Email Sender Micro Service Kafka Consumer [Source Code]

Description

This package contains [Source Code] of a Email Sender Micro Service Web Application that has an administrative interface and is open for new emails as a Kafka Consumer.

Email Sender Web App

There are two ways this app could be packaged

• as a jar and executed in docker
• or as war and deployed in java servlet/web container.

The difference in the source code is in:

• The Application.java: 
  - public class Application implements AppShellConfigurator { //for jar

  - public class Application extends SpringBootServletInitializer { // for war

• in the pom.xml –

  <packaging>war</packaging> - for web app
  and

  <packaging>jar</packaging> for - micro service jar.

Package the Email Sender Micro Service as Jar – Docker Image

This is the default mode of execution.

• using Maria DB as Database
• auto-generate db scheme
• simple CRUD interface over the send mails
• work in progress unit tests
• docker file & setup. If you would like to run it outside docker – just change the configuration from
  host.docker.internal to localhost

Prerequisite so the Email Sender Micro Servic could function

• Setup your SMPT settings in MailSenderApplication

JavaMailSenderImpl mailSender = new JavaMailSenderImpl();
mailSender.setHost("mail.atyourplace.com");
mailSender.setUsername("sendingaccount@atyourplace.com");
mailSender.setPassword("password")

• Create a DB scheme “mail” in MariaDB and update the credentials
• Start the micro-service – preferebly in Docker container

Sending emails

This application consumes Kafka Messages Asynchroniously. Update the server where kafka is located in the application.properties:

kafka.address=localhost:9092

Besides that:

The Body of the Kafka Message is a String with encoded JSON Object with fields

• fromMail;
• toMail;
• subjectOfTheMail;
• textOfTheMail;

Web Admin Interface

The Micro Service has Web Admin Interace http://localhost:8701/emails_manager_app (or emails_manager_app-1.0-SNAPSHOT if the generated war is deployed).

There is hard-coded login as – it is intended to be hidden in your local network, but you could easily extend it and add your authentication.

There is a basic pagination view with the list of send mail messages.

And a basic add/edit/view screen. You will most likely be used for display only in real use case.

Product Packaging

You will receive emails_manager_app source code. You could build it with

mvn clean package -Pproduction -Dvaadin.force.production.build=true

docker build --build-arg JAR_FILE=target/*.jar -t com.programtom.emails_manager_app/Application. The command are included as scripts.