Chapter 4. Getting started with Knative services
Knative services are Kubernetes services that a user creates to deploy a serverless application. Each Knative service is defined by a route and a configuration, contained in a .yaml file.
4.1. Creating a Knative service
To create a service, you must create the service.yaml file.
You can copy the sample below. This sample will create a sample golang application called helloworld-go and allows you to specify the image for that application.
apiVersion: serving.knative.dev/v1alpha1 1 kind: Service metadata: name: helloworld-go 2 namespace: default 3 spec: template: spec: containers: - image: gcr.io/knative-samples/helloworld-go 4 env: - name: TARGET 5 value: "Go Sample v1"
4.2. Deploying a serverless application
To deploy a serverless application, you must apply the service.yaml file.
Procedure
-
Navigate to the directory where the
service.yamlfile is contained. Deploy the application by applying the
service.yamlfile.$ oc apply --filename service.yaml
Now that service has been created and the application has been deployed, Knative will create a new immutable revision for this version of the application.
Knative will also perform network programming to create a route, ingress, service, and load balancer for your application, and will automatically scale your pods up and down based on traffic, including inactive pods.
