Serverless feature flags

The idea behind this is to add feature flags API that will utilise Serverless framework.

Schema

The idea for the initial basic schema will be following:

{
  featureName1: {
    state: true|false
  }
}

Todo

• Set up DynamoDB in serverless.yml - that is where the data will be persisted
• GET endpoint that will return a list of enabled features as defined in schema
• Write object transform array reducer for the object from DynamoDB to match the response schema
• Handler to use the response transform
• Change the directory structure: add "api" folder with "get", "put", etc. handlers
• Add POST handler - to add flag to DynamoDB
• POST handler - add check to see if a flag is already in the table, if so, throw error. Otherwise it would get overwritten
• Make use of AWS-SDK promises rather than callbacks
• Fix failing unit test
• Refactor the callbacks - repeated code all over the place
• Update the response HTTP error codes
• Add PUT handler - to update flag in DynamoDB
• Refactor the method that checks if returned value is empty plain object - either move to own module to make DRY or use lodash?
• Refactor the method that checks if no body has been passed to request - move to own module
• Add DELETE hander - to delete flag from DynamoDB
• Refactor the code to make use of DynamoDB parameters for it not to overwrite the value if it already in the table - saves us make the check ourselves
• All responses to be JSON
• Update the body element check to verify it is not empty - Mark as done as tests pass
• Add eslint
• Work out if should use 204 with no body or should respond with some sort of JSON response on successful calls
• Add a generic handler to be make code more DRY
• Add integration tests
• Refactor the code to move all the DynamoDB operations to its own "db/storage" module
• Add authentication mechanism for adding/removing/deleting features
• Cloudfront - configure the cache time for a very long time
• Cloudfront/AWS multi region fallback config?
• Add a clear cache trigger when the DynamoDB records is added/removed/updated
• Think of authentication mechanism for adding/removing/deleting features - for initial working scenario document and possibly add some scripts to talk to DynamoDB via AWS-SDK
• Document and possibly try to automate attaching a domain name

Long term ideas

• Explore how this can be integrated with MVT frameworks, and what it takes to build one