Chatter backend with Apollo PubSub and Redis PubSub

• For Production solution, i used Redis, please see the list event-publishing system
• In this solution, we are using Redis PubSub for AWS Production server
• On Local server, we are still using the normal Apollo PubSub comes with NESTJS. See pubsub.module.ts
• By default, Javascript objects are serialized using the JSON.stringify and JSON.parse methods. This means that not all objects - such as Date or Regexp objects - will deserialize correctly without a custom reviver, that work out of the box with the default in-memory implementation. In our case, ObjectId, Date in MessageDocument will need a custom reviver.
• Notes: The data we receive from Redis PubSub will need to be deserialized to JSON format in message.service.ts, before the resolvers can handle it. For this we are using custom-reviver

Install nest config and Mongo DB connection

NodeJS v20X npm i @nestjs/config @nestjs/mongoose mongoose npm i joi

Installing local Mongo DB

https://www.mongodb.com/docs/manual/tutorial/install-mongodb-on-os-x/

brew tap mongodb/brew brew update brew install mongodb-community@7.0

Using Mongo DB

• kill MongoDB process: https://stackoverflow.com/questions/11774887/how-to-stop-mongo-db-in-one-command mkdir -p ~/data/db chmod 777 ~/data/db mongod --dbpath ~/data/db

  • Normally MongoDb will be started on 127.0.0.1:27017

  • Connection string should be mongodb://127.0.0.1:27017/chatter

  • How to use MongoDB Model

  • How to use MongoDb method

  • MongoDB aggregate commands

NestJs GraphQL

• Installing: npm i @nestjs/graphql @nestjs/apollo @apollo/server graphql
• Playground GraphQL server, after starting backend: http://localhost:3001/graphql
• Understand NestJS GraphQL: https://docs.nestjs.com/graphql/quick-start

Running MongoDB Compass to view the MongoDB

https://www.mongodb.com/try/download/compass https://www.mongodb.com/docs/compass/current/query/filter/?utm_source=compass&utm_medium=product

Using migrate-mongo package to manage DB migration

npm i migrate-mongo npm i --save-dev @types/migrate-mongo

Install auth module with @nest/passport

nest g module auth nest g service auth

Decoding the retrieved Authentication cookie from jwt.io

Install common practices Field Validation and annotate email and password

npm i --save class-validator class-transformer ValidationPipe

AWS Backend deployment with self-signed SSL certificate

• Using self-signed SSL certificate (not recommended in production environment)

openssl version
openssl genrsa 2048 > privatekey.pem
stat privatekey.pem

openssl req -new -key privatekey.pem -out csr.pem

Country Name (2 letter code) [AU]:US
State or Province Name (full name) [Some-State]:Washington
Locality Name (eg, city) []:Seattle
Organization Name (eg, company) [Internet Widgits Pty Ltd]:Example Corporation
Organizational Unit Name (eg, section) []:Marketing
Common Name (e.g. server FQDN or YOUR name) []:prod.eba-cnqkbmvr.us-west-2.elasticbeanstalk.com
Email Address []:thangtran3112@gmail.com

Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:sometestpassword
An optional company name []:

openssl x509 -req -days 365 -in csr.pem -signkey privatekey.pem -out public.crt

• Upload public.crt to AWS Beanstalk with AWS CLI brew install awscli aws --version aws configure

AWS Access Key ID [None]: ************************
AWS Secret Access Key [None]: *************************************
Default region name [None]: us-west-2
Default output format [None]:

aws iam upload-server-certificate --server-certificate-name elastic-beanstalk-x509 --certificate-body file://public.crt --private-key file://privatekey.pem

Enable CORS on NESTJS backend

• Enable CORS in main.ts through app.enableCors();
• Enable CORS for GraphQLModule inside app.module.ts through cors: true

Backend Setting Cookie issue

• By default, AWS does not allow setting cookie with different CORS origin