README.md

Image resize service

This service accepts an image in POST http request, and creates 2 resized images from it :

• 200px wide
• 75px wide

Then it uploads these 3 images (the original one and the two resized ones) to some publicly available S3

This nodejs service is deployed to AWS lambda functions, exposed via API gateway

Prerequisites

• An AWS account or IAM, with programmatic access
• Secrets are set up in github :
  • AWS_KEY : the AWS account access key
  • AWS_SECRET : the AWS account secret key

Used tools

This toolchain is used for CI/CD :

• Serverless framework
• github actions
• npm

Deployments

This service is deployed automatically on github events. See dedicated paragraph below.

Deployment leaves you with following installed infrastructure :

URL of the application

• DEV environment : https://xlhxubq14k.execute-api.eu-west-1.amazonaws.com/dev/image
• PROD environment : https://wbwnkacghl.execute-api.eu-west-1.amazonaws.com/prod/image

Address of resized images

• DEV environment : https://bsoille-resized-images-bucket-dev.s3.eu-west-1.amazonaws.com/
• PROD environment : https://bsoille-resized-images-bucket-prod.s3.eu-west-1.amazonaws.com/

Try it

In production environment, being said that you have an image img.jpg in your cwd:

curl --location --request POST 'https://wbwnkacghl.execute-api.eu-west-1.amazonaws.com/prod/image' \
--form 'file=@img.jpg' \
--form 's3Key=img.jpg'

Then, access your resized images at :

• https://bsoille-resized-images-bucket-prod.s3.eu-west-1.amazonaws.com/img.jpg
• https://bsoille-resized-images-bucket-prod.s3.eu-west-1.amazonaws.com/img.jpg_200
• https://bsoille-resized-images-bucket-prod.s3.eu-west-1.amazonaws.com/img.jpg_75

CI / CD

CI is running, some tests are performed on every push git command :

• Unit tests (none are there so far)
• Code scanning with codeQL
• serverless file format checking

This service is automatically deployed to dev and prod environments :

• on merge in master : deploy to DEV environment
• on tag (beginning with a 'v') : deploy to production

Final notes

Problems found

• There is no TU ; developer should add some
• There were security problems with node dependencies, quite fixed by changing packages-lock file ; developer should have a look

Logs

Logs are stored in cloudWatch.
Could be centralized in some datadog service and get easier to parse.

Tracing

Some metrics are displayed in dashboards at cloudWatch. Indeed, one dashboard gets created as per environment :

• DEV : dev-image-resizeDashboard
• PROD : prod-image-resizeDashboard

Yet to be done

• build some local environment with SAM or localstack