3

I am trying to make a POST request to a keycloak REST API endpoint with a body with application/x-www-form-urlencoded values.

Here is a cURL of a request:

curl -X POST \
  https://auth.beyondtime-stage.io/auth/realms/master/protocol/openid-connect/token \
  -H 'cache-control: no-cache' \
  -H 'content-type: application/x-www-form-urlencoded' \
  -d 'username=admin&password=pass123&client_id=admin-cli&grant_type=password'

To my disappointment, I haven't found a way to do it with feign.

Here is one example of what I've tried:

@FeignClient(name = "beyondtime-io-kc-client", url = "${btio.keycloakUrl}", path = "/")
public interface KeycloakAdminClient {

    @PostMapping(name="realms/master/protocol/openid-connect/token", consumes = "application/x-www-form-urlencoded")
    String getAuthToken(@RequestParam("username") String username,
                        @RequestParam("password") String password,
                        @RequestParam("client_id") String clientId,
                        @RequestParam("grant_type") String grantType);

}

In my pom.xml, I am using:

spring-cloud-starter-openfeign 2.1.1.RELEASE

I've also tried adding feign-form dependency and @Param instead of @RequestParam, but no success.

MBozic
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2 Answers2

6

I found the solution here How to POST form-url-encoded data with Spring Cloud Feign

Feign client:

import com.beyondtime.recruitmentservice.seafarer.entity.AuthTokenRequest;
import com.beyondtime.recruitmentservice.seafarer.entity.KeycloakAccessToken;
import feign.codec.Encoder;
import feign.form.spring.SpringFormEncoder;
import org.springframework.beans.factory.ObjectFactory;
import org.springframework.boot.autoconfigure.http.HttpMessageConverters;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.cloud.openfeign.support.SpringEncoder;
import org.springframework.context.annotation.Bean;
import org.springframework.web.bind.annotation.*;
import java.util.List;

@FeignClient(name = "beyondtime-io-kc-client", url = "${btio.keycloakUrl}", path = "/", configuration = KeycloakAdminClient.Configuration.class)
public interface KeycloakAdminClient {

    @PostMapping(value="realms/master/protocol/openid-connect/token", consumes = "application/x-www-form-urlencoded")
    KeycloakAccessToken getAuthToken(@RequestBody AuthTokenRequest authTokenRequest);

    class Configuration {
        @Bean
        Encoder feignFormEncoder(ObjectFactory<HttpMessageConverters> converters) {
            return new SpringFormEncoder(new SpringEncoder(converters));
        }
    }
}

Request object:

@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
public class AuthTokenRequest {
    private String username;

    private String password;

    private String client_id;

    private String grant_type;

}

Response object:

@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
public class KeycloakAccessToken {
    @JsonProperty("access_token")
    private String accessToken;
}
MBozic
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1

Sometimes those workarounds/hacks or actual implementation (as are defined by library itself) are more complex and boilerplated than it's necessary.

In this case I think it's easier and faster just to encode the body by yourself.

@FeignClient(name = "exampleClient", url = "https://example.com")
interface ExampleClient {

    @PostMapping(
        path = ["/oauth2/token"],
        headers = ["Content-Type: application/x-www-form-urlencoded"],
        consumes = [MediaType.APPLICATION_FORM_URLENCODED_VALUE],
    )
    fun loginWithCode(@RequestBody request: String): LoginResponse
}

val urlEncodedRequest = { code: String ->
    mapOf(
        "grant_type" to "authorization_code",
        "client_secret" to "S3CR3T",
        "client_id" to "0DFD0SF75F67DSA",
        "code" to code,
    ).map { "${it.key}=${it.value}" }.joinToString("&")
}

The example is in Kotlin but the point is made.

Vergil333
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