teqnation-serverless-voting

Voting Application in following 3 platforms:

• AWS
• AZURE
• GOOGLE

Overall Architecture for all the platforms is as per below:

1. AWS

Lambda functions in python for voting app

Architectural diagram of the application

Lambda Functions

• lambda_function_clean_db - This is a function which cleans are the documents in a MongoDB collection
• lambda_function_get - This is the lambda function which is used for Getting results after votes are casted.
• lambda_function - This is the function which is used to cast votes.

Download the dependencies for these lambda functions while using them.

• Refer the requiremnts.txt file for all the dependencies which you need to download to run these functions.
• use pip install -r requirements.txt

API Gateway

• Create API gateway to handle all 3 lambda functions mentioned above.

2. Microsoft Azure

Azure Functions

• delete_votes.py - This is a function which cleans are the documents in a MongoDB collection
• get_votes.py - This is the lambda function which is used for Getting results after votes are casted.
• cast_votes.py - This is the function which is used to cast votes.

API Management

• Create API Management gateway to handle all 3 Azure functions mentioned above.

3. Google Cloud

TBD

4. MongoDB

Here we are using MongoDB for storing an retrieving the votes. We have created MongoDB VM in each platform.

1. Installation of MongDB

• For MongoDB 3.0, create the below file using VI or any other editor:

vi /etc/yum.repos.d/mongodb-org-3.0.repo

• Add the following in the file

 [mongodb-org-3.0]
 name=MongoDB Repository
 baseurl=https://repo.mongodb.org/yum/amazon/2013.03/mongodb-org/3.0/x86_64/
 gpgcheck=0
 enabled=1

• Install MongoDB

sudo yum install -y mongodb-org

• Start MongoDB

sudo service mongod start

• Optionally - To ensure mongoDB starts automatically in case of reboot

sudo chkconfig mongod on

• Change the configuration file for MongoDB so as to accept traffic from anywhere over the Internet

vi /etc/mongod.conf

and change the IP from 127.0.0.1 to 0.0.0.0 as shown below:

# network interfaces
net:
  port: 27017
  bindIp: 0.0.0.0  # Listen to local interface only, comment to listen on all interfaces.

2. Some useful Commands for MongoDB

• To login to MongoDB

 mongo 

• list all the dbs in MongoDB

show dbs 

• Select the db which we are using

use vote_app_database

• show all the collections(tables)

 show collections

• to get all the data in each collection

 db.<COLLECTION_NAME>.find()
 e.g
 db.votes.find()

• to drop the collection(table), to clean up before testing

 db.<COLLECTION_NAME>.drop()
 e.g
 db.votes.drop()

• to clean the documents (items) in a collection in MongoDB

db.<COLLECTION_NAME>.delete_many({})
e.g
db.votes.delete_many({})