Serverless Framework and OpenWhisk — Plugin Update (v0.6)

Published in

Apache OpenWhisk

3 min readApr 12, 2017

The Serverless Framework now has even better support for the OpenWhisk platform!

There is a new version of the OpenWhisk provider plugin for The Serverless Framework. This release adds support for non-Node.js runtimes, including Python, Swift, Docker and Binaries.

The update also includes improved error messages for application errors, invoke local support for the Python runtime and showing Web Action URLs in serverless info.

Use the following command to upgrade the provider plugin to the latest version (0.6).

npm update -g serverless-openwhisk

Due to an outstanding issue with provider plugins, the OpenWhisk provider must be installed as a global module.

Here are the new features supported in the latest release….

Python Support

Serverless functions can be written for the Python 2.7 or 3.6 runtimes.

Setting the runtime parameter in serverless.yaml will control the environment used.

service: python-serviceprovider:
  name: openwhisk
  runtime: python // defaults to python 2.7functions:
  greeting:
    handler: handler.endpoint
  greeting_py3:
    handler: handler.endpoint
    runtime: python:3plugins:
  - serverless-openwhisk

Python functions are invoked with a Dictionary containing event parameters. Functions must return a Dictionary with response values.

def endpoint(params):
    name = params.get("name", "stranger")
    greeting = "Hello " + name + "!"
    print(greeting)
    return {"greeting": greeting}

The invoke local plugin has also been extended to support Python functions.

Swift Support

Serverless functions can be written for the Swift 3 runtime.

service: swift-serviceprovider:
  name: openwhisk
  runtime: swiftfunctions:
  greeting:
    handler: handler.mainplugins:
  - serverless-openwhisk

Swift functions are invoked with a Dictionary containing event parameters. Functions must return a Dictionary with response values.

func main(args: [String:Any]) -> [String:Any] {
    let formatter = DateFormatter()
    formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
    let now = formatter.string(from: Date())    if let name = args["name"] as? String {
        return [ "greeting" : "Hello \(name)! The time is \(now)" ]
    } else {
        return [ "greeting" : "Hello stranger! The time is \(now)" ]
    }
}

Binaries Support

OpenWhisk supports executing a compiled binary for the serverless function. The binary must be compiled for the correct platform architecture.

OpenWhisk executes the binary file for each request. Event parameters are streamed to stdio as a JSON object string.

The handler must write a JSON object string with the response parameters to stdout before exiting.

In the serverless.yaml file, the handler property is used to denote the binary file to upload.

functions:
  my_function:
    handler: bin_file
    runtime: binary

Docker Support

OpenWhisk supports custom runtimes using public images on Docker Hub. These images are expected to support the platform API used to instantiate and invoke serverless functions.

All necessary files for execution must be provided within the image. Local source files will not be uploaded to the runtime environment.

In the serverless.yaml file, the handler property is used to denote the image label.

functions:
  my_function:
    handler: repo/image_name
    runtime: docker

Web Action URLs

This serverless info command will now show URLs for Web Actions.

$ serverless info
Service Information
platform: openwhisk.ng.bluemix.net
namespace: _
service: swift-serviceactions:
swift-service-dev-pingendpoints (web actions):
https://openwhisk.ng.bluemix.net/api/v1/web/james.thomas@uk.ibm.com_dev/default/swift-service-dev-ping