Creating a Service

You can create a Knative service by applying a YAML file or using the kn service create CLI command.

Prerequisites

To create a Knative service, you will need:

• A Kubernetes cluster with Knative Serving installed. For more information, see Installing Knative Serving.
• Optional: To use the kn service create command, you must install the kn CLI.

Procedure

Tip

The following commands create a helloworld-go sample service. You can modify these commands, including the container image URL, to deploy your own application as a Knative service.

Create a sample service:

Apply YAMLkn CLI

1. Create a YAML file using the following example:

   apiVersion: serving.knative.dev/v1
   kind: Service
   metadata:
   name: helloworld-go
   namespace: default
   spec:
   template:
   spec:
   containers:
       - image: gcr.io/knative-samples/helloworld-go
       env:
           - name: TARGET
           value: "Go Sample v1"

2. Apply the YAML file by running the command:

   kubectl apply -f <filename>.yaml

   Where <filename> is the name of the file you created in the previous step.

kn service create helloworld-go --image gcr.io/knative-samples/helloworld-go

After the service has been created, Knative performs the following tasks:

• Creates a new immutable revision for this version of the app.
• Performs network programming to create a route, ingress, service, and load balancer for your app.
• Automatically scales your pods up and down based on traffic, including to zero active pods.