Here’s a quick tip for handling CORS request in your akka-http based microservice: Create the following trait – CORSHandler
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trait CORSHandler{ private val corsResponseHeaders = List( `Access-Control-Allow-Origin`.*, `Access-Control-Allow-Credentials`(true), `Access-Control-Allow-Headers`("Authorization", "Content-Type", "X-Requested-With") ) //this directive adds access control headers to normal responses private def addAccessControlHeaders: Directive0 = { respondWithHeaders(corsResponseHeaders) } //this handles preflight OPTIONS requests. private def preflightRequestHandler: Route = options { complete(HttpResponse(StatusCodes.OK). withHeaders(`Access-Control-Allow-Methods`(OPTIONS, POST, PUT, GET, DELETE))) } // Wrap the Route with this method to enable adding of CORS headers def corsHandler(r: Route): Route = addAccessControlHeaders { preflightRequestHandler ~ r } // Helper method to add CORS headers to HttpResponse // preventing duplication of CORS headers across code def addCORSHeaders(response: HttpResponse):HttpResponse = response.withHeaders(corsResponseHeaders) } |
For using this trait in an actual route, we take the example route given in Akka Documentation and wrap the route with our corsHandler method defined in the above trait as follows:
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get { // Using the CORSHandler in our actual routes corsHandler( pathSingleSlash { complete(HttpEntity(ContentTypes.`text/html(UTF-8)`, "<html><body>Hello world!</body></html>")) } ~ path("ping") { complete("PONG!") } ~ path("crash") { sys.error("BOOM!") } ) } |
Explanation: This trait gives us a simple way to add…