Dart OpenWhisk function templates

This repository contains OpenWhisk function templates for writing serverless functions in the Dart programming language.

Usage

  1. Make sure OpenWhisk has been deployed to your Kubernetes cluster and the OpenWhisk CLI tool has been installed. See here and here for a brief introduction on how to do this.

  2. Download the Dart function templates from this repo and enter into the main directory:

git clone https://github.com/nicklasxyz/dart_openwhisk && \
cd dart_openwhisk
  1. Add new functionality to the function that is going to be deployed and managed by OpenWhisk:

code template/function/lib/src/function_base.dart
# ... Inside this file extend or add whatever you want to below the 'handleRequest' function

Note: The files and directories in the dart_openwhisk/template directory are a part of a usual Dart project, but structured specifically for use with OpenWhisk. All new functionality should primarily be implemented as a part of the function package residing in the dart_openwhisk/template/function/ directory. Extra dependencies should be added to the respective pubspec.yaml files in the root of the template or in the template/function directory. The project can be compiled and tested locally as usual. See the forllowing README.md for more information.

  1. Build and push the function:

# Define your docker image name and function name below
export FUNC_NAME=  # For example: test-function
export IMAGE_NAME= # For example: username/test-function:latest

# Then build and push the docker image to Docker Hub:
docker build template --tag $IMAGE_NAME && docker push $IMAGE_NAME
  1. Create a package and deploy the serverless function:

wsk -i package create demo && \
wsk -i action create /guest/demo/$FUNC_NAME --docker $IMAGE_NAME --web true

# To remove function deployments run:
wsk -i action delete /guest/demo/$FUNC_NAME
  1. Wait a few seconds, then we can invoke the function by sending a request through curl:

### Retrieve function invocation URL
export FUNC_URL=$(wsk -i action get /guest/demo/$FUNC_NAME --url | tail -1)

### Example GET request
curl -k \
  -X GET $FUNC_URL; \
  echo

# If nothing was changed in the 'dart_openwhisk/template/function' 
# directory before deployment then we should just see the default response:
>> Hello from OpenWhisk & Dart!

### Example POST request:
curl -k \
  -d "{\"name\": \"Peter\", \"age\": \"42\", \"height\": \"180.5\"}" \
  -H "Content-Type: application/json" \
  -X POST $FUNC_URL; \
  echo

# If nothing was changed in the 'dart_openwhisk/template/function'
# directory before deployment then we should just see the default response:
>> [{"string_field":"Peter"}, {"int_field":42}, {"double_field":180.5}]

For more information on how other request methods work see the OpenWhisk API gateway docs

GitHub

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