Request Buffering

Convert the NGINX proxy-body-size annotation to a kgateway TrafficPolicy buffer limit.

Managing the maximum allowed request size is a basic security requirement. NGINX uses the proxy-body-size annotation (equivalent to client_max_body_size). In kgateway, this is configured via the buffer field in a TrafficPolicy.

Before: Ingress with Max Body Size

Configuration for an Ingress that allows uploads up to 20MB:

cat <<'EOF' > upload-ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: upload-demo
  annotations:
    nginx.ingress.kubernetes.io/proxy-body-size: "20m"
spec:
  ingressClassName: nginx
  rules:
  - host: upload.example.com
    http:
      paths:
      - backend:
          service:
            name: upload-svc
            port:
              number: 8080
        path: /
        pathType: Prefix
EOF

Convert

ingress2gateway print --providers=ingress-nginx --emitter=kgateway \
  --input-file upload-ingress.yaml > upload-kgateway.yaml

After: TrafficPolicy with Buffer

The TrafficPolicy enforces the body size limit. buffer.maxRequestSize accepts a Kubernetes Quantity string.

Note

NGINX’s m suffix uses binary multipliers (1024 × 1024), so proxy-body-size: 20m is identical to the Quantity 20Mi. If you copied a value with a decimal suffix (20M), keep in mind it is ~5% smaller (20 × 10^6 bytes).

apiVersion: gateway.kgateway.dev/v1alpha1
kind: TrafficPolicy
metadata:
  name: buffering-policy
spec:
  targetRefs:
  - group: gateway.networking.k8s.io
    kind: HTTPRoute
    name: upload-demo-upload-example-com
  buffer:
    maxRequestSize: "20Mi"

Apply and verify

kubectl apply -f upload-kgateway.yaml
kubectl get trafficpolicies

URL Rewriting Traffic Mirroring

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