cdktf-factory

A functional wrapper for constructs & cdktf.

Usage

npm i cdktf-factory

Implementation

Example - NPM Deployment Package

import * as Path from "path";

import { Stack, Asset, Output, Reader } from "cdktf-factory";

const Name = "files";
const Construct = Stack( Name );

const assets = new Asset( Construct, "node-modules", {
    path: "./node_modules",
    type: 1
} );

new Output( Construct, "hash", {
    value: assets.assetHash
} );

const files = Object.create( {} );
Reader.read( assets.fileName ).forEach( (descriptor) => {
    const relative = Path.relative( process.cwd(), descriptor.path );
    if ( descriptor.properties.file ) files[ relative ] = {
        path: relative,
        name: descriptor.name
    };
} );

new Output( Construct, "dependencies", {
    value: JSON.stringify( files, null, 4 )
} );

Construct.source.synth();

Example - Docker

import { Stack } from "cdktf-factory";

import { Container, Image, DockerProvider } from "@cdktf/provider-docker";

const Construct = Stack("example");

new DockerProvider(Construct, "docker-provider", {});

const image = new Image(Construct, "nginx-image", {
    name: "nginx:latest",
    keepLocally: false,
});

new Container(Construct, "nginx-container", {
    name: "tutorial",
    image: image.latest,
    ports: [
        {
            internal: 80,
            external: 8000
        },
    ],
});

/*** npm run synth || npx cdktf@latest -- synth */

Construct.source.synth();

Design Philosophy

Using functions vs classes is essentially a religious debate. However, in the context of IaC, there are a few reasons to elect for functional, prototypal development.

Take for example a client package: example-client. The developer(s) behind example-client want the fastest, easiest means to define their infrastructure, but don't care to learn straight terraform as their package is purely typescript.

The first, perhaps most obvious benefit is the use of only a global namespace. There exists no class or Function nested namespaces.

I then remove the requirement of using both IContruct types: TerraformStack and App. At first when working with cdktf, I actually experienced some runtime errors when working with more than a single stack. I also experienced colleagues make the same mistakes.

Additionally, the ability to extend or inherit from Stack (at least easily), was removed.

The Stack wrapper should only ever be used as an interface -- e.g. the Stack wrapper is intended to be composed in context, not extended into a namespace.

Lastly, but most importantly, I want a means to provide long-term support while also ensuring of backwards compatability.

If the client can only initialize Stack via <Function> (input: string) (), and the return type always remains a IConstruct, I now have the capability to extend the cdktf-factory context as much as needed. For example, I can add default tags (not only in the context of aws) that then get propagated to all downstream client packages, as well as provide special terraform backend(s) by default.