Types of services in Kubernetes

Category : Kubernetes | Sub Category : Kubernetes With Java | By Prasad Bonam Last updated: 2024-01-30 10:16:56 Viewed : 162

In Kubernetes, services are used to expose applications and services to other components within the cluster or external systems. There are several types of services in Kubernetes, each serving a different purpose. Here are the common service types:

1. ClusterIP:

   • Exposes the service on a cluster-internal IP address.
   • The service is accessible only within the cluster.

   yamlCopy code
   kind: Service
   apiVersion: v1
   metadata:
     name: my-service
   spec:
     selector:
       app: my-app
     ports:
       - protocol: TCP
         port: 80
         targetPort: 8080
     type: ClusterIP
   

2. NodePort:

   • Exposes the service on a static port on each nodes IP.
   • Makes the service accessible from outside the cluster using the nodes IP and the static port.

   yamlCopy code
   kind: Service
   apiVersion: v1
   metadata:
     name: my-service
   spec:
     selector:
       app: my-app
     ports:
       - protocol: TCP
         port: 80
         targetPort: 8080
     type: NodePort
   

3. LoadBalancer:

   • Exposes the service externally using a cloud providers load balancer.
   • Automatically assigns an external IP to the service.

   yamlCopy code
   kind: Service
   apiVersion: v1
   metadata:
     name: my-service
   spec:
     selector:
       app: my-app
     ports:
       - protocol: TCP
         port: 80
         targetPort: 8080
     type: LoadBalancer
   

4. ExternalName:

   • Maps the service to the contents of the externalName field (e.g., a DNS name).
   • It does not provide load balancing or other features typical of other service types.

   yamlCopy code
   kind: Service
   apiVersion: v1
   metadata:
     name: my-service
   spec:
     type: ExternalName
     externalName: my.external.service
   

5. Headless:

   • Creates a service without a cluster-internal IP.
   • Useful for services that do not require load balancing, and you want to interact directly with the individual pods.

   yamlCopy code
   kind: Service
   apiVersion: v1
   metadata:
     name: my-service
   spec:
     selector:
       app: my-app
     clusterIP: None
   

These service types provide flexibility in exposing and accessing applications within a Kubernetes cluster. The appropriate type depends on the specific requirements and use case of your application.