MyStayBooking

Introduction

This is an online web platform which allows user with different roles (host or guest) to either uploading stay or reservating a stay. The stay search leverages the inverted index feature from ElasticSearch to search any stay locations that are within the target distance range w.r.t the target input reference location. The stay address will be converted to geo location (longtitude, latitude) by GeoCoding API while uploading the stay, and then being saved to ElasticSearch repository to achieve geo-based search.

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Backend Software Archigecture

Backend Software Design

Image Upload Service

1. Call the AWS S3 client to save media files

Stay Upload Service

Add Stay

1. Upload media files to object storage by image upload service
2. Save the stay information to stay repository
3. Save the stay location to location repository (extended from ElasticSearch repository)

Delete Stay

1. Find the stay from stay repository

2. Check if the reservations for this stay is empty or not:

   2.1 Delete the stay if its reservation list is empty

   2.2 Throw exception if this rrservation list is not empty

3. Delete the stay location information from location repository (extended from ElasticSearch repository)

Stay Search Service

1. Search the available stay locations that are within the given distance range (search param) w.r.t given search location (search param) by location repository (extended from ElasticSeatch repository)
2. Search the reserved stays that are within the given check-in and check-out dates by reservation date repository
3. Filter out the reserved stays from available stays
4. Filter out the stays that have less available guest number than the given required guess number (search param)

Authentication Service

First Time Login

1. Check if username exists on the user repository
2. Once the username is verified, return a new generated token

Future Login

1. Add a Jwt filter to do internal check on Spring security layer 1.1 Extract username from header information and make sure the token is within the header 1.2 Make sure token is not expired 1.3 Make sure the username is valid

Database Schema Design

Authority - indicates whether the user is geust or host

User - contains user information (username, password)

Stay - contains stay information (address, descirption, max guest number, name, stay image, list of stay reservation date, list of stay reservation)

Reservation - contains reservation information (stay id, check-in date, check-out date)

StayImage - contains stay image information (stay id, media url)

StayReservationDate - contains stay reserved date information (stay id, date)

One user can have multiple stays or reservations (1->N)

One stay can have multiple stay images, stay reserved dates, reservations (1->N)

Multiple reservations correspond to one stay (N->1)

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Install Elasticsearch on AWS EC2 Guideline

Step1: Launch AWS EC2

Step1.1: Select any ubuntu image with Free tier eligible tag for Amazon Machine Image (AMI)

Step1.2: Select t2.micro with Free tier eligible tag for instance type

Step1.3: Create new key pair with RSA key pair type and private key file format of .pem

Step1.4: Click Allow HTTPS traffic from internest and Allow HTTP traffic from internest as well on network setting

Step1.5: Click Launch instance to launche the EC2 instance

Step1.6: Select the Security tag of your EC2 instance, click your current security group, and add a new inbound rule with the follow configuration:

IP version: IPV4 Type: Custom TCP Protocol: TCP Port range: 9200 Source: 0.0.0.0/0

Step1.7: SSH into your EC2 instance:

chmod 600 <Your saved private key pem file from step1.3>

ssh -i <Your saved private key pem file from step1.3> ubuntu@<Your EC2 instance public IP address>

for example:

chmod 600 ~/Download/my_key.pem

ssh -i ~/Download/my_key.pem [email protected]

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Step2: Instance ElasticeSearch

Step2.1: Install JRE:

sudo apt update

sudo apt install default-jre

Step2.2: Install elasticsearch:

sudo apt install apt-transport-https

wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -

sudo sh -c 'echo "deb https://artifacts.elastic.co/packages/7.x/apt stable main" > /etc/apt/sources.list.d/elastic-7.x.list'

sudo apt update

sudo apt install elasticsearch

Step2.3: Config elasticsearch

sudo vim /etc/elasticsearch/elasticsearch.yml

Under network setting section:

uncomment network.host and change to network.host: 0.0.0.0

uncomment network.port and change to network.port: 9200

Under discovery section:

add discovery.type: single-node

Under various section:

xpack.security.enabled: true

Step2.4: Add user to your elasticsearch

sudo /usr/share/elasticsearch/bin/elasticsearch-users useradd <username> -p <password> -r superuser

for example:

sudo /usr/share/elasticsearch/bin/elasticsearch-users useradd zli -p 12345678 -r superuser

Step2.5: Launch your elasticsearch

sudo systemctl start elasticsearch

sudo systemctl status elasticsearch

Step2.6 Verify that your elasticsearch is running:

Method1: Open browser and type http://<Your EC2 instance public IP address>:9200

Method2: Ping your elasticsearch port:

sudo apt-get install telnet

telnet <Your EC2 instance public IP address> 9200

Step2.7 Open your application.properties, update your ES properties:

elasticsearch.username=<Your username>

elasticsearch.password=<Your password>

Maven clean and install. If you don't get any build error, it means that your ES connection is successfully. Otherwise the ElasticsearchConfig will complain and you can't build your application.