. Modifying a path rule often requires permissions on the entire Ingress object, which may also control TLS termination and load balancer settings. Fine-grained RBAC delegation is difficult.

2. Annotation-driven extensibility
The core Ingress spec is intentionally minimal. Advanced behaviors—traffic splitting, header matching, rewrites—are typically implemented via controller-specific annotations. These annotations:

• Are not standardized
• Differ across controllers
• Reduce portability
• Increase vendor lock-in risk

3. Limited protocol scope
Ingress is primarily HTTP(S)-centric. Non-HTTP use cases (TCP/UDP) depend heavily on implementation-specific extensions.

In practice, complex production deployments require features that the base Ingress API never formally modeled.

How the Gateway API Improves on Ingress

Gateway API introduces a role-oriented resource hierarchy:

• GatewayClass: Infrastructure provider abstraction.
• Gateway: Instantiated data-plane entrypoint managed by platform teams.
• Route types (HTTPRoute, GRPCRoute, TCPRoute, etc.): Application-owned routing rules.

This separation enables:

• Delegated routing control without exposing infrastructure configuration.
• Safer multi-namespace attachment via explicit references.
• First-class support for traffic weighting and advanced match conditions.
• Layer 4 and Layer 7 protocol support.
• Conformance-based portability across compliant implementations.

Instead of relying on opaque annotations, advanced routing semantics are expressed as structured fields in Route resources. This produces declarative, auditable, and portable configurations.

Planning a Migration from Ingress

Migration is structural, not mechanical. There is no 1:1 object replacement.

A typical transition strategy:

1. Install Gateway API CRDs
   Gateway API resources are distributed as CRDs and must be installed explicitly.
2. Select a compliant implementation
   Examples include Contour, Istio, or NGINX-based controllers that support Gateway API.
3. Map responsibilities
   • Define GatewayClasses (platform-owned).
   • Provision Gateways for specific exposure patterns.
   • Translate Ingress routing rules into HTTPRoute (or other Route types).
4. Migrate incrementally
   Start with non-critical services. Validate listener configuration, TLS handling, and traffic policies before broader rollout.

The key mindset shift: Ingress configurations become distributed across infrastructure and routing resources. This decomposition is the core value proposition, not just new syntax.

For organizations standardizing on modern Kubernetes networking, Gateway API provides a scalable control-plane contract aligned with real-world team boundaries.

Understanding the Core Components

The Gateway API introduces a role-oriented and extensible model for managing traffic. It breaks down the monolithic Ingress resource into several distinct, collaborative components. Understanding these core resources is the first step to effectively using the API. Each component serves a specific purpose, from defining infrastructure templates to routing application traffic, allowing different teams to manage their part of the networking stack independently.

GatewayClass: The Template for Gateways

Think of a GatewayClass as a template or blueprint for creating gateways. It defines a set of gateways that share a common configuration and are managed by a single controller. As the official Kubernetes documentation states, "GatewayClass serves as a blueprint for defining a group of Gateways that share common settings." This resource is typically managed by a cluster administrator or infrastructure provider. For example, a provider might offer a GatewayClass named aws-nlb that provisions an AWS Network Load Balancer, while another named internal-envoy provisions an in-cluster Envoy proxy. This allows platform teams to offer standardized, pre-configured gateway types for different use cases across the organization.

Gateway: The Entry Point for Traffic

A Gateway is a specific instance created from a GatewayClass. It represents the actual network infrastructure that listens for and processes traffic. When a platform operator creates a Gateway resource, they specify which GatewayClass to use, which in turn provisions the underlying load balancer or proxy. "A Gateway represents the actual network entry point for traffic," handling incoming requests and directing them into the cluster. For example, an operator might create a Gateway for the finance department's applications that listens on port 443 for HTTPS traffic, effectively creating a dedicated, IP-addressable entry point for that team's services without exposing them directly.

Routes: How Traffic is Directed

Routes define how requests that arrive at a Gateway are mapped to specific services within the cluster, a task typically managed by application developers. The most common type is HTTPRoute, which handles HTTP and HTTPS traffic. As the Kubernetes documentation explains, "HTTPRoute defines the rules for directing web traffic...from a Gateway to specific applications." For instance, a developer can create an HTTPRoute rule specifying that all traffic for the /login path should be routed to the login-service. This separation of concerns empowers developers to manage their application's routing logic without needing to modify the underlying, shared gateway infrastructure.

Policy Attachment: Extending Gateway Capabilities

Policy Attachment is a powerful feature that allows you to attach specific behaviors, like security or traffic management rules, to Gateways and Routes. This is a key area where the Gateway API’s extensibility shines. Policies are implemented as Custom Resources (CRDs), enabling fine-grained control over the request lifecycle. As the Gateway API introduction explains, this model "facilitates the sharing of network infrastructure...while allowing network owners to maintain control." For example, a security team could attach a TimeoutPolicy to a Gateway to enforce a default request timeout, or an AuthenticationPolicy to ensure all incoming traffic is validated before reaching any backend service.

Common Use Cases for the Gateway API

The Gateway API isn't just a replacement for Ingress; it's a fundamental shift in how Kubernetes networking is managed. Its expressive, role-oriented design unlocks several powerful use cases that were previously complex or required custom tooling. By separating infrastructure concerns from application routing, teams can build more scalable, secure, and flexible systems. For platform teams managing large fleets, this separation is critical for maintaining control while empowering developers. The Gateway API provides the standardized framework, and a platform like Plural provides the automation to manage these configurations consistently across all your clusters using a GitOps-based workflow.

Manage Multi-Tenant Traffic

One of the most significant advantages of the Gateway API is its native support for multi-tenancy. In large organizations, multiple teams often share the same Kubernetes clusters and network infrastructure. The Gateway API's role-based resource model allows platform administrators to safely delegate routing configuration. Infrastructure providers can define GatewayClass resources, cluster operators can provision Gateway resources that expose specific ports and protocols, and application developers can independently manage HTTPRoute or GRPCRoute resources to direct traffic to their services. This clear separation of concerns helps organizations share network infrastructure safely, preventing one team's configuration changes from impacting another's.

Implement Advanced Routing and Traffic Splitting

The Gateway API provides granular control over traffic flow, making it ideal for advanced deployment strategies. Unlike the Ingress API, which has limited routing capabilities, the Gateway API can handle advanced routing rules out of the box. You can implement traffic splitting based on weights for canary releases or A/B testing, direct requests based on HTTP headers or query parameters, and even mirror traffic to a different service for analysis. For example, you can route 95% of traffic to a stable application version while sending 5% to a new version, all defined within a single HTTPRoute manifest. This expressiveness eliminates the need for complex, annotation-based workarounds common with Ingress.

Integrate with a Service Mesh

The Gateway API is designed to unify traffic management for both north-south (ingress) and east-west (service-to-service) traffic. Through the GAMMA initiative, the API provides a standard interface for service meshes. This allows you to use the same Route resources, like HTTPRoute, to manage traffic within your cluster. Instead of attaching a route to a Gateway, you can attach it directly to a Service, letting the service mesh handle the routing logic. This creates a consistent experience for developers, who no longer need to learn separate configuration models for ingress controllers and service meshes, simplifying the overall operational complexity of the network stack.

Enhance Security and Protocol Support

The Gateway API extends beyond basic HTTP/S traffic, offering first-class support for a variety of protocols through different Route types. The specification includes HTTPRoute, GRPCRoute, TCPRoute, and UDPRoute, allowing you to manage different kinds of application traffic with a consistent API. Furthermore, the PolicyAttachment mechanism enables fine-grained security controls. You can attach policies to Gateways or Routes to enforce TLS settings, authentication requirements, rate limiting, or custom security rules. This extensibility ensures that as your security and protocol needs evolve, the Gateway API can adapt without requiring fundamental changes to your routing configurations.

How to Get Started with the Gateway API

Adopting the Gateway API is a structured process that involves setting up the foundational components, selecting an implementation that fits your environment, and deploying a basic configuration to see it in action. Unlike the built-in Ingress API, the Gateway API is not available by default in a Kubernetes cluster. You must actively install and configure it. This process begins with adding the necessary Custom Resource Definitions (CRDs) to your cluster, which allows Kubernetes to understand and manage Gateway API resources like Gateway, GatewayClass, and HTTPRoute.

Once the CRDs are in place, the next critical step is choosing a controller that implements the Gateway API specification. This choice will depend on your cloud provider, existing infrastructure, and specific feature requirements. With a controller running, you can then walk through a basic setup, defining a Gateway to handle inbound traffic and a Route to direct that traffic to a backend service. Following these steps provides a clear path to integrating this powerful networking standard into your Kubernetes environment.

Step 1: Install the Necessary CRDs

Before you can create any Gateway API resources, you must first install the Custom Resource Definitions (CRDs) that define them. These CRDs extend the Kubernetes API, teaching your cluster about new object types like GatewayClass, Gateway, and various Route resources. The installation is typically a straightforward process involving a single kubectl apply command. The official Kubernetes documentation provides the necessary manifest files and instructions. Installing these CRDs is a prerequisite for any Gateway API controller, as the controller relies on these definitions to function correctly. This step ensures that your cluster's control plane can recognize, validate, and store Gateway API objects.

Step 2: Choose Your Gateway Implementation

The Gateway API is a specification, not a single piece of software. This means you need to choose a controller that implements the API's standards. Many different projects, from cloud provider load balancers to standalone ingress controllers and service meshes, offer their own implementations. Your choice will depend on factors like your cloud environment (e.g., GKE, EKS), performance needs, and desired feature set, such as advanced traffic splitting or specific security protocols. The official project maintains a comprehensive list of implementations to help you evaluate which controller best fits your stack. Each implementation will have its own installation process and specific annotations or configurations.

Step 3: Walk Through a Basic Configuration

After installing the CRDs and a controller, you can create your first Gateway. A typical workflow involves three main resources. First, a platform administrator defines a GatewayClass, which serves as a template for creating Gateways. Next, an operator creates a Gateway resource, requesting a load balancer that listens on a specific port. Finally, a developer creates an HTTPRoute (or another route type) to direct traffic from the Gateway to a specific application Service. To get a feel for this process, it's helpful to follow a getting-started guide for your chosen implementation and review the core API concepts to understand the roles and interactions between these resources.

Common Challenges to Watch For

While the Gateway API offers a significant upgrade over Ingress, its adoption introduces new operational hurdles. The increased flexibility and modularity come with a steeper learning curve and potential for misconfiguration. As your teams begin to implement the Gateway API, it's important to anticipate challenges related to configuration management, implementation consistency, and performance troubleshooting. Addressing these areas proactively ensures a smoother transition and helps you realize the full benefits of this powerful networking standard.

Managing Configuration Complexity

The Gateway API splits networking configuration across multiple CRDs like Gateway, HTTPRoute, and TCPRoute. While powerful, this can lead to configuration sprawl. As the CNCF notes, this fragmented setup can create operational challenges like managing dozens of YAML files and ensuring consistency. Without proper tooling, tracking relationships between Gateways and Routes becomes difficult, increasing the risk of misconfiguration. A GitOps-based platform like Plural centralizes these configurations, providing a single source of truth and automating deployments to maintain consistency across your fleet.

Handling Implementation Inconsistencies

As a specification, the Gateway API's behavior can vary between implementations like Istio, Contour, or GKE, leading to inconsistencies across a fleet. A common pitfall is creating giant, complex configuration files that undermine the API's role-based separation, reintroducing management issues found with Ingress. This lack of standardization complicates security and governance. Plural helps enforce consistency by allowing you to automate manifest generation and deployments, ensuring every cluster adheres to a predefined, version-controlled standard.

Troubleshooting Performance

Advanced routing capabilities like traffic splitting introduce new layers of complexity to troubleshooting. A performance issue could originate from the Gateway controller, a misconfigured Route, or the backend service. Pinpointing the root cause requires deep visibility into the entire request path, which can complicate troubleshooting efforts. Without a unified view, engineers must jump between tools to correlate data. Plural’s embedded Kubernetes dashboard provides a single pane of glass for observability, allowing teams to inspect Gateway resources, check route statuses, and analyze traffic flow from one central console.

Best Practices for Implementation

The Gateway API offers a powerful and flexible model for managing traffic, but its effectiveness depends on a well-planned implementation. Adopting a few key best practices from the start will help you build a scalable, secure, and maintainable networking layer for your applications. These practices focus on resource organization, security controls, and protocol management to ensure your gateway infrastructure remains robust as your environment grows. By establishing clear patterns for how your teams interact with gateway resources, you can avoid common pitfalls and make the most of the API's expressive capabilities.

Organize Resources and Namespaces

Proper organization is fundamental to managing a multi-tenant Kubernetes environment. By default, a Gateway will only accept traffic rules from the same Kubernetes namespace. This is a deliberate security feature that prevents teams from accidentally or maliciously interfering with each other's traffic. To allow Routes from other namespaces, you must explicitly configure it using the allowedRoutes field in the Gateway specification.

A solid best practice is to deploy Gateway resources into a dedicated infrastructure namespace managed by the platform team. Then, you can configure each Gateway to allow application teams to create HTTPRoute resources in their own namespaces. This model aligns with the API's role-based design, giving developers autonomy over their application routing without granting them control over shared infrastructure.

Configure Security and RBAC

The Gateway API is designed with a clear separation of roles in mind: platform administrators manage the infrastructure (GatewayClass, Gateway), while application developers manage routing (HTTPRoute, GRPCRoute). You should enforce this separation using Kubernetes Role-Based Access Control (RBAC). Create ClusterRoles that grant platform admins permissions to manage gateway infrastructure across the cluster, and create namespace-scoped Roles that allow developers to manage only the Route resources within their designated namespaces.

Managing these policies across many clusters can become complex. Plural simplifies this by allowing you to define and sync fleet-wide RBAC policies from a central Git repository. The Plural console uses Kubernetes impersonation, which means you can configure access based on user emails or groups from your identity provider, creating an effective and secure SSO experience.

Manage Multiple Protocols

One of the key advantages of the Kubernetes Gateway API is its native support for multiple protocols. Unlike Ingress, which is primarily focused on HTTP/S, the Gateway API uses distinct resources like HTTPRoute, GRPCRoute, TCPRoute, and UDPRoute to manage different types of traffic. This expressiveness allows you to handle advanced traffic rules, such as routing gRPC calls to a specific backend or forwarding raw TCP traffic for a database.

To maintain consistency, establish clear conventions for your teams. For example, mandate that all internal microservices communicating over gRPC must use GRPCRoute. This prevents configuration drift where different teams solve the same problem in different ways. Standardizing on specific Route types for particular use cases makes your configuration easier to understand, manage, and troubleshoot at scale.

Manage the Gateway API at Scale with Plural

While the Gateway API introduces a more robust and flexible model for traffic management, deploying and maintaining it across a large fleet of Kubernetes clusters presents its own set of operational challenges. Ensuring consistent configurations, managing role-based access, and troubleshooting traffic flow in a distributed environment can quickly become complex. Without the right tooling, teams can find themselves spending more time managing the infrastructure than leveraging its benefits.

This is where a unified management platform becomes critical. Plural provides the centralized control and automation needed to effectively manage Gateway API resources at scale. By integrating fleet management, GitOps-based continuous deployment, and observability into a single console, Plural helps platform teams streamline operations, reduce configuration drift, and empower developers to work more efficiently. Instead of wrestling with disparate tools and manual processes, you can implement a consistent, secure, and scalable approach to traffic management across your entire Kubernetes landscape.

Unify Fleet Management from a Single Console

Managing Gateway API resources across dozens or hundreds of clusters requires a centralized point of control. Constantly switching contexts and using kubectl for individual clusters is inefficient and error-prone. Plural provides a unified console that gives you a single pane of glass for your entire Kubernetes fleet. From this dashboard, you can view, manage, and troubleshoot Gateway, GatewayClass, and Route resources across all environments without needing to juggle kubeconfigs or VPN access.

This centralized approach simplifies day-to-day operations by providing a consistent interface for all clusters, whether they are in different cloud providers or on-premises. Plural’s embedded Kubernetes dashboard uses an auth proxy to securely access cluster APIs, allowing you to inspect resource status and configurations directly. This helps you maintain consistency and enforce standards for your Gateway API implementation across the organization, reducing operational overhead and improving reliability.

Automate Gateway Configurations with GitOps

Manual configuration of Gateway API resources is not scalable and often leads to inconsistencies. A GitOps workflow is the standard for managing Kubernetes configurations reliably, and Plural CD is built around this principle. By defining your Gateway API resources as code in a Git repository, you create a single source of truth for your entire traffic routing configuration. Plural’s agent, installed in each managed cluster, automatically pulls and applies these configurations, ensuring your clusters always reflect the desired state defined in Git.

This GitOps-based automation eliminates configuration drift and makes changes auditable and reversible. When a new route needs to be added or a traffic-splitting policy updated, you simply submit a pull request. This process integrates seamlessly with existing developer workflows and provides a clear audit trail for every change. Using Plural Stacks, you can even manage the underlying infrastructure for your gateway controller, like load balancers and IAM policies, through the same declarative, API-driven approach.

Simplify Troubleshooting and Monitoring

The layered structure of the Gateway API provides detailed status conditions that are invaluable for debugging, but accessing and interpreting this information across a fleet can be difficult. Plural simplifies this process by centralizing observability within its console. You can quickly identify misconfigured resources or traffic routing issues when you inspect the status of Gateways and Routes without needing to execute complex CLI commands against each cluster.

Plural’s console gives you direct visibility into the events and logs associated with your gateway controller and application pods. This makes it easier to perform root cause analysis when traffic isn't flowing as expected. For example, you can trace a request from the Gateway through the associated Route to the backend Service, checking the status at each hop. This integrated troubleshooting experience reduces the mean time to resolution (MTTR) and empowers engineers to solve problems independently.

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Frequently Asked Questions

If my current Ingress setup works, why should I switch to the Gateway API? While a functional Ingress setup can handle basic routing, it often relies on non-standard annotations for anything beyond simple host and path matching. This creates vendor lock-in and makes configurations brittle. The Gateway API provides a standardized, portable way to manage advanced traffic patterns like canary releases, header-based routing, and traffic splitting. Its role-oriented design also allows you to safely delegate routing controls to application teams without giving them access to critical infrastructure, which is a significant security and operational improvement over the monolithic Ingress model.

Is the Gateway API ready for production use? Yes, the core components of the Gateway API, including GatewayClass, Gateway, and HTTPRoute, are officially stable and have graduated to General Availability (GA). This signifies that the API is mature, well-supported, and considered ready for production workloads. Many popular ingress controllers and service meshes have already released GA-level implementations, providing a robust ecosystem of tools to choose from.

How does the Gateway API change the workflow between platform and application teams? The Gateway API formalizes the separation of responsibilities that many platform teams already try to enforce. Platform engineers can now focus on managing the underlying infrastructure by defining GatewayClass and Gateway resources, which control load balancers and TLS termination. Application developers are then empowered to manage their own traffic routing by creating HTTPRoute resources within their own namespaces. This clear boundary, enforced by the API itself, reduces friction and eliminates the need for developers to request changes to a central, shared Ingress object.

Do I need a service mesh to use the Gateway API? No, you do not need a service mesh to use the Gateway API for ingress (north-south) traffic. The API is designed to be a standalone solution for managing traffic entering your cluster, serving as a more powerful replacement for the Ingress API. However, the Gateway API is also designed to integrate with service meshes to provide a unified configuration model for both ingress and service-to-service (east-west) traffic, but this is an optional, advanced use case.

Can I use my existing Ingress controller with the Gateway API? It depends on the controller. The Gateway API is a distinct specification, and an Ingress controller must have a specific implementation to support it. Many popular controllers, such as NGINX, Contour, and Istio, have developed Gateway API implementations. You will need to check the documentation for your specific controller to see if it supports the Gateway API and what steps are required to enable it. In most cases, you will need to install the Gateway API CRDs and deploy a new version or configuration of the controller.