Image API

This stack creates a REST API using serverless architecture in AWS. Two features are available in the API, save an image from a URL to an S3 Bucket, and list all images saved on the Bucket.

Requirements

• Linux or MacOS
• Python 3.x
  • pip3 (python3 -m pip install --upgrade pip)
• AWS cli installed and configured [https://docs.aws.amazon.com/pt_br/cli/latest/userguide/cli-chap-install.html]
• Postman (only to test API calls, or any other AWS Signature compatible tool)

Deploy the infrastructure

First, you need to set your environment variables in order to customize resource names as you like:

• stack_name: CloudFormation Stack
• image_bucket: S3 Bucket that will store saved images
• lambda_bucket: S3 Bucket that will store Lambda functions

$ export stack_name=sample-image-api-stack \
         image_bucket=sample-image-api-saved-images \
         lambda_bucket=sample-image-api-functions

<To change these values later run "unset my_var" and run the export command again>

Deploys the infrastructure to AWS account that is configured in the awscli:

$ make create

*Additionally, you can run make update_stack to update your stack, and make destroy to tear down the environment.

Authentication & Endpoint URL

In order to secure authentication to requests, AWS Signature is used. Get outputs from the stack once the infrastructure is deployed running:

• The below cmdlet retrieve the keys and endpoints required for testing

make get_stack_info

AWS Signature params

AWS Signature parameters are required to be informed on the request:

• AccessKey: access key
• SecretKey: secret key
• Region: us-east-1
• Service: execute-api

List Images

Returns json data with images save in the S3 Bucket.

• URL

  /list_images

• Method:

  POST

• Data Params

  None

• Success Response:

  • Code: 200
    Content: { "saved_images": [ "image.png", "image1.png" ] }

• Error Response:

  Content: { result : "Failed to list images", error : "<error_stack>" }

Save Image

Saves image in a S3 bucket and logs additional information on a DynamoDB Table.

• URL

  /save_image

• Method:

  POST

• Data Params

  { "url": "https://a_sample_image_site.com/some_image.png","name": "my_image.png" }

• Success Response:

  • Code: 200
    Content: { "result" : "Saved successfully", "name" : name, "storage" : s3_path, "date" : date_time }

• Error Response:

  Content: { result : "Failed to save image", error : "<error_stack>" }

DynamoDB

The /save_image method also saves additional information to a DynamoDB table, query items in the table using the below cmdlet:

make query_dynamodb

Future improvements

• Encrypt S3 Bucket using KMS keys in Lambda
• Replace AWS Signature authentication method by tokens
• Create automated REST API tests

AWS Cloudformation Resources

• AWS::IAM::User
• AWS::IAM::AccessKey
• AWS::IAM::Role
• AWS::IAM::ManagedPolicy
• AWS::S3::Bucket
• AWS::S3::BucketPolicy
• AWS::ApiGateway::Account
• AWS::ApiGateway::Stage
• AWS::ApiGateway::RestApi
• AWS::ApiGateway::Deployment
• AWS::ApiGateway::RestApi
• AWS::Lambda::Function
• AWS::Logs::LogGroup
• AWS::DynamoDB::Table