Kubeless

Kubeless is a Kubernetes-native serverless framework that lets you deploy small bits of code (functions) without having to worry about the underlying infrastructure.

Quickstart

kubeless manifests

• kubeless-$RELEASE.yaml is used for RBAC Kubernetes cluster.
• kubeless-non-rbac-$RELEASE.yaml is used for non-RBAC Kubernetes cluster.

The following deploying kubeless to a non-RBAC Kubernetes cluster.

$ export RELEASE=$(curl -s https://api.github.com/repos/kubeless/kubeless/releases/latest | grep tag_name | cut -d '"' -f 4)

$ kubectl create ns kubeless

$ kubectl create -f https://github.com/kubeless/kubeless/releases/download/$RELEASE/kubeless-non-rbac-$RELEASE.yaml

To verify kubeless have been deploy successfully.

$ kubectl get pods -n kubeless
NAME                                           READY     STATUS    RESTARTS   AGE
kubeless-controller-manager-67fbc78f6d-cqbjb   1/1       Running   0          20h

$ kubectl get deployment -n kubeless
NAME                          DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kubeless-controller-manager   1         1         1            1           20h

$ kubectl get customresourcedefinition
NAME                          AGE
cronjobtriggers.kubeless.io   20h
functions.kubeless.io         20h
httptriggers.kubeless.io      20h

CLI

Download and install kubeless CLI using execute:

Linux and macOS

$ export OS=$(uname -s| tr '[:upper:]' '[:lower:]')
$ curl -OL https://github.com/kubeless/kubeless/releases/download/$RELEASE/kubeless_$OS-amd64.zip && \
  unzip kubeless_$OS-amd64.zip && \
  sudo mv bundles/kubeless_$OS-amd64/kubeless /usr/local/bin/

Windows

1. Download the latest release from the releases page.
2. Extract the content and add the kubeless binary to the system PATH.

Runtimes

You can see the list of supported runtimes by executing:

$ kubeless get-server-config
INFO[0000] Current Server Config:
INFO[0000] Supported Runtimes are: python2.7, python3.4, python3.6, nodejs6, nodejs8, nodejs_distroless8, ruby2.4, php7.2, go1.10, dotnetcore2.0, java1.8, ballerina0.980.0, jvm1.8

Sample function

Let's create the following node.js sample nodejs-test.js

module.exports.handler = (event,context) => {
      console.log(event);
      let greeting = `hello, ${event.data}!`;
      return JSON.stringify(greeting);
}

and deploy function with:

$ kubeless function deploy hellojs \
--runtime nodejs8 \
--handler hello.handler \
--from-file hello.js
INFO[0000] Deploying function...
INFO[0000] Function hellojs submitted for deployment
INFO[0000] Check the deployment status executing 'kubeless function ls hellojs'

Check the function creation status:

$ kubeless function ls
NAME    NAMESPACE       HANDLER         RUNTIME DEPENDENCIES    STATUS
hellojs default         hello.handler   nodejs8                 1/1 READY

Call the function with:

$ kubeless function call hellojs --data 'John'
"hello, John!"

Or you can curl directly with kubectl proxyusing an apiserver proxy URL. For example:

$ kubectl proxy &

$ curl -L --data "Peter" \
  localhost:8001/api/v1/namespaces/default/services/hellojs:http-function-port/proxy/

Cleanup

Finally, let's cleanup everything.

$ kubectl delete ns kubeless
namespace "kubeless" deleted

$ kubectl delete customresourcedefinition --all
customresourcedefinition.apiextensions.k8s.io "cronjobtriggers.kubeless.io" deleted
customresourcedefinition.apiextensions.k8s.io "functions.kubeless.io" deleted
customresourcedefinition.apiextensions.k8s.io "httptriggers.kubeless.io" deleted