GSoC 2018 Proposal
Project: Fineract SMS/Email Notification Microservice.
Applicant: Ebenezer Kwesi Akyen Graham
Abstract
This project is a new feature request for the Apache Fineract CN. The SMS/Email Notifications service would be a microservice developed on Apache Fineract CN to enable MFI members to get notified on events occurring on their accounts.
There are arrays of events occurring in other microservices therefore there is a need to streamline these events and notify MFI members of significant events. This will impact the KYC of the organisation and the user experience.
This problem has led to the need for a microservice such as this one to be developed to enable MFI staff members to select notifications which the member chooses during account creation.
Project Goals
Develop a SMS/Email notification mircroservice
Incorporate the microservice into a demo-server
Incorporate the Notification user interface into the fims-web-app
Interface for microservice configuration
Interface to select frequency for members
Interface to subscribe members to specific events
Proposed Solution
When an event occurs, the system knows the subscribers to notify and now the notification itself has to be generated. An event listener listening to the rest API controller event, will then create an instance of the corresponding mircroservice interact with it.
NB: each mircroservice will have a corresponding listener listening to it event emitters. For instance, AccountingListener, OrganisationListener etc
The notification service will start by creating a notification object for the event, the notification object will be persisted in to the database and later added to a notification queue for processing.
The notifications are then mapped to the list of members who have to receive them (for instance a new client created event can send out a notification to the customer (customer), the manager of the office (staff) and anyone who needs to know of an new client account) and at this stage notification which do not have to be sent are discarded based the subscriber’s priority declarations.
The notification mappings are then persisted into the database and then queued into a notification-subscriber queue for processing
The notification-subscriber queue is taken and transmission begins.
To personalise the message, a subscriber’s prefered language and communication stated during account creation is used to localize and choose the gateway to use. For instance if a customer indicates only SMS is sent through to their mobile and not the email. If both is indicated both SMS and email is used
A member who selected a communication channel during account creation has indicated consent to receive notifications hence we have to determine how often they will receive emails to avoid spamming them.
To determine how frequent a member gets a notification, the subscribers predefine notifications they would like to receive based on three priority categories (ie during account creation a user chooses a topic and assigns High, Medium and Low priority to it ). The system will also predefined default topics which have to go out eg: (Client created, Loan created, Account Created etc).
The messages are now formatted using a template associated to a topic.
The prepared messages will be passed to the application containing email gateway such as google’s SMTP server or Twilio SMS to be transmitted. I propose that the system allows multiple configurations to accommodate cases where the application supports multiple organisations who use different services.
Subsystems Breakdown
EventListener
An event listener will listen for EventEmitters generated. For instance for a new client creation the NotificationEventListener will capture the event emittered and generate the notification content
NotificationEventListener
Has microservice instance
Has a JmsListener to listen to emitted event
Has an SMSGateway/EmailGateway Object
Creates a NotificationMapper
Creates a recipient and their notification
Localize the message using subscriber preference
Sends the email or SMS
Domain
This package will define the class for the entities in the problem domain.
Notification
States the Recipient
states the action
states the content
NotificationMapper
Takes topic mapping and map notifications to subscribers
NotificationMapperRepository
Accumulate NotificationMappings
Configuration
This will be used to configure the behaviour of the system. This will be used to help scale the transmission of notifications in a day where more notifications are going out. (for instance an organisation with multiple gateways can scale in high
NotificationConfiguration
Has SMSConfiguration
Has EmailConfiguration
SMSConfiguration
Defines accountSID
Defines auth Id
EmailConfiguration
Defines and sets mail service host
Defines and sets mail service ports
Defines and sets authentication credentials
SMSService
Use the Twilio SMS service and google SMTP Server
Senders number
Retrieves organisation’s sms API configuration
Message content
EmailService
recipient addresses
Sender’s address
Authenticate email gateway
Mail content
This component will use the template component to form the message format. The template will abstract the various message formats. I believe using Apache Velocity to prepare default themes and allow the user to generate custom templates woube be a good consideration. Also, given that Fineract CN and Velocity [ http://velocity.apache.org/ ] share the same license it will be easier to use them
Template
SMS templates
Email Templates
Web Interface
An interface to configure SMS and email frequency
An interface to configure organisation(s) SMS API
An interface to configure organisation(s) Email Gateway
Database Structure
Entity 1: Subscriber
Id
communication_preference
language_preference
high_priorities
medium_priorities
low priorities
Entity 2: SMSConfigurations
Id
organisation
auth_token
accountid
option
Entity 3: EmailConfigurations
Id
organisation
auth_token
auth_secret
port
host
option