Marchio-lambda-delete NPM

marchio-lambda-delete

REST DELETE from DynamoDB via Lambda

Installation

$ npm init
$ npm install marchio-lambda-delete --save

Lambda Setup

References

Steps

Create Test Role

Browse to: https://console.aws.amazon.com/iam/
Click: Roles (from the left column)
Click: Create new role
Step 1: Select role type
Expand Section: AWS Service Role
For AWS Lambda, click: Select
Step 2 is automatically skipped
Step 3: Attach policy
Select both AmazonDynamoDB* policies
Click: Next Step
Create a name for the role (like lambda-db-delete)
Click: Create role

Create Lambda Function

Browse to: https://console.aws.amazon.com/lambda
Click: Create a Lambda Function
Select: Blank Function
Click: Next
Name: marchio-delete
Description: Marchio service
Runtime: Node.js 4.3
Set the Role
Role: Choose and existing role
Existing role: service-role/(name of role you created earlier)
Click: Next
Click: Create Function

Setup API Gateway

Browse to: https://console.aws.amazon.com/apigateway
Click: Create API
Select: New API
API name: marchio-delete
Description: Marchio service
Click: Create API
Click on the slash (/)
Drop down: Actions
Select: Create Resource
Check: Configure as proxy resource
(Optionally enabled CORS)
Click: Create Resource
For Integration type select: Lambda Function Proxy
Lambda Region: For example: us-east-1
Lambda Function: marchio-delete
Click: Save
Add Permission to Lambda Function: OK
Drop down: Actions
Select: Deploy API
Define a new stage (call it "test")
Click: Deploy
Save the Invoke URL

Create DynamoDB Table

If you've already setup a demo for marchio-lambda-post then you may have this table already. If not, create it and load it with a few test records.

Browse to: https://console.aws.amazon.com/dynamodb/
Click: Create Table
Table name: mldb
Primary key: eid
The type should be the default (string)
Click: Create
After some churning, click the Capacity tab
Set the Read / Write capacity units to 1 to save money while testing
Click: Save

Example and Deploy

See the deployment example located in the repo under:

examples/deploy

It contains a deployment script and an example lambda source file.

Install the dependencies by running:

$ npm install

To run the script you must first make it runnable:

$ chmod +x deploy-lambda.sh

To test:

Deploy the API via API Gateway
Create an environment variable called AWS_HOST_MARCHIO_DELETE which is set to the invocation url
Test the deployment using curl (substitute a valid eid value):

$ curl -i -X DELETE -H "Accept: applications/json" \
  $AWS_HOST_MARCHIO_DELETE/test/marchio-delete/110ec58a-a0f2-4ac4-8393-c866d813b8d1

The response should contain a 204 status code.

Partition / Sort Tables

For DynamoDB tables where you have a partition and a sort key append the sort value to the URL:

$ curl -i -X DELETE -H "Accept: applications/json" \
  $AWS_HOST_MARCHIO_DELETE_SORT/test/marchio-delete/mldb-sort/110ec58a-a0f2-4ac4-8393-c866d813b8d1/record-sort-key

Modules

marchio-lambda-delete

Module

marchio-lambda-delete-factory

Factory module

marchio-lambda-delete-factory.create(spec) ⇒ Promise

Factory method It takes one spec parameter that must be an object with named parameters

Kind: static method of marchio-lambda-delete-factory
Returns: Promise - that resolves to {module:marchio-lambda-delete}

Param	Type	Description
spec	Object	Named parameters object
spec.event	Object	Lambda event
spec.context	Object	Lambda context
spec.callback	function	Lambda callback
spec.model	Object	Table model

Example (Usage example)

// Lambda root file
"use strict";

var mlFactory = require('marcio-lambda-delete'); 

exports.handler = function(event, context, callback) {

    var model = {
        name: 'mldb',   // must match DynamoDB table name
        partition: 'eid', // primary partition key - cannot be reserved word (like uuid)
        // sort: 'gid',  // primary sort key
        fields: {
            eid:      { type: String },  // primary partition key
            // gid:      { type: String },  // primary sort key           
            email:    { type: String, required: true },
            status:   { type: String, required: true, default: "NEW" },
            // Password will be (fake) hashed by filter before being saved
            password: { type: String, select: false },  // select: false, exclude from query results
        }
    };

    mlFactory.create({ 
        event: event, 
        context: context,
        callback: callback,
        model: model
    })
    .catch(function(err) {
        callback(err);
    });
 };

Testing

To test, go to the root folder and type (sans $):

$ npm test

Repo(s)

Contributing

In lieu of a formal style guide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code.