Gorkin

Gorkin is a backend service that provides access to an S3 Bucket, listing the folders and giving temporary access to files.

Architecture

Service Architecture

The application uses the following AWS services:

• AWS API Gateway for the REST API
• AWS Lambda for the processing
• AWS S3 to read the folders and files
• AWS CloudWatch to save logs

The application is created with the Serverless Framework to make it easier to manage and deploy. The entire architecture is described in the serverless.yml file.

Architecture diagram

Code Architecture

The code follows the "Hexagonal Architecture" pattern, also know as "Ports and Adapters".

How to run it

Requirements

• An AWS account
• AWS CLI
• Go 1.12.x
• Node 10.15.x (required for the Serverless Framework, which is intalled via NPM)
• Serverless Framework >=1.28.0

Running locally with SAM Local

Install SAM Local

npm install -g aws-sam-local

Build the Go Binary

make build

Start up sam local

sam local start-api

Call the endpoint

GET http://127.0.0.1:3000/folders?folder=folder1/

Example of local request

GET http://127.0.0.1:3000/folders

Example of local response

{
    "id": "root",
    "name": "root",
    "type": "folder",
    "children": {
        "folder1": {
            "id": "d41d8cd98f00b204e9800998ecf8427e",
            "name": "folder1",
            "type": "folder",
            "children": {
                "folder1_1": {
                    "id": "d41d8cd98f00b204e9800998ecf8427e",
                    "name": "folder1_1",
                    "type": "folder",
                    "children": {
                        "folder1_1_1": {
                            "id": "d41d8cd98f00b204e9800998ecf8427e",
                            "name": "folder1_1_1",
                            "type": "folder",
                            "children": {
                                "12362714-dzone-refcard215-microservices.pdf": {
                                    "id": "73a82eb7b09a2c5499cc76c2aefe52e2",
                                    "name": "12362714-dzone-refcard215-microservices.pdf",
                                    "type": "file",
                                    "children": null
                                },
                                "halo.txt": {
                                    "id": "9b1529ddfd06b2046b2615f58ad2829f",
                                    "name": "halo.txt",
                                    "type": "file",
                                    "children": null
                                }
                            }
                        }
                    }
                }
            }
        },
        "folder2": {
            "id": "d41d8cd98f00b204e9800998ecf8427e",
            "name": "folder2",
            "type": "folder",
            "children": {
                "BP-Diet-Roadmap-2019.pdf": {
                    "id": "5053efd24093110335a9a3c3c6dd17f8",
                    "name": "BP-Diet-Roadmap-2019.pdf",
                    "type": "file",
                    "children": null
                },
                "folder2_1": {
                    "id": "d41d8cd98f00b204e9800998ecf8427e",
                    "name": "folder2_1",
                    "type": "folder",
                    "children": {}
                }
            }
        },
        "foto.png": {
            "id": "1ca5cf539336c45b48ae2369a56b40bf",
            "name": "foto.png",
            "type": "file",
            "children": null
        }
    }
}

Reference documentation

Generating pre-signed URL for S3 in Go

https://docs.aws.amazon.com/sdk-for-go/v1/developer-guide/s3-example-presigned-urls.html

https://github.com/awsdocs/aws-doc-sdk-examples/tree/master/go/example_code/s3