Send email from bash or shell script by using SendGrid API

sendgrid.sh

#!/bin/bash

#-----------------------------
# REFERENCES
# https://sendgrid.com/docs/API_Reference/Web_API_v3/Mail/index.html
# https://sendgrid.com/docs/for-developers/sending-email/curl-examples/
# https://sendgrid.com/docs/API_Reference/Web_API_v3/How_To_Use_The_Web_API_v3/errors.html
#-----------------------------

SUBJECT="🗄️ Backup Reports";
SENDGRID_API_KEY=""
EMAIL_TO="[email protected]"
FROM_EMAIL="[email protected]"
FROM_NAME="Backup Server"

if [ ! -z "$SENDGRID_API_KEY" ] && [ "$SENDGRID_API_KEY" != "" ]; then
    # Attachment needs to be base64 encoded
    REPORTS=$(base64 reports.txt)
    
    # Prepare the recipe
    REQUEST_DATA='{
        "personalizations": [{ 
            "to": [{ "email": "'"$EMAIL_TO"'" }],
        }],
        "subject": "'"$SUBJECT"'",
        "from": {
            "email": "'"$FROM_EMAIL"'",
            "name": "'"$FROM_NAME"'" 
        },
        "content": [{
            "type": "text/html",
            "value": "Team, <br><br> Here are the logs🗒 of backup script for today, Hope everything is okay and you have a nice day 🎉😁<br><br>Regards,<br>Backup Bot🤖"
        }],
        "attachments": [{
            "content": "'"$REPORTS"'",
            "type": "text/plain",
            "filename": "reports.txt"
        }]
    }';
    
    # Shoot the email
    curl -X "POST" "https://api.sendgrid.com/v3/mail/send" \
        -H "Authorization: Bearer $SENDGRID_API_KEY" \
        -H "Content-Type: application/json" \
        -d "$REQUEST_DATA"
fi