K8S Reference - Service YAML

The table below summarizes all important elements used when defining a Kubernetes Service resource.

Element	Required / Optional	Description	Example Syntax
apiVersion	Required	The API group. For Services, this is always v1.	apiVersion: v1
kind	Required	Defines the resource type.	kind: Service
metadata.name	Required	The DNS name that other applications inside the cluster will use to talk to this service.	name: my-db-service
spec.ports	Required	A list of network ports to expose. Includes the port (the Service's port) and targetPort (the Pod's actual application port).	- port: 80 targetPort: 8080
spec.selector	Optional (Recommended)	A key-value label pair used to target which Pods receive traffic. Crucial for connecting the Service to your application.	selector: app: my-database
spec.type	Optional	Controls how the Service is exposed: ClusterIP (internal only), NodePort (exposes via host ports), or LoadBalancer (cloud provider external IP). Defaults to ClusterIP.	type: ClusterIP
spec.clusterIP	Optional	Can be set to None to create a Headless Service, which is strictly required when pairing with a StatefulSet to handle direct pod addressing.	clusterIP: None

Tip: The most commonly used Service types are ClusterIP, NodePort, and LoadBalancer. For StatefulSets, remember that a Headless Service (clusterIP: None) is typically required to provide stable network identities to Pods.