Kubeless Serverless Plugin

This plugin brings Kubeless support within the Serverless Framework.

Kubeless is a Kubernetes-native Serverless solution.

Pre requisites

Make sure you have a kubernetes endpoint running and kubeless installed. You can find the installation intructions here.

Once you have Kubeless running in your cluster you can install serverless

$ npm install serverless -g

Try out the example

Clone this repo and check the example function

$ git clone https://github.com/serverless/serverless-kubeless
$ cd serverless-kubeless/examples/get-python
$ cat serverless.yml
service: hello
provider:
  name: kubeless
  runtime: python2.7
plugins:
  - serverless-kubeless
functions:
  hello:
    description: 'Hello function'
    handler: handler.hello

Download dependencies

$ npm install

Deploy function.

$ serverless deploy
Serverless: Packaging service...
Serverless: Excluding development dependencies...
Serverless: Deploying function hello...
Serverless: Function hello successfully deployed

The function will be deployed to k8s via kubeless.

$ kubectl get function
NAME      AGE
hello     50s
$ kubectl get pod
NAME                     READY     STATUS    RESTARTS   AGE
hello-1815473417-1ttt7   1/1       Running   0          1m

Now you will be able to call the function:

$ serverless invoke -f hello -l
Serverless: Calling function: hello...
--------------------------------------------------------------------
hello world

You can also check the logs for the function:

$ serverless logs -f hello
172.17.0.1 - - [12/Jul/2017:09:47:18 +0000] "GET /healthz HTTP/1.1" 200 2 "" "Go-http-client/1.1" 0/118
172.17.0.1 - - [12/Jul/2017:09:47:21 +0000] "GET /healthz HTTP/1.1" 200 2 "" "Go-http-client/1.1" 0/93
172.17.0.1 - - [12/Jul/2017:09:47:24 +0000] "GET /healthz HTTP/1.1" 200 2 "" "Go-http-client/1.1" 0/108
172.17.0.1 - - [12/Jul/2017:09:47:25 +0000] "GET / HTTP/1.1" 200 11 "" "" 0/316

Or you can obtain the function information:

$ serverless info
Service Information "hello"
Cluster IP:  10.0.0.51
Type:  ClusterIP
Ports:
  Name:  http-function-port
  Protocol:  TCP
  Port:  8080
  Target Port:  8080
Function Info
Description: Hello function
Handler:  handler.hello
Runtime:  python2.7
Trigger: HTTP
Dependencies:

You can access the function through its HTTP interface as well using kubectl proxy and accessing:

$ curl http://127.0.0.1:8001/api/v1/namespaces/default/services/hello/proxy/
hello world

If you have a change in your function and you want to redeploy it you can run:

$ serverless deploy function -f hello
Serverless: Redeploying hello...
Serverless: Function hello successfully deployed

Finally you can remove the function.

$ serverless remove
Serverless: Removing function: hello...
Serverless: Function hello successfully deleted

Kubernetes secrets

Kubernetes secret objects let you store and manage sensitive information, such as passwords, OAuth tokens, and ssh keys. Putting this information in a secret is safer and more flexible than putting it verbatim in a Pod definition or in a container image. To use secrets follow the next steps:

  1. Create a K8s secret: kubectl create secret generic secret-file --from-file=secret.txt -n namespace-name

  2. Add the secret key into the provider definition in the serverless.yml file below the secrets key. You can specify an array of secrets and they will be mounted at root level in the pod file system using the path /<secret-name>:

...
functions:
  my-handler:
    secrets:
      - secret-file
    ...
  1. Now inside your pod, you will be able to access the route /secret-file/secret.txt.