Quick .NET 6.0 Action

A .NET action is a .NET class library with a method called Main or MainAsync that has the exact signature as follows:

Synchronous:

public Newtonsoft.Json.Linq.JObject Main(Newtonsoft.Json.Linq.JObject);

Asynchronous:

public async System.Threading.Tasks.Task<Newtonsoft.Json.Linq.JObject> MainAsync(Newtonsoft.Json.Linq.JObject);

In order to compile, test and archive .NET projects, you must have the .NET SDK installed locally and ensure that the dotnet executable is included in the PATH environment variable.

For example, create a C# project called Apache.OpenWhisk.Example.Dotnet:

dotnet new classlib -n Apache.OpenWhisk.Example.Dotnet -lang C# -f netstandard2.1
cd Apache.OpenWhisk.Example.Dotnet

Install the Newtonsoft.Json NuGet package as follows:

dotnet add package Newtonsoft.Json -v 13.0.1

Now create a file called Hello.cs with the following content:

Synchronous example:

using System;
using Newtonsoft.Json.Linq;

namespace Apache.OpenWhisk.Example.Dotnet
{
    public class Hello
    {
        public JObject Main(JObject args)
        {
            string name = "stranger";
            if (args.ContainsKey("name")) {
                name = args["name"].ToString();
            }
            JObject message = new JObject();
            message.Add("greeting", new JValue($"Hello, {name}!"));
            return (message);
        }
    }
}

Asynchronous example:

using System;
using Newtonsoft.Json.Linq;
using System.Threading.Tasks;

namespace Apache.OpenWhisk.Example.Dotnet
{
    public class Hello
    {
        public async Task<JObject> MainAsync(JObject args)
        {
            await Task.Delay(10); // Just do a delay to have an async/await process occur.
            string name = "stranger";
            if (args.ContainsKey("name")) {
                name = args["name"].ToString();
            }
            JObject message = new JObject();
            message.Add("greeting", new JValue($"Hello, {name}!"));
            return (message);
        }
    }
}

Publish the project as follows:

dotnet publish -c Release -o out

Zip the published files as follows:

cd out
zip -r -0 helloDotNet.zip *

You need to specify the name of the function handler using --main argument. The value for main needs to be in the following format: {Assembly}::{Class Full Name}::{Method}, e.q.:

• Synchronous: Apache.OpenWhisk.Example.Dotnet::Apache.OpenWhisk.Example.Dotnet.Hello::Main
• Asynchronous: Apache.OpenWhisk.Example.Dotnet::Apache.OpenWhisk.Example.Dotnet.Hello::MainAsync

Create the .NET Core Action

To use on a deployment of OpenWhisk that contains the runtime as a kind:

Synchronous:

wsk action update helloDotNet helloDotNet.zip --main Apache.OpenWhisk.Example.Dotnet::Apache.OpenWhisk.Example.Dotnet.Hello::Main --kind dotnet:6.0

Asynchronous:

wsk action update helloDotNet helloDotNet.zip --main Apache.OpenWhisk.Example.Dotnet::Apache.OpenWhisk.Example.Dotnet.Hello::MainAsync --kind dotnet:6.0

Invoke the .NET Core Action

Action invocation is the same for .NET actions as it is for Swift and JavaScript actions:

wsk action invoke --result helloDotNet --param name World

  {
      "greeting": "Hello World!"
  }

Local Development

./gradlew core:dotnet3.1:distDocker

This will produce the image whisk/action-dotnet-v6.0

Build and Push image

docker login
./gradlew core:action-dotnet-v6.0:distDocker -PdockerImagePrefix=$prefix-user -PdockerRegistry=docker.io

Deploy OpenWhisk using ansible environment that contains the kind dotnet:6.0 Assuming you have OpenWhisk already deploy locally and OPENWHISK_HOME pointing to root directory of OpenWhisk core repository.

Set ROOTDIR to the root directory of this repository.

Redeploy OpenWhisk

cd $OPENWHISK_HOME/ansible
ANSIBLE_CMD="ansible-playbook -i ${ROOTDIR}/ansible/environments/local"
$ANSIBLE_CMD setup.yml
$ANSIBLE_CMD couchdb.yml
$ANSIBLE_CMD initdb.yml
$ANSIBLE_CMD wipe.yml
$ANSIBLE_CMD openwhisk.yml

Or you can use wskdev and create a soft link to the target ansible environment, for example:

ln -s ${ROOTDIR}/ansible/environments/local ${OPENWHISK_HOME}/ansible/environments/local-dotnet
wskdev fresh -t local-dotnet

Testing

Install dependencies from the root directory on $OPENWHISK_HOME repository

pushd $OPENWHISK_HOME
./gradlew install
popd

Using gradle to run all tests

./gradlew :tests:test

Using gradle to run some tests

./gradlew :tests:test --tests Net6_0ActionContainerTests

Using IntelliJ:

• Import project as gradle project.
• Make sure working directory is root of the project/repo

Using Container Image To Test

To use as docker action push to your own dockerhub account

docker tag whisk/action-dotnet-v6.0 $user_prefix/action-dotnet-v6.0
docker push $user_prefix/action-dotnet-v6.0

Then create the action using your the image from dockerhub

wsk action update helloDotNet helloDotNet.zip --main Apache.OpenWhisk.Example.Dotnet::Apache.OpenWhisk.Example.Dotnet.Hello::Main --docker $user_prefix/action-dotnet-v6.0

The $user_prefix is usually your dockerhub user id.

License

Apache 2.0