Plug pipeline wrapper: handling options

Plug.Builder can be used to build a plug pipeline, but it requires us to hardcode the options to the wrapped plugs. In my case I wanted to allow the users of the wrapper plug, distributed as part of a hex package, to provide the options to be passed down to the wrapped plugs, meaning I cannot specify the options in advance. I talked about how to use the Plug behaviour to write a new plug that wraps up a plug pipeline without using Plug.Builder, including also passing through the options to the underlying plugs.

Transcript

1. Dynamic Plug Pipeline Creating a plug pipeline with dynamic options
2. Package
 https://hex.pm/packages/clova Docs
 https://hexdocs.pm/clova Code
 https://github.com/line/clova-cek-sdk-elixir
3. 1.Parse JSON request 2.Validate message signature & app_id 3.Dispatch request to developer’s callback 4.Encode JSON response
4. 1.Parse JSON request 2.Validate message signature & app_id 3.Dispatch request to developer’s callback 4.Encode JSON response
5. 1.Parse JSON request 2.Validate message signature & app_id 3.Dispatch request to developer’s callback 4.Encode JSON response
6. 1.Parse JSON request 2.Validate message signature & app_id 3.Dispatch request to developer’s callback 4.Encode JSON response
7. 1.Parse JSON request 2.Validate message signature & app_id 3.Dispatch request to developer’s callback 4.Encode JSON response
20. https://github.com/line/clova-cek-sdk-elixir/blob/master/test/clova/skill_plug_test.exs