Simple event driver architecture

An event-driven architecture uses events to trigger and communicate between decoupled services and is common in modern applications built with microservices.

Event-driven architectures have three key components: event producers, event routers, and event consumers. A producer publishes an event to the router, which filters and pushes the events to consumers. Producer services and consumer services are decoupled, which allows them to be scaled, updated, and deployed independently.

About app

Based on S3 + SQS + Lambda + SNS + Textract. Fully serveless

Function is able to extract all images which can be recognized by AWS Textract service.

To use AWS SES service in order to send email to random emails (not verified by AWS), you have to request disabling sandbox state

Requirements

Name	Version
terraform	>= 0.14.5
aws	>= 3.26

Usage (default folder for upload images is images/)

terraform init
terraform apply -var-file="default.tfvars"

Inputs

Name	Description	Type	Default	Required
lambda_role_name	Lambda role name	string	role_for_lambda	yes
lambda_role_policy_name	Lambda role name	string	lambda_policies	yes
dead_letter_queue_name	Lambda role name	string	dead-letter-queue-for-converter	yes
sqs_queue_name	Lambda role name	string	images-to-convert	yes
lambda_name	Lambda role name	string	pic_to_text_converter	yes
s3_name	Lambda role name	string	images-hosting-for-test-2021	yes
sqs_timeout_visibility	Lambda role name	number	240	yes
sqs_retention_period	Lambda role name	number	345600	yes
sqs_dead_letters_count	Lambda role name	number	2	yes
lambda_handler	Lambda role name	string	lambda_function.lambda_handler	yes
s3_path_for_images_input	Lambda role name	string	images/	yes
s3_path_for_images_output	Lambda role name	string	text-documents/	yes
s3_notification_events	Lambda role name	list(string)	["s3:ObjectCreated:*"]	yes
sqs_dead_letter_queue_visibility_timeout	Lambda role name	number	60	yes
message_retention_seconds	Lambda role name	number	1209600	yes
email_sender	Email which will be sender	string	John Doe <[email protected]>	yes

Outputs

Name	Description
s3_input_folder	Path for images to convert them

TODO

• S3 presigned URL
• ses email veritifaction (for sender)
• read object tag that contains email address
• try catch blocks
• implement logging tool
• config management
• adjust policies instead of wildcard