About

This is a NodeJS application which uses Google OAuth to authenticate users and fetches attachments from their Gmail account based on the search query. The attachments are downloaded on the server and the unique attachment id is stored in the MongoDB database. We can then download the attachment by providing the attachment id.

UI Snapshot

Prerequisites

Setting up MongoDB Project

• Create a new cluster in MongoDB to store user and email data. Copy the connection string and add the MONGO_URI to the .env file

Setting up project in Google Cloud

• Go to Google Cloud Console and create a new project
• Enabling Google API
  • In sidemenu options, select APIs and Services -> Library -> Search for Gmail API and enable it
• Setting up the OAuth Screen
  • Inside APIs and Services -> OAuth Consent Screen -> Select User Type (Select External for testing) and click on Create
  • Now enter all the application details and click Save and Continue
  • Inside Scopes section -> Add Scopes -> Seach for Gmail API and select the /auth/gmail.readonly scope. This gives our app access to read the user's emails -> Save and Continue
  • If your application is still in Testing phase and you selected External user type in Step 1, you'll have to provide email ids of all the users who can access your app -> Save and Continue
  • Check the app summary and click Save
• Generating Credentials
  • Again in APIs and Services, select Credentials -> Create Credentials -> oAuth Client ID
  • Select Application Type (Web Application), add authorized origin (Use http://localhost:3000 if you don't have a Domain) and a callback URL where Google will send the response after OAuth (http://localhost:3000/auth/google/callback in our case). Also add this as CALLBACK_URL in the .env file
  • Save you client id and secret as GOOGLE_CLIENT_ID and GOOGLE_CLIENT_SECRET in the .env file

Setup

• Clone the github repo
• Open terminal, go to the directory and run npm i
• Make sure followed all the above steps and added all the variable as specified in the .sample.env inside the .env file
• Run npm run dev which will start a Nodejs server at localhost:3000

Contact

Please feel free to reach out to me at [email protected] in case you have any queries.