/elm-aws-core

Make authenticated REST requests to AWS services using Elm

Primary LanguageElmApache License 2.0Apache-2.0

Contacts for Support

Status

  • 09-May-2021 - Published as version 9.0.0

The PATCH HttpMethod was added.

  • 25-Aug-2020 - Published as version 8.1.0

The model for AWS service specs and JSON codecs for it were added.

  • 17-Aug-2020 - Published as version 8.0.0

Error handling has been implemented. A separate error decoder can be specified when building a request. There are ready implemented ones for the standard error format, and for the case where no application level error is expected.

  • 11-May-2020 - Published as version 6.0.0

The API has been redesigned. The intermediate .Core. module name has been removed. The old Encode and Decode modules were dropped as not very useful and poorly designed.

A new KVEncode module has been introduced to help with building headers and query parameters. A KVDecoder module has been introduced to help decoding response headers, it is simpler than KVEncode as less elaborate encoding schemes are needed.

AWS URI encoding was taken from the old Encode module and put in its own Uri module.

ServiceConfig and Credentials were made into type aliases instead of opaque custom types. This mean the accessor functions could be dropped. I don't see any reason to make these things opaque, there is no advantage in hiding the implementation.

Service building was rationalized to remove some oddities. The ServiceConfig is now a simple record and easy to understand. The defaulting is explained in the docs. The defaulting happens behind the scenes when turning a config into a Service.

An amount of unused code was deleted. The API is now leaner and cleaner.

elm-aws-core

This package provides the functionality needed to make HTTP requests to AWS services.

All AWS service calls must be signed correctly, in order to pass on the authorized credentials of the caller to the service. AWS has multiple signing schemes that different services use, specifically 'S3' and 'V4'.

The AWS service portfolio is large with variations in signing schemes, AWS regions and service protocols across it. The aim of this package is to provide functions to build signed HTTP requests correctly for all of the services available on AWS. The specific service interface can then be implemented with this package as a foundational element.

Modules in this package

  • AWS.Config: Build a ServiceConfig describing the protocol, signing scheme, base URL and so on for a service.
  • AWS.Service: Turn a ServiceConfig into a Service definition, needed to make HTTP calls to that service.
  • AWS.Http: Build requests, sign and send them and decode the responses. Signing and sending a request requires both a Service and some Credentials.
  • AWS.Credentials: Create AWS Credentials used to sign requests.
  • AWS.KVEncode: Utility for helping to encode Elm data into key-valued string pairs, for setting query parameters or header fields.
  • AWS.KVDecode: Utility for decoding key-values string pairs into Elm data. Simpler than KVEncode as only needed for interpreting fairly simple response headers.
  • AWS.Uri: Utility for URI encoding specific to how AWS does it.