datasources: ClearAuthHeadersMiddleware: refactor (#113707)

* refactor: extract logic

* directly use the setting.cfg in the middleware

* more granular config handling, per section

* fixed unit test

* refactor code to avoid lint error

pkg/services/pluginsintegration/clientmiddleware/clear_auth_headers_middleware.go

@@ -6,21 +6,26 @@ import (
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
 
 	"github.com/grafana/grafana/pkg/services/contexthandler"
+	"github.com/grafana/grafana/pkg/setting"
 )
 
 // NewClearAuthHeadersMiddleware creates a new backend.HandlerMiddleware
 // that will clear any outgoing HTTP headers that was part of the incoming
 // HTTP request and used when authenticating to Grafana.
-func NewClearAuthHeadersMiddleware() backend.HandlerMiddleware {
+func NewClearAuthHeadersMiddleware(cfgJWTAuth *setting.AuthJWTSettings, cfgAuthProxy *setting.AuthProxySettings) backend.HandlerMiddleware {
 	return backend.HandlerMiddlewareFunc(func(next backend.Handler) backend.Handler {
 		return &ClearAuthHeadersMiddleware{
-			BaseHandler: backend.NewBaseHandler(next),
+			BaseHandler:  backend.NewBaseHandler(next),
+			cfgJWTAuth:   cfgJWTAuth,
+			cfgAuthProxy: cfgAuthProxy,
 		}
 	})
 }
 
 type ClearAuthHeadersMiddleware struct {
 	backend.BaseHandler
+	cfgJWTAuth   *setting.AuthJWTSettings
+	cfgAuthProxy *setting.AuthProxySettings
 }
 
 func (m *ClearAuthHeadersMiddleware) clearHeaders(ctx context.Context, h backend.ForwardHTTPHeaders) {
@@ -30,11 +35,9 @@ func (m *ClearAuthHeadersMiddleware) clearHeaders(ctx context.Context, h backend
 		return
 	}
 
-	list := contexthandler.AuthHTTPHeaderListFromContext(ctx)
-	if list != nil {
-		for _, k := range list.Items {
-			h.DeleteHTTPHeader(k)
-		}
+	items := contexthandler.GetAuthHTTPHeaders(m.cfgJWTAuth, m.cfgAuthProxy)
+	for _, k := range items {
+		h.DeleteHTTPHeader(k)
 	}
 }