Reads headers from app service/client, adds missing headers, but not override existing headers, and forwards them to client/app service.
Traefik Plugin: https://plugins.traefik.io/plugins/62f3496be2bf06d4675b9445/add-missing-headers
GitHub: https://github.com/jerrywoo96/AddMissingHeaders
experimental:plugins:AddMissingHeaders:moduleName: github.com/jerrywoo96/AddMissingHeadersversion: v1.1.1
http:middlewares:AddMissingHeaders:plugin:AddMissingHeaders:requestHeaders:X-Custom-RequestHeader: CustomRequestHeaderresponseHeaders:X-Custom-ResponseHeader: CustomResponseHeader