Streaming
beta

Configure External Access through Gateway API

Expose your Redpanda cluster to external clients through a single Gateway API entry point instead of NodePort or LoadBalancer Services. Clients connect to one static Gateway address, and the Gateway routes each connection to the right broker using TLS Server Name Indication (SNI), so you avoid per-broker LoadBalancers and node port management.

This feature is in beta. The configuration surface (external.gateway and the per-listener type field) may change before general availability. Beta features are not recommended for production environments. To give feedback, reach out to the Redpanda team in Redpanda Community Slack.

After reading this page, you will be able to:

  • Choose between TLS passthrough and TLS termination for Gateway-routed listeners

  • Deploy a Gateway and configure Redpanda listeners to route through it

  • Diagnose TLSRoute and Gateway connectivity failures

How it works

You bring your own Gateway: deploy a Gateway API implementation that supports TLSRoute, and create a Gateway resource with a TLS listener (see Deploy a Gateway). Redpanda then creates the routing configuration for you:

  • A bootstrap TLSRoute and Service: Clients make their first connection to a single hostname, such as redpanda.example.com. The bootstrap Service targets all brokers, so initial connections are spread across the cluster.

  • A TLSRoute and Service per broker: After the initial connection, Kafka clients reconnect to individual brokers using the per-broker hostnames that the brokers advertise, such as redpanda-0-broker.example.com. The Gateway routes each connection to the right broker by matching the SNI hostname.

All traffic enters through the Gateway’s listener port, and brokers advertise that port (443 by default) to clients. The Gateway either forwards each TLS connection unchanged to the broker (passthrough) or decrypts it and forwards the plain connection (termination). See Choose a TLS mode.

Each external listener opts in independently with type: tlsroute, so you can migrate from NodePort or LoadBalancer Services one listener at a time: listeners without type: tlsroute keep using the conventional Service, and listeners with it are excluded from that Service.

Choose a TLS mode

The Gateway listener’s tls.mode determines where TLS ends. Redpanda creates the same TLSRoutes in both modes: the difference lives in the Gateway listener and in the Redpanda listener’s TLS configuration.

Passthrough (recommended) Termination

How it works

The Gateway forwards the encrypted connection to the broker, and the broker presents its own certificate to the client.

The Gateway decrypts the connection with its own certificate and forwards unencrypted traffic to the broker.

Encryption

End-to-end TLS from client to broker.

TLS ends at the Gateway. Traffic between the Gateway and the brokers is unencrypted.

Certificates

The broker certificates must include the bootstrap and per-broker hostnames. Redpanda adds these Subject Alternative Names (SANs) automatically to cert-manager-managed certificates.

One certificate on the Gateway covers all hostnames. The broker certificates are not involved.

Client authentication

mTLS and SASL both work.

mTLS is not available because the brokers never see the client’s TLS session. Use SASL.

Gateway support

Supported by all TLSRoute-capable Gateway implementations.

Optional in the Gateway API specification. Requires an implementation that supports TLS termination for TLSRoute, such as Envoy Gateway 1.8 or later. Check your implementation’s documentation.

Choose passthrough unless you need to manage client-facing certificates centrally at the Gateway and can accept unencrypted traffic between the Gateway and the brokers.

Prerequisites

  • Redpanda Operator 26.2 or later, or Redpanda Helm chart 26.2.0 or later.

    Install or upgrade the operator:

    helm repo add redpanda https://charts.redpanda.com
helm repo update
helm upgrade --install redpanda-operator redpanda/operator \
  --namespace <namespace> --create-namespace \
  --version v26.2.1 \
  --set crds.enabled=true

    No published Redpanda Helm chart includes this feature yet. If you deploy with the Helm chart rather than the Operator, wait for the 26.2 chart release.

  • A supported Kubernetes version. The Gateway API 1.5 CRDs fail to install on API servers earlier than Kubernetes 1.31. For the version support policy, see the Gateway API versioning documentation.

  • The Gateway API CRDs, version 1.5 or later, installed from a release channel that includes TLSRoute. Redpanda creates TLSRoute resources from the generally available (GA) gateway.networking.k8s.io/v1 API, which is available in Gateway API 1.5. For installation steps, see the Gateway API getting started guide.

  • A Gateway controller that supports TLSRoute, such as Envoy Gateway or Istio. Redpanda does not create the Gateway resource. See Deploy a Gateway.

    Use a controller version that watches TLSRoute at the GA gateway.networking.k8s.io/v1 API, because Redpanda creates its routes at v1. For Envoy Gateway, this means version 1.8 or later: earlier versions log TLSRoute CRD not found, skipping TLSRoute watch and never attach the routes.

    If your controller bundles its own Gateway API CRDs, install it without them (for example, helm install --skip-crds for Envoy Gateway) so it uses your Gateway API 1.5 CRDs. For installation details, see your controller’s documentation, such as the Envoy Gateway installation guide.

  • TLS between clients and the Gateway. The Gateway routes connections by SNI, which requires clients to connect with TLS in both modes. With passthrough, enable TLS on every Redpanda listener that you route through the Gateway. If you use cert-manager-managed certificates, Redpanda automatically adds the bootstrap and per-broker hostnames to the certificate’s SANs. With termination, the Gateway presents its own certificate instead. See Choose a TLS mode.

  • Control over DNS for your chosen hostnames. The bootstrap hostname and all per-broker hostnames must resolve to the Gateway’s external address.

  • Install rpk on your local machine so that you can test connections from outside Kubernetes.

Deploy a Gateway

Redpanda attaches its TLSRoutes to a Gateway that you deploy and manage.

  1. If your Gateway controller does not create a GatewayClass, create one. Get the controllerName value from your controller’s documentation. For example, for Envoy Gateway:

    apiVersion: gateway.networking.k8s.io/v1
kind: GatewayClass
metadata:
  name: envoy
spec:
  controllerName: gateway.envoyproxy.io/gatewayclass-controller

  2. Create a Gateway with a TLS listener in your chosen mode. See Choose a TLS mode.

    • TLS passthrough

    • TLS termination

    gateway.yaml
    apiVersion: gateway.networking.k8s.io/v1
kind: Gateway
metadata:
  name: redpanda-gateway
  namespace: <namespace>
spec:
  gatewayClassName: envoy (1)
  listeners:
    - name: kafka (2)
      protocol: TLS
      port: 443 (3)
      tls:
        mode: Passthrough (4)
      allowedRoutes:
        kinds:
          - kind: TLSRoute
            group: gateway.networking.k8s.io
    1 The name of your GatewayClass.
    2 The listener name. Reference it later in external.gateway.parentRefs[].sectionName.
    3 The port that clients connect to. Brokers advertise external.gateway.advertisedPort (443 by default), so keep the two in sync.
    4 The Gateway forwards TLS connections to the brokers unchanged.

    The Gateway needs a certificate whose SANs cover the bootstrap hostname and all per-broker hostnames, either listed individually or through a wildcard. This example issues one with cert-manager:

    gateway-certificate.yaml
    apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  name: gateway-tls-cert
  namespace: <namespace>
spec:
  secretName: gateway-tls-cert
  dnsNames:
    - redpanda.example.com (1)
    - redpanda-0-broker.example.com (2)
    - redpanda-1-broker.example.com
    - redpanda-2-broker.example.com
  issuerRef:
    name: <issuer-name>
    kind: Issuer
    1 The bootstrap hostname.
    2 One entry per broker, or a wildcard such as *.example.com that covers them all.
    gateway.yaml
    apiVersion: gateway.networking.k8s.io/v1
kind: Gateway
metadata:
  name: redpanda-gateway
  namespace: <namespace>
spec:
  gatewayClassName: envoy
  listeners:
    - name: kafka
      protocol: TLS
      port: 443
      tls:
        mode: Terminate (1)
        certificateRefs:
          - name: gateway-tls-cert (2)
      allowedRoutes:
        kinds:
          - kind: TLSRoute
            group: gateway.networking.k8s.io
    1 The Gateway decrypts client connections and forwards unencrypted traffic to the brokers.
    2 The Secret that contains the certificate the Gateway presents to clients.

  3. Apply the manifests and verify that the Gateway controller accepts the listener:

    kubectl apply -f gateway.yaml --namespace <namespace>

kubectl get gateway redpanda-gateway --namespace <namespace> \
  -o jsonpath='{range .status.listeners[*]}{.name}: {range .conditions[*]}{.type}={.status} {end}{"\n"}{end}'

    The listener reports Accepted=True and Programmed=True. The Gateway’s external address comes from your Gateway implementation, typically through a LoadBalancer Service that it provisions.

Configure Redpanda listeners for the Gateway

Opt each external listener into Gateway routing and point Redpanda at the Gateway you deployed.

  1. Enable gateway mode and reference your Gateway.

    • Operator

    • Helm

    redpanda-cluster.yaml
    apiVersion: cluster.redpanda.com/v1alpha2
kind: Redpanda
metadata:
  name: redpanda
spec:
  clusterSpec:
    external:
      enabled: true
      gateway:
        enabled: true
        parentRefs:
          - name: <gateway-name> (1)
            namespace: <gateway-namespace>
            sectionName: <gateway-listener-name> (2)
    tls:
      enabled: true
      certs:
        default:
          caEnabled: true
    listeners:
      kafka:
        external:
          default:
            port: 9094
            type: tlsroute (3)
            host: redpanda.example.com (4)
            hostTemplate: redpanda-$POD_ORDINAL-broker.example.com (5)
            tls:
              cert: default
    1 The name of the Gateway resource that you deployed. At least one parentRefs entry is required.
    2 Optional: The name of the TLS listener on the Gateway.
    3 Routes this listener through the Gateway and excludes it from the NodePort or LoadBalancer Service.
    4 The bootstrap hostname that clients use for their first connection.
    5 The per-broker hostname pattern. $POD_ORDINAL is replaced with the broker’s ordinal, and $POD_NAME with the Pod name. Required for Kafka listeners when you run more than one broker. 
    kubectl apply -f redpanda-cluster.yaml --namespace <namespace>
    Requires Redpanda Helm chart 26.2.0 or later.
    gateway-values.yaml
    external:
  enabled: true
  gateway:
    enabled: true
    parentRefs:
      - name: <gateway-name> (1)
        namespace: <gateway-namespace>
        sectionName: <gateway-listener-name> (2)
tls:
  enabled: true
  certs:
    default:
      caEnabled: true
listeners:
  kafka:
    external:
      default:
        port: 9094
        type: tlsroute (3)
        host: redpanda.example.com (4)
        hostTemplate: redpanda-$POD_ORDINAL-broker.example.com (5)
        tls:
          cert: default
    1 The name of the Gateway resource that you deployed. At least one parentRefs entry is required.
    2 Optional: The name of the TLS listener on the Gateway.
    3 Routes this listener through the Gateway and excludes it from the NodePort or LoadBalancer Service.
    4 The bootstrap hostname that clients use for their first connection.
    5 The per-broker hostname pattern. $POD_ORDINAL is replaced with the broker’s ordinal, and $POD_NAME with the Pod name. Required for Kafka listeners when you run more than one broker. 
    helm upgrade --install redpanda redpanda/redpanda \
  --namespace <namespace> --create-namespace \
  --values gateway-values.yaml

    By default, brokers advertise port 443 to clients. If your Gateway listens on a different port, set external.gateway.advertisedPort.

    If your Gateway listener terminates TLS, disable TLS on the Redpanda listener instead of referencing a certificate, because connections arrive at the brokers already decrypted:

    listeners:
  kafka:
    external:
      default:
        port: 9094
        type: tlsroute
        host: redpanda.example.com
        hostTemplate: redpanda-$POD_ORDINAL-broker.example.com
        tls:
          enabled: false

  2. Create DNS records that resolve the bootstrap hostname and all per-broker hostnames to your Gateway’s external address. A wildcard record such as *.example.com covers both.

  3. Verify that Redpanda created the TLSRoutes and that the Gateway accepted them:

    kubectl get tlsroutes --namespace <namespace> \
  -o custom-columns='NAME:.metadata.name,HOSTNAMES:.spec.hostnames'
    Plain kubectl get tlsroutes prints only the NAME and AGE columns. Use this command’s custom-columns output (or -o yaml) to see the hostnames.

    For a three-broker cluster named redpanda, expect a bootstrap route and one route per broker:

    NAME                               HOSTNAMES
redpanda-kafka-default-0           [redpanda-0-broker.example.com]
redpanda-kafka-default-1           [redpanda-1-broker.example.com]
redpanda-kafka-default-2           [redpanda-2-broker.example.com]
redpanda-kafka-default-bootstrap   [redpanda.example.com]

    Check that each route’s status.parents reports Accepted: True from your Gateway controller:

    kubectl get tlsroute <route-name> --namespace <namespace> -o jsonpath='{.status.parents}'
    Example: what Redpanda creates for this listener

    Each TLSRoute attaches to your Gateway listener through parentRefs, matches one SNI hostname, and points at a Redpanda-created ClusterIP Service. The bootstrap route targets a Service that load-balances across all brokers (<cluster-name>-gateway-bootstrap), and each per-broker route, such as redpanda-kafka-default-0, targets that broker’s own Service (gw-<cluster-name>-<ordinal>):

    apiVersion: gateway.networking.k8s.io/v1
kind: TLSRoute
metadata:
  name: redpanda-kafka-default-bootstrap
  namespace: <namespace>
spec:
  hostnames:
    - redpanda.example.com # the SNI hostname that the Gateway matches
  parentRefs:
    - group: gateway.networking.k8s.io
      kind: Gateway
      name: redpanda-gateway
      sectionName: kafka # the Gateway listener to attach to
  rules:
    - backendRefs:
        - kind: Service
          name: redpanda-gateway-bootstrap
          port: 9094 # the Redpanda listener port, not the advertised port

    The routes are identical in passthrough and termination modes. A TLSRoute describes only SNI-based routing to a backend Service. The TLS mode lives on the Gateway listener.

  4. Test the connection from outside the Kubernetes cluster:

    rpk cluster info \
  -X brokers=redpanda.example.com:443 \
  -X tls.enabled=true \
  -X tls.ca=ca.crt

    The broker list shows the per-broker hostnames with the advertised port.

    The certificate authority (CA) to pass in tls.ca depends on the TLS mode. With passthrough, use the CA of the broker certificates. With termination, use the CA of the Gateway’s certificate.

Route other listeners through the Gateway

You can route the HTTP Proxy, Admin API, and Schema Registry listeners through the same Gateway with type: tlsroute and the same host field. For these listeners, hostTemplate is optional: without it, Redpanda creates only the bootstrap route, and the Gateway load-balances requests across brokers. Give each listener a unique hostname:

listeners:
  kafka:
    external:
      default:
        port: 9094
        type: tlsroute
        host: redpanda.example.com
        hostTemplate: redpanda-$POD_ORDINAL-broker.example.com
        tls:
          cert: default
  http:
    external:
      default:
        port: 8082
        type: tlsroute
        host: proxy.example.com
        tls:
          cert: default
  schemaRegistry:
    external:
      default:
        port: 8081
        type: tlsroute
        host: schema.example.com
        tls:
          cert: default

Migrate from NodePort or LoadBalancer Services

The per-listener type field lets conventional and Gateway-routed listeners coexist, so you can migrate with no downtime:

  1. Add a new external listener with type: tlsroute on a different port, alongside your existing listener.

  2. Point new clients, or a subset of clients, at the bootstrap hostname and verify connectivity.

  3. Move the remaining clients over.

  4. Remove the old external listener. When no listeners use the conventional Service, remove external.type and the associated NodePort or LoadBalancer configuration.

Configuration validation

Redpanda refuses to render configurations that would silently break connectivity:

  • A listener with type: tlsroute requires external.gateway.enabled: true with at least one parentRefs entry. The listener is never placed in a NodePort or LoadBalancer Service as a fallback.

  • Every Gateway-routed listener requires host.

  • A Kafka listener with more than one broker requires hostTemplate, because Kafka clients must reconnect to individual brokers.

If any of these conditions fail, the Helm release or Redpanda resource fails with an error that names the listener.

Troubleshoot

Here are some common troubleshooting scenarios and their solutions. For more troubleshooting steps, see Resolve Errors in Kubernetes.

Clients connect to the bootstrap hostname but fail on reconnect: The per-broker hostnames don’t resolve to the Gateway, or the broker certificates don’t include them. Check your DNS records, and verify the certificate SANs:

kubectl get secret <cert-secret-name> --namespace <namespace> \
  -o jsonpath='{.data.tls\.crt}' | base64 -d | openssl x509 -noout -text | grep DNS

TLSRoutes exist but have no status, and the Gateway reports attachedRoutes: 0: Your Gateway controller isn’t watching TLSRoute at the v1 API that Redpanda uses, and its log shows a message such as TLSRoute CRD not found, skipping TLSRoute watch. Upgrade to a controller version that watches TLSRoute at v1 (for Envoy Gateway, version 1.8 or later). Restarting the controller does not help on its own. See Prerequisites.

TLSRoutes have a status.parents entry but the route is not Accepted: The route’s parentRefs doesn’t match the Gateway’s name, namespace, or listener sectionName, or your Gateway controller doesn’t support the listener’s TLS mode for TLSRoute. Termination support is optional in the Gateway API specification. See Choose a TLS mode.

Clients fail TLS certificate verification: The client is validating against the wrong CA for the Gateway’s TLS mode. With passthrough, clients must trust the CA of the broker certificates. With termination, they must trust the CA of the Gateway’s certificate.

Connection refused or routed to the wrong broker: Verify that your client sends SNI. Connections without SNI (for example, plain TCP tools like nc) cannot be routed. Test with:

openssl s_client -connect <gateway-address>:443 -servername redpanda.example.com </dev/null

Next steps

Suggested reading