DAF

Dependency-aware FaaSifier

DAF lets you outsource parts of a NodeJS app to FaaS

In addition to existing tools, it supports:

• Dependencies (install)
• Importing other files and functions (require)

Install

npm i -g daf # install globally

Usage

1. Add annotations in your Monolith code:

// l     
var a = 1;
// lend 

The enclosed code will be packaged into a FaaS function.

2. Run DAF via Editor Extension:

Search for DAF-VSCode on the VSCode Marketplace.

3. Output

The tool creates an equivalent Lambda function of that section in [--output]/lambdas/[name]:

└── lambdas
    └── 28723n2398jfs9f87239uhfe9
        ├── index.js
        └── package.json 

You can zip this folder and upload it directly to Amazon Lambda. One file can have multiple // l ... // lend sections, that can be converted separately.

Annotation syntax

//l can be followed by any combination of these space-separated directives.

name

You can give your Lambda a name to better keep track of it:

// l name(mylamb)
 var a = 1
// lend

└── lambdas
    └── mylamb
       └── ....
    

require

Your code might rely on functions from other files. You can declare that using require():

// l require(./foo.js as foo)
foo()
// lend

A portable version of foo.js is then included in the deployment package, and it is added to the scope inside the Lambda.

└── lambdas
    └── myfunc
       └── foo.js  // <---
       └── ...

If foo in turn depends on other functions or dependencies, they are bundled as well (recursively) using webpack.

install

Your code might depend on NPM packages. You can specify them with install(). They will be included in your deployment package.

// l install(opencv2)
....
// lend

You probably want to import it as well:

// l install(opencv2) require(opencv2 as opencv2)
   opencv2.detectFaces(...)
// lend

return

Your monolith code may have no return statement. To receive something back from the lambda, use return()

// l return(a)  
  var a = 1
  var b = 2
// lend

---

Useful hints

Multiple parameters

With most // l expressions, you can provide a comma-separated list too:

// l install(lodash, rollup, express)
...