Custom Host Header not forwarded by Feign Client

Question

I am trying to send a custom host header using feign client, but the consumer application is not picking them. I am using spring boot feign and not openfeign.

Apart from Host, everyother header seems to be working as expected.

 ResponseEntity<JSONObject> list(@PathVariable("name") String name,
            @RequestParam("id") String id, @RequestParam("modelName") String modelName,
            @RequestHeader(value = "Authorization", required = true) String authorizationHeader,
            @RequestHeader(value = "Host", required = true) String hostName);

When i pass hostname as "xyz.com" the consumer application is still taking default host header.

In Consumer code when i read value of Host header from controller class, i do not get zyz.com. instead it picks from dns name.

Answer 1

Same problem happened for me - the @Param and @Headers didn't work for the "Host" header. Two things that I changed solved the issue - use OkHttpClient, and add a requestInterceptor when building the client:

client = Feign.builder()
    .client(new OkHttpClient())
    .requestInterceptor(request -> request.header("Host", hostHeaderValue))
    .target(MyClient.class, url);

Answer 2

The solution is included in the springframework. Add in the your property file:

feign.okhttp.enabled = true

And add the dependency of okhttp3, example in pom

<dependency>
  <groupId>com.squareup.okhttp3</groupId>
  <artifactId>okhttp</artifactId>
</dependency>

You can find more informations here

Answer 3

you can try System.setProperty("sun.net.http.allowRestrictedHeaders", "true"); to allow usage of restricted headers

see https://github.com/OpenFeign/feign/issues/747