FaaS Shell

CircleCI License

FaaS Shell is a shell for Serverless Function Workflow, which is a common abstraction layer on top of FaaS Infrastructures to execute multiple workflow languages across multiple clouds.

Faas Shell compiles workflow language and generate workflow DSL. Then FaaS Shell interpreter executes the workflow DSL. This architecture aims at enabling Multi Cloud Strategy which exploits the most attractive features from each provider beyond vendor agnostic solution.

Faas Shell also has REPL, which allows us to develop workflow interactively typing DSL directly into the prompt.

FaaS Shell currently supports one workflow language as the first step, and five FaaS infrastructures.

You can run your Amazon State Language workflow code created in AWS Step Functions in anywhere, and your workflow can call not only AWS Lambda but also functions in other FaaS Infrastructures.

Quick Start

  1. Create Serverless Function Workflow

    Create a Lambda State Machine by following AWS Step Functions tutorial. And save the statemachine as “hello_world_task.json”.

    Assume “hello_world_task.json” looks like below except the region “us-east-2” and the account id “410388484666”:

     {
    "Comment": "A Hello World example of the Amazon States Language using a Task state",
    "StartAt": "HelloWorld",
    "States": {
       "HelloWorld": {
          "Type": "Task",
          "Resource":"arn:aws:lambda:us-east-2:410388484666:function:hello",
          "End": true
       }
    }
 }

    The lambda function “arn:aws:lambda:us-east-2:410388484666:function:hello” is defined in Nodejs 6.10 as below:

     'use strict';

 console.log('Loading function');

 exports.handler = (event, context, callback) => {
     console.log('Received event:', JSON.stringify(event, null, 2));
     var name = event.name || 'World';
     callback(null, {payload:  'Hello, ' + name + '!'});
 };

  2. Set your AWS Access Keys to environment variables.

    How to get the AWS Access Keys is described in Managing Access Keys for Your AWS Account.

     $ export AWS_ACCESS_KEY_ID=AAAAAAAAAAAAAAAAAAAA
 $ export AWS_SECRET_ACCESS_KEY=BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB

  3. Start Faas Shell

     $ docker run -d -p 5984:5984 apache/couchdb

 $ docker run -d --net=host -v /tmp:/logs \
              -e AWS_ACCESS_KEY_ID=$AWS_ACCESS_KEY_ID \
              -e AWS_SECRET_ACCESS_KEY=$AWS_SECRET_ACCESS_KEY \
              nao16t/faasshell
    • Set the proxy environment variables if you are in private network. 
      $ export HTTP_PROXY="http://id:pw@proxy.example.com:8080"
$ export HTTPS_PROXY="https://id:pw@proxy.example.com:8433"
$ export NO_PROXY="localhost,127.0.0.1,0.0.0.0,172.17.0.1"

$ docker run -d --net=host -v /tmp:/logs \
             -e AWS_ACCESS_KEY_ID=$AWS_ACCESS_KEY_ID \
             -e AWS_SECRET_ACCESS_KEY=$AWS_SECRET_ACCESS_KEY \
             -e HTTP_PROXY=$HTTP_PROXY \
             -e HTTPS_PROXY=$HTTPS_PROXY \
             -e NO_PROXY=$NO_PROXY \
             nao16t/faasshell

  4. Execute the Serverless Function Workflow

    • Set the access information 
      $ DEMO=ec29e90c-188d-11e8-bb72-00163ec1cd01:0b82fe63b6bd450519ade02c3cb8f77ee581f25a810db28f3910e6cdd9d041bf

$ FAASSHELL_APIHOST=http://127.0.0.1:8080
    • Register “hello_world_task.json”, then DSL is generated as the value of “dsl” key. 
      $ curl -ksX PUT ${FAASSHELL_APIHOST}/statemachine/hello_world_task.json \
   -H 'Content-Type: application/json' -d @hello_world_task.json -u $DEMO
 {
   "asl": {
    "Comment":"A Hello World example of the Amazon States Language using a Task state",
    "StartAt":"HelloWorld",
    "States": {
      "HelloWorld": {
        "End":true,
        "Resource":"arn:aws:lambda:us-east-2:410388484666:function:hello",
        "Type":"Task"
      }
    }
  },
  "dsl":"fsm([task('HelloWorld',\"arn:aws:lambda:us-east-2:410388484666:function:hello\",[])])",
  "name":"hello_world_task.json",
  "namespace":"demo",
  "output":"ok"
}
    • Execute the DSL, the result is returned as the value of the output key. 
      $ curl -ksX POST ${FAASSHELL_APIHOST}/statemachine/hello_world_task.json?blocking=true \
  -H 'Content-Type: application/json' -d '{"input": {"name": "Curl"}}' -u $DEMO
 {
  "asl": {
    "Comment":"A Hello World example of the Amazon States Language using a Task state",
    "StartAt":"HelloWorld",
    "States": {
      "HelloWorld": {
        "End":true,
        "Resource":"arn:aws:lambda:us-east-2:410388484666:function:hello",
        "Type":"Task"
      }
    }
  },
  "dsl":"fsm([task('HelloWorld',\"arn:aws:lambda:us-east-2:410388484666:function:hello\",[])])",
  "input": {"name":"Curl"},
  "name":"hello_world_task.json",
  "namespace":"demo",
  "output": {"payload":"Hello, Curl!"}
}

Getting Started

Quick Start showed just AWS Lambda case. Other FaaS provider cases are covered by Getting started.

Getting started also explains how to deploy function making use of each provider’s CLI, how to build and deploy FaaS Shell, how to use REST API, and etc.

Samples directory contains some examples in each provider’s sub-directory based on the following State Machine Template.

Demo

Devloper’s Guide (work in progress)

Reference (work in progress)

TODO