What methods of publishing applications from…

Service Type

ClusterIP: Internal IP address accessible only within the cluster.
NodePort: Opens a port on each cluster node, traffic is redirected to Pod.
LoadBalancer: Integrates with cloud provider to create an external load balancer.

Ingress

Provides routing of HTTP/S traffic based on rules. Requires an Ingress controller (e.g., Nginx Ingress).

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
spec:
  rules:
  - host: myapp.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: my-service
            port:
              number: 80

Ingress Gateway (Service Mesh)

In a Service Mesh (e.g., Istio, Linkerd), an Ingress Gateway manages incoming traffic, including advanced routing, security policies (mTLS), and observability.

apiVersion: networking.istio.io/v1beta1
kind: Gateway
metadata:
  name: my-gateway
spec:
  selector:
    istio: ingressgateway # Uses Istio's default ingress gateway
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - myapp.example.com

ExternalName Service

Creates a CNAME record in its DNS pointing to an external FQDN. Does not redirect traffic.

apiVersion: v1
kind: Service
metadata:
  name: my-ext-service
spec:
  type: ExternalName
  externalName: api.external.com

HostNetwork

Allows a Pod to use the node's network namespace. Usually not recommended for security and isolation reasons.

Using Third-Party Load Balancers and Reverse Proxies

Mechanism: Traffic first hits an external load balancer (HAProxy, Nginx Outside Kubernetes) or CDN, which then redirects it to NodePort or LoadBalancer Service in the cluster.
Advantages: Improved caching, WAF, more granular traffic control to the cluster.

Publishing via VPN

For accessing internal Kubernetes services from outside, but in a controlled environment.

Summary table of publishing methods:

Method	Level	Purpose	Advantages	Disadvantages
`Service Type: ClusterIP`	Internal	Interaction within the cluster	Simplicity, security (internal)	Not accessible from outside
`Service Type: NodePort`	Node	Access at the node level	Simplicity, clarity	Uses node ports, not scalable
`Service Type: LoadBalancer`	Cloud	External access via cloud LB	Auto-scaling, cloud integration	Cloud LB costs, provider dependency
`Ingress`	L7 (HTTP/S)	Routing of HTTP/S traffic	Routing flexibility, centralized management	Requires Ingress Controller
`Ingress Gateway`	L7 (Service Mesh)	Advanced traffic management (mTLS, A/B)	Rich Service Mesh features	Requires Service Mesh deployment
`ExternalName Service`	DNS	Points to an external FQDN	Easy external service pointing	Does not redirect traffic
`HostNetwork`	Node network	Uses node's network namespace	Direct network access to the node	Security risks, poor isolation
`Third-Party LB/RP`	L4/L7 (External)	Advanced cluster capabilities	WAF, CDN, finer control	Additional infrastructure needed
`VPN`	Network	Controlled external access	Security (inside VPN)	VPN setup required

What methods of publishing applications from Kubernetes do you know?