Functions

DroneDeploy Functions is your tool for writing, running, and deploying backend code functionality.

DroneDeploy Functions uses serverless architecture running on the DroneDeploy Platform. You can write Node.js code to build out custom backend functionality and hook into things like Datastore and Triggers seamlessly. No need to worry about hosting since this is all handled by DroneDeploy.

Runtime

DroneDeploy Functions currently run on the Node.js 16 runtime.

Writing a Function

Learn more about the full file structure under the App Development section.

You can see an example function in our IFTTT sample app.

A DroneDeploy Function has the following files:

├── functions
│   └── webhook
│       ├── config.json
│       ├── dronedeploy.js
│       ├── handler.js
│       └── package.json

handler.js

The handler.js file is where you write your code. The following code should look familiar if you have ever written a node.js request module.

exports.helloWorld = function (req, res, ctx) {
  res.status(200).send('Hello World!');
};

req is the incoming request

res is what you use to respond to the incoming request

ctx provides you with DroneDeploy context that may be useful for App development.

• if a request comes in with a DroneDeploy scoped JWT token, you can reference the user's username with ctx.token.username.

• you can also directly access our GraphQL APIs for making an API call to DroneDeploy with ctx.graphql.query. Note that these queries are already authenticated via the JWT token included in the Function request.

• you can also directly make calls to the Datastore via a command like ctx.datastore.table('Table:5ada2d8f27b7b90001b9c40a'). You can then add and query for Datastore data like so:

const getTableData = (ctx, id) => {
  return getTableId(ctx).then((tableId) => {
    const table = ctx.datastore.table(tableId);
    return table.getRowByExternalId(id)
    .then((result) => {
      if (!result.ok) {
        console.log('getTableData bad results');
        if (couldNotFindData(result)) {
          console.log('row does not exist');
          return null;
        }
        return Promise.reject(result.errors[0]);
      }
      return result.data;
    });
  });
}

You can learn more about the ctx object from the @dronedeploy/function-wrapper README.

config.json

The .env file allows you to determine whether or not this function should be protected behind DroneDeploy JWTs. The file is not mandatory. Typically when used your file should look like this (presented with default values):

AUTH_REQUIRED=true
MOCK_TOKEN=false
CORS_HEADERS=some-cors-header,some-other-allowed-header

However, you may want to add custom CORS headers or disable auth to have an open endpoint for certain usecases like implementing OAuth.

dronedeploy.js

The dronedeploy.js file is the wrapper code for allowing DroneDeploy to handle things like auth and building function context. Your dronedeploy.js file should look almost identical to the one below. The only modification might be the handler.helloWorld(req, res, ctx) line to change which Node.js module export you would like to use.

'use strict';
const bootstrap = require('@dronedeploy/function-wrapper');
const handler = require('./handler');

exports.dronedeploy = bootstrap((ctx) => (req, res) => handler.helloWorld(req, res, ctx));

package.json

The package.json file is where you define your NPM dependencies.

It is important to have the "main" field be dronedeploy.js as that is how the platform knows which file to run.

{
  "name": "ifttt-webhook",
  "version": "0.1.0",
  "description": "",
  "main": "dronedeploy.js",
  "author": "dronedeploy",
  "license": "MIT",
  "dependencies": {
    "@dronedeploy/function-wrapper": "1.3.2",
    "dotenv": "5.0.1",
    "md5": "^2.2.1",
    "request": "2.87.0"
  },
  "devDependencies": {
    "jasmine": "3.1.0",
    "@dronedeploy/dronedeploy-cli": "1.1.1"
  }
}

In order to secure your DroneDeploy Function, you will need to use the DroneDeploy function-wrapper. The function wrapper handles authentication and authorization with DroneDeploy JWT tokens automatically.

You can install the wrapper with the following command:

    $ npm i --save @dronedeploy/function-wrapper

You will also need to make sure that your have the dronedeploy-cli installed as a development dependency to be able to deploy correctly using the CLI. If you do not already have the CLI defined as a dependency in package.json, you can install it by running the following command.

    $ npm install --save-dev @dronedeploy/dronedeploy-cli

Deploying a Function

The easiest way to deploy a DroneDeploy Function is by using the DroneDeploy CLI. You can learn more about it in the App Development section of this Documentation.

Limits

• Functions are stateless

• Maximum function timeout is 540 seconds

• Maximum memory allocation is 2048 mb