There is a frontend application, a backend server, a daemon service (for writing data to database) and a mysql database instance.

#1. A user uploads a CSV through web UI which makes an POST /upload API call.

#2. POST /upload saves uploaded file to a configured upload directory and returns HTTP 201 status code with a jobId on success.

#3. The file uploaded in the upload directory gets automatically picked up by a deamon service (which continuously watches the upload directory) for processing. The deamon process parses the file and writes to the mysql database. On successful file processing, the file is removed from the upload directory. However, if the error occur either on parsing or writing, the file is moved to another directory called error directory.

#4. Web app polls GET /upload with jobId to get the status of the file processing. The status could be fail, success or in-progress.

#5. GET /upload endpoint returns in-progress when file (related to jobId) is found under upload directory, fail when file is found under error directory or success when file is present neither in upload directory nor in error directory.

#6. Once the file processing is done successfully, the payroll report table is automatically reloaded with new data by fetching the latest contents from GET /report.

First of all, make sure you have node and npm installed on your system. It can be installed by simply running following command on Mac terminal:

brew install node

To check whether you have got node and npm, run following commands:

node -v
npm -v

Refer. https://nodejs.org/en/download/package-manager/ for node installation instructions on other OS.

1. Go to cd wave-payroll-frontend.

2. Install all dependencies of frontend application first. Run npm i.

3. Start application npm start.

4. Open http://localhost:3000/ on your browser.

1. Go to cd wave-payroll-backend.

2. Install dependencies by running npm i.

3. Update config.json and provide uploadDir and errorDir paths. (create two empty directory and update paths)

4. Start server.

Either

npm start

Or

pm2 start app.js

It is recommended to use pm2 to make sure our server remain alive forever.

To install pm2, run npm install pm2 -g.

1. Go to cd wave-payroll-backend.

2. Start service.

Either

node ./api/lib/save_to_db_deamon.js

Or

pm2 start ./api/lib/save_to_db_deamon.js

Note: The backend and daemon service combined logs can be viewed by running following command:

pm2 logs 

MySql database instance is already up and running on AWS. No need to do any special setup there.

That's it! Start playing. Go to http://localhost:3000/.