push notifications

[edzillion]

Amazon offers a push notif service that should do the job. Some thinking about what users should be notified needs to be done before we can implement this fully

related to: CirclesUBI/circles-api#32

[edzillion]

Looked into the various options and settled on Amazon SNS; which gives us fairly straightforward implementation of push messages to android / ios.

SNS requires that each client be registered with a deviceId. For the moment I am using Expo.Constants.deviceId but this will be changed to a native implementation later. I originally built a very basic express server to test this device registration, but then realised it could be done in the confirmUser lambda with a bit of work.

• infrastructure-provisioning/circles-sns repo holds the terraform build for the SNS resources, as well as a test server (which I will remove now).
• circles-sns repo holds the code for this test server. This is now redundant as I have moved things to lambda but could be used for an sns microservice in future if that was the route we take.
• circles-lambdas contains the confirmUser() function which calls the sns function to register a device endpoint (so that we can message this user later):

var sns = new AWS.SNS({apiVersion: '2010-03-31'})
exports.handler = (event, context, callback) => {
  var snsParams = {
    PlatformApplicationArn: process.env.ANDROID_ARN,
    Token: event.request.userAttributes.deviceId
  }

  sns.createPlatformEndpoint(snsParams, function (err, data) {
    if (err) console.log(err, err.stack)
    else console.log(data)
  })
}

• I have added a custom field to the Cognito User Pool called 'deviceId' which is pulled out of the request and used to set the Token param.

This is as far as I have gotten, obviously we need a db table to associate userNames with these endpoints.

[edzillion]

The previous sns registration stuff was moved from the FE to the circles-api. We need to extend this somewhat and need a full notification api to simplify messaging to the various platforms etc, and on the frontend we will need a way to interpret these messages.

we could either go for this popular package https://github.com/zo0r/react-native-push-notification

tutorial here: https://medium.com/@thexap/show-push-notifications-on-react-native-app-a613a5a2c159

Or we could use amplify (perhaps with a redux saga to queue events etc):

https://aws-amplify.github.io/docs/js/push-notifications

related to: CirclesUBI/circles-api#32