jFaaS - A multi-FaaS toolkit to facilitate development of portable Java applications

General overview

jFaaS is a Java toolkit that can be imported in a Java application to allow a portable invocation of serverless functions on all well-known FaaS providers by abstracting all their individual APIs.

jFaaS offers a single interface requires function location (e.g., ARN on AWS) and the function input. For invocation with authentication, jFaaS requires credentials in the form presented bellow.

Supported portable invocations

Invocations are supported on all well-known FaaS providers with or without authentication:

• With authentication

  • AWS Lambda (LambdaInvoker.java)
  • IBM Cloud Functions (OpenWhiskInvoker.java)
  • Google Cloud Functions (GoogleFunctionInvoker.java)
  • Microsoft Azure Functions (AzureInvoker.java)

• Without authentication (HTTPGETInvoker.java) - all FaaS providers that support function invocations with HTTP GET requests

  • AWS Lambda
  • IBM Cloud Functions
  • Google Cloud Functions
  • Microsoft Azure Functions
  • Alibaba
  • etc

Test phase - invoking tasks into a VM (VMInvoker.java)

• Amazon EC2
• Azure VMs

Build

gradle shadowJar

The generated jFaaS-all.jar file can be found in the build/libs/ folder.

Example(s)

Structure credentials.proporties, which should be placed in the same folder as the jFaaS-all.jar:

aws_access_key=
aws_secret_key=
aws_session_token=              // (needed for AWS Educate)
ibm_api_key=
google_sa_key={\
 "type": "",\
 "project_id": "",\
 "private_key_id": "",\
 "private_key": "-----BEGIN PRIVATE KEY-----\\n ... \\n-----END PRIVATE KEY-----\\n",\
 "client_email": "",\
 "client_id": "",\
 "auth_uri": "",\
 "token_uri": "",\
 "auth_provider_x509_cert_url": "",\
 "client_x509_cert_url": ""\
}
azure_key=

Gateway (preferrable)

// Create instance of Gateway
Gateway gateway = new Gateway("path/to/credentials.properties");

// Set input parameters for cloud function
Map<String, Object> input = new HashMap<>();
input.put("input", "value");

// Invoke functions
PairResult<String, Long> resultLambda = null;
PairResult<String, Long> resultOpenWhisk = null;
try {
    resultLambda = gateway.invokeFunction("arn:aws:lambda:eu-central-1:xxxxxxxxxxx:function:functionName", input);
    resultOpenWhisk = gateway.invokeFunction("https://jp-tok.functions.cloud.ibm.com/api/v1/web/xxxxxxxxxxx/default/functionName", input);
} catch (IOException e) {
    e.printStackTrace();
}

// Continue with result variables (output of function and Round Trip Time)
String output = resultLambda.getResult();
Long RTT = resultLambda.getRTT();
...

HTTPGETInvoker

// Create instance of HTTPGETInvoker
FaaSInvoker faaSInvoker = new HTTPGETInvoker();

// Set input parameters for cloud function
Map<String, Object> input = new HashMap<>();
input.put("input", "value");

// Invoke function
PairResult<String, Long> result;
try {
    result = faaSInvoker.invokeFunction("https://jp-tok.functions.cloud.ibm.com/api/v1/web/xxxxxxxxxxx/default/functionName.json", input);
} catch (IOException e) {
    e.printStackTrace();
}

// Continue with result variable (output of function and Round Trip Time)
String output = resultLambda.getResult();
Long RTT = resultLambda.getRTT();
... 

Contributions

This project resulted as a part of several bachelor theses at department of computer science, University of Innsbruck, supervised by Dr. Sashko Ristov (sashko@dps.uibk.ac.at):

• "G2GA: Portable execution of workflows in Google Cloud Functions across multiple FaaS platforms", Anna Kapeller and Felix Petschko, SS2021 (Google and Azure function invokers)
• "Running workflow applications across multiple cloud providers", Marina Aichinger, SS2020 (AWS and Azure VM invoker)
• "Multi-provider enactment engine (EE) for serverless workflow applications", Jakob Nöckl, Markus Moosbrugger, SS2019. Among top three theses for 2019 at the institute of computer science. (AWS and IBM function invokers)

Support

If you need any additional information, please do not hesitate to contact sashko@dps.uibk.ac.at.