LetterOpenerWeb::S3

Amazon S3 storage backend for letter_opener_web.

This gem allows you to store email letters and attachments on Amazon S3 instead of the local filesystem, enabling multi-instance deployments on platforms like Heroku, Kubernetes, or any containerized environment.

Add this line to your application's Gemfile:

gem 'letter_opener_web'
gem 'letter_opener_web-s3', require: 'letter_opener_web_s3'

And then execute:

bundle install

Set up your AWS credentials and S3 bucket in your Rails configuration file (e.g., config/environments/development.rb):

# Require the gem first
require 'letter_opener_web_s3'

LetterOpenerWeb.configure do |config|
  # Use the S3 storage backend
  config.letter_class = LetterOpenerWeb::S3Letter

  # AWS Configuration
  config.aws_access_key_id = ENV['AWS_ACCESS_KEY_ID']
  config.aws_secret_access_key = ENV['AWS_SECRET_ACCESS_KEY']
  config.aws_region = 'us-east-1'
  config.aws_bucket = 'my-app-development-emails'
  config.aws_bucket_prefix = 'letters'  # Optional, defaults to 'letters'
end

Update your ActionMailer configuration to use the S3 delivery method:

config.action_mailer.delivery_method = :letter_opener_web_s3

Emails are stored in S3 with the following structure (using default prefix letters):

YOUR-BUCKET-NAME/
└── letters/                    # Configurable via aws_bucket_prefix
    ├── {timestamp_id_1}/
    │   ├── plain.html
    │   ├── rich.html
    │   └── attachments/
    │       ├── file1.pdf
    │       └── file2.jpg
    └── {timestamp_id_2}/
        └── ...

You can customize the prefix by setting config.aws_bucket_prefix to organize emails under different paths in your bucket.

The gem is available as open source under the terms of the MIT License.