I am having a requirement in which i have to forward a request to different endpoint by adding some extra headers(usually OAuth tokens).
i tried below working one to proxying request.
fun proxy(request: ServerRequest, url:String, customHeaders: HttpHeaders = HttpHeaders.EMPTY): Mono<ServerResponse> {
val modifiedHeaders = getHeadersWithoutOrigin(request, customHeaders)
var webClient = clientBuilder.method(request.method()!!)
.uri(url)
modifiedHeaders.forEach{
val list = it.value.iterator().asSequence().toList()
val ar:Array<String> = list.toTypedArray()
webClient.header(it.key, *ar)
}
return webClient
.body(request.bodyToMono(), DataBuffer::class.java).exchange()
.flatMap { clientResponse ->
ServerResponse.status(clientResponse.statusCode())
.headers{
it.addAll(clientResponse.headers().asHttpHeaders())
}
.body(clientResponse.bodyToMono(), DataBuffer::class.java)
}
}
Incoming requests always hit one proxy endpoint at my server with target url in header. At server, i read target url and add OAuth tokens and forward request to target URL. In this scenario, i do not want to parse response body. Send the response as it is down stream.
What is the reactive way to do it?
Related
I am quite new in Spring Cloud Feign and trying to send HTTP header which is required by service provider. Here is the code snippet
#FeignClient(name = "authentication", url = "http://localhost:3000/api")
public interface AuthenticationService {
#PostMapping(value = "/login")
JsonNode login(#RequestHeader("Origin") String origin, #RequestBody LoginParams parameters);
}
When I try to send Origin header then server does not receive this header. But other headers like referer or x-access-token are received at server successfully.
I have also tried using RequestInterceptor and was not successful to send Origin as header.
#Component
public class HeaderInterceptor implements RequestInterceptor {
#Override
public void apply(RequestTemplate requestTemplate) {
requestTemplate.removeHeader("origin");
requestTemplate.header("origin", "http://amjad.localhost:3000/");
}
}
Any hint or help would be much appreciated.
cheers!
I had similar issue with OpenFeign. "Origin" header was blocked by defult, because it was using old Java http client.
After change to OkHttp Client, "Origin" was sent.
Is there a way to capture response body in spring Webflux. I understand that its against the principles of reactive, however I would need to capture the body and return response. I am using ExchangeFilterFunction.
public Optional<ExchangeFilterFunction> buildEnricher() {
return Optional.of(ExchangeFilterFunction.ofResponseProcessor(clientResponse -> {
return clientResponse.bodyToMono(String.class)
.flatMap(body -> {
System.out.println(body);
return Mono.just(clientResponse);
});
}));
This will end up consuming the body and sending an empty client
response. Is there anyway I can send the body back too ?
You can choose to clone the client response.
ClientResponse responseClone = ClientResponse.from(clientResponse)
You can now drain the body from responseClone and return Mono.just(clientResponse)
I have a REST-like service I POST requests to using WebFlux WebClient. The service returns response in a common JSON format, something like:
{
"status": "OK",
"data": []
}
Now for each WebClient invocation for each endpoint I would like to perform common validation to check if status == "OK". Do I need to invoke the validation separately for each endpoint, e.g.
myClient.post().uri("/myEndpoint1")
//..
.retrieve()
.bodyToMono(MyResponse.class)
.map(this::validateResponse)
//..
Or is there a way to add some common processing while creating the WebClient. I tried using a filter
this.myClient = WebClient.builder()
.clientConnector(new ReactorClientHttpConnector(HttpClient.create().wiretap()))
.filter(ExchangeFilterFunction.ofResponseProcessor(this::validateMyResponseAsFilter))
.baseUrl(mybaseUrl)
.build();
where validateMyResponseAsFilter is
private Mono<ClientResponse> validateMyResponseAsFilter(ClientResponse resp) {
return resp.bodyToMono(MyResponse.class)
.flatMap(myResponse -> "OK".equals(myResponse.getStatus()) ? Mono.just(resp) : Mono.error(new RuntimeException()));
}
but this results in
org.springframework.web.reactive.function.UnsupportedMediaTypeException: Content type 'application/octet-stream' not supported for bodyType=my.package.MyResponse
Turned out that the service I connected to did not return Content-Type header. After fixing the service, the code works correctly.
I'm using Spring 5, Netty and Spring webflux to develop and API Gateway. Sometime I want that the request should be stopped by the gateway but I also want to read the body of the request to log it for example and return an error to the client.
I try to do this in a WebFilter by subscribing to the body.
#Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
if (enabled) {
logger.debug("gateway is enabled. The Request is routed.");
return chain.filter(exchange);
} else {
logger.debug("gateway is disabled. A 404 error is returned.");
exchange.getRequest().getBody().subscribe();
exchange.getResponse().setStatusCode(HttpStatus.NOT_FOUND);
return exchange.getResponse().writeWith(Mono.just(exchange.getResponse().bufferFactory().allocateBuffer(0)));
}
}
When I do this it works when the content of the body is small. But when I have a large boby, only the first element of the flux is read so I can't have the entire body. Any idea how to do this ?
1.Add "readBody()" to the post route:
builder.routes()
.route("get_route", r -> r.path("/**")
.and().method("GET")
.filters(f -> f.filter(myFilter))
.uri(myUrl))
.route("post_route", r -> r.path("/**")
.and().method("POST")
.and().readBody(String.class, requestBody -> {return true;})
.filters(f -> f.filter(myFilter))
.uri(myUrl))
2.Then you can get the body string in your filter:
String body = exchange.getAttribute("cachedRequestBodyObject");
Advantages:
No blocking.
No need to refill the body for further process.
Works with Spring Boot 2.0.6.RELEASE + Sring Cloud Finchley.SR2 + Spring Cloud Gateway.
The problem here is that you are subscribing manually within the filter, which means you're disconnecting the reading of the request from the rest of the pipeline. Calling subscribe() gives you a Disposable that helps you manage the underlying Subscription.
So you need to turn connect the whole process as a single pipeline, a bit like:
Flux<DataBuffer> requestBody = exchange.getRequest().getBody();
// decode the request body as a Mono or a Flux
Mono<String> decodedBody = decodeBody(requestBody);
exchange.getResponse().setStatusCode(HttpStatus.NOT_FOUND);
return decodedBody.doOnNext(s -> logger.info(s))
.then(exchange.getResponse().setComplete());
Note that decoding the whole request body as a Mono means your gateway will have to buffer the whole request body in memory.
DataBuffer is, on purpose, a low level type. If you'd like to decode it (i.e. implement the sample decodeBodymethod) as a String, you can use one of the various Decoder implementations in Spring, like StringDecoder.
Now because this is a rather large and complex space, you can use and/or take a look at Spring Cloud Gateway, which does just that and way more.
Is there an alternative to the session feature plugin in servicestack? In some scenarios I cannot use cookies to match the authorized session in my service implementation. Is there a possibility to resolve the session using a token in http header of the request? What is the preferred solution for that in case the browser is blocking cookies?
I'm using ServiceStack without the built-in auth and session providers.
I use a attribute as request filter to collect the user information (id and token), either from a cookie, request header or string parameter.
You can provide this information after the user takes login. You append a new cookie to the response and inject the id and token info on clientside when rendering the view, so you can use for http headers and query parameters for links.
public class AuthenticationAttribute : Attribute, IHasRequestFilter
{
public void RequestFilter(IHttpRequest request, IHttpResponse response, object dto)
{
var userAuth = new UserAuth { };
if(!string.IsNullOrWhiteSpace(request.GetCookieValue("auth"))
{
userAuth = (UserAuth)request.GetCookieValue("auth");
}
else if (!string.IsNullOrEmpty(request.Headers.Get("auth-key")) &&
!string.IsNullOrEmpty(request.Headers.Get("auth-id")))
{
userAuth.Id = request.Headers.Get("id");
userAuth.Token = request.Headers.Get("token");
}
authenticationService.Authenticate(userAuth.Id, userAuth.token);
}
public IHasRequestFilter Copy()
{
return new AuthenticationAttribute();
}
public int Priority { get { return -3; } } // negative are executed before global requests
}
If the user isn't authorized, i redirect him at this point.
My project supports SPA. If the user consumes the API with xmlhttprequests, the authentication stuff is done with headers. I inject that information on AngularJS when the page is loaded, and reuse it on all request (partial views, api consuming, etc). ServiceStack is powerful for this type of stuff, you can easily configure your AngularJS app and ServiceStack view engine to work side by side, validating every requests, globalizing your app, etc.
In case you don't have cookies and the requests aren't called by javascript, you can support the authentication without cookies if you always generate the links passing the id and token as query parameters, and pass them through hidden input on forms, for example.
#Guilherme Cardoso: In my current solution I am using a PreRequestFilters and the built-in session feature.
My workflow/workaround is the following:
When the user gets authorized I took the cookie and send it to the client by using an http header. Now the client can call services if the cookie is set in a http-header (Authorization) of the request.
To achieve this I redirect the faked authorization header to the cookie of the request using a PreRequestFilter. Now I am able to use the session feature. Feels like a hack but works for the moment ;-)
public class CookieRestoreFromAuthorizationHeaderPlugin : IPlugin
{
public void Register(IAppHost appHost)
{
appHost.PreRequestFilters.Add((req, res) =>
{
var cookieValue = req.GetCookieValue("ss-id");
if(!string.IsNullOrEmpty(cookieValue))
return;
var authorizationHeader = req.Headers.Get("Authorization");
if (!string.IsNullOrEmpty(authorizationHeader) && authorizationHeader.ToLower().StartsWith("basictoken "))
{
var cookie = Encoding.UTF8.GetString(Convert.FromBase64String(authorizationHeader.Split(' ').Last()));
req.Cookies.Add("ss-id",new Cookie("ss-id",cookie));
req.Items.Add("ss-id",cookie);
}
});
}
}