[Traefik] - custom Header 추가

이슈
preflight request (XMLHttprequest) 를 위한 COS설정 필요

Traefik 처리방법 (custom Header 추가)

traefik.frontend.headers.customResponseHeaders : 
Access-Control-Allow-Methods:GET,OPTIONS,POST,DELETE,PUT||Access-Control-Allow-Origin:*||Access-Control-Allow-Headers:Origin,Accept,X-CSRF-Token,X-Requested-With,Content-Type,Access-Control-Request-Method,Access-Control-Request-Headers||Access-Control-Max-Age:360

참고 사항

1. preflight request flow

Unlike “simple requests” (discussed above), "preflighted" requests first send an HTTP request by the OPTIONS method to the resource on the other domain,
to determine if the actual request is safe to send. Cross-site requests are preflighted like this since they may have implications to user data.

• 실제 Main request 를 보내기 전에, 사전 (pre.. ) HTTP request ( OPTIONS) 으로 보내보는 것으로 이해 했음.

Traefik 에서 CORS 설정

• https://docs.traefik.io/v1.7/configuration/backends/docker/

Custom Header 를 직접 등록해서 사용할 수 있음 (굿!)

"LABEL" 에 추가.
traefik.frontend.headers.customResponseHeaders = Access-Control-Allow-Methods:GET,OPTIONS,POST,DELETE,PUT||Access-Control-Allow-Origin:*||Access-Control-Allow-Headers:Origin,Accept,X-Requested-With,Content-Type,Access-Control-Request-Method,Access-Control-Request-Headers||Access-Control-Max-Age:360

TEST 결과

• CURL TEST