Add plugin system

[erxclau]

Motivation

For fetching or for deployment. There are a wide number of options for data sources and deployment platforms to sync with. However, not all of these strategies should be included in sink by default. Create a plugin system to allow for a greater number of potential options, without bloating the core library.

Fetching and deployment are fairly open entry points but I can imagine lifecycle entries such as pre- or post- fetch or deployment. For example, it may be useful to send a message to a Slack channel whenever sometimes deploys to AWS.

Examples

// sink.config.js

import notion from "@michigandaily/sink-plugin-notion";
import firebase from "@michigandaily/sink-plugin-firebase";

export default {
    fetch: [
        {
            "type": "notion",
            "id": "000000000",
            "auth": "./credentials.json"
        }
    ],
    deployment: {
        project: "",
        path: ""
    },
    plugins: [notion(), firebase()]
}

Fetch plugins should be integrated into sink-fetch.js, and run through yarn sink fetch <plugin-name>. This will require adding an optional argument to the fetch command.

// notion plugin
export default function notionPlugin() {
    return {
        name: "notion",
        fetch: (details) {
                 console.log(details.id, details.auth);
        }
    }
}

Deployment plugins should be integrated into sink-deploy.js, and run through yarn sink deploy <deployment-strategy>.

// firebase plugin
export default function firebasePlugin() {
     return {
         name: "firebase",
         fetch: () {
         },
         deploy: () {
         }
     } 
}