go-modular-rest-api-dynamodb

README

Go Modular REST API (POC w/ DynamoDB)

• Go Modular REST API (POC w/ DynamoDB)
  • Testing
  • How it works
    • Entities
    • Rules
    • Adapters
    • Routes, Handlers, and Interfaces
    • Healthcheck, HTTP responses, and Logging
    • A few noteworthy functions
    • CORS

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NOTE: This repo is a POC.

While the structure seems monolithic, the objective is to build a modular REST API out of submodules.

This API will easily scale to 10k concurrent connections with zero issues.

The modularity allows a concurrent separation of concerns with multiple levels of abstraction, particularly due to a heavy use of interfaces.

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Testing

1. Make sure you have ~/.aws/credentials and ~/.aws/config configured.

2. At the project root, run go run ./app/main.go.

3. Use curl, Postman, or whatever tool you prefer to test routes.

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How it works

This API publishes at port 8080; configure in config.go.

When the API starts, it opens a session to DynamoDB by loading credentials from ~/.aws/credentials and the region from ~/.aws/config.

The following routes are configured:

• /healthcheck
• /object

Entities

Entities are a represenation of DynamoDB objects and have two parts:

• Base which is the baseline metadata for an object such as its ID, creation and update timestamp.
• The actual Object, which consists of its Base and its Name.

Rules

Rules perform operations such as marshalling/unmarshalling returned data to a struct, creating new tables, and validating data before its processed. When data is marshalled/unmarshalled, it is processed to/from JSON via structs.

Adapters

Adapters handle database table functions.

Routes, Handlers, and Interfaces

When a route is accessed, its Handler hands off operations to Interfaces, and the Interfaces perform the database operations.

The following Interfaces are configured in to parts: Control level interfaces and Adapter level interfaces. The Control level functions rely on the Adapter level functions in a one-to-one relationship.

Control interface functions:

• Create() — standard Create operation.
• DescribeOne() — standard Read operation; applies to a single object.
• DescribeAll() — standard Read operation; applies to all objects.
• Update() — standard Update operation.
• Remove() — standard Delete operation.

Adapter interface functions:

• Create — standard Create operation.
• FindOne() — standard Read operation; applies to a single object.
• FindAll() — standard Read operation; applies to all objects.
• Update — standard Update operation.
• Delete — standard Delete operation.

Healthcheck, HTTP responses, and Logging

Healthcheck is configured at healthcheck.go with the following HTTP statuses:

HTTP Status	Description
200	Service OK
204	No Content
400	Bad Request
404	Not Found
405	Method Not Allowed
409	Conflict
500	Internal Server Error

HTTP responses are configured at response.go.

Logging is configured at logger.go.

A few noteworthy functions

• Migrate() in object.go allows you to migrate your tables.
• checkTables() in main.go performs error handling to check that the DynamoDB table exists.

CORS

Cross-Origin Resource Sharing (CORS) is enabled by default; configure in routes.go.