fix: Fix IT testsuite following PR#104

Following #104, the `Host` http header became mandatory, else throwing a
NPE in Netty's code when reaching the NettyRoutingFilter code:

```
java.lang.NullPointerException: value
	at io.netty.util.internal.ObjectUtil.checkNotNull(ObjectUtil.java:39)
	Suppressed: The stacktrace has been enhanced by Reactor, refer to additional information below:
Error has been observed at the following site(s):
	*__checkpoint ⇢ org.springframework.cloud.gateway.filter.WeightCalculatorWebFilter [DefaultWebFilterChain]
	*__checkpoint ⇢ org.springframework.security.web.server.authorization.AuthorizationWebFilter [DefaultWebFilterChain]
	*__checkpoint ⇢ org.springframework.security.web.server.authorization.ExceptionTranslationWebFilter [DefaultWebFilterChain]
	*__checkpoint ⇢ org.springframework.security.web.server.authentication.logout.LogoutWebFilter [DefaultWebFilterChain]
	*__checkpoint ⇢ org.springframework.security.web.server.savedrequest.ServerRequestCacheWebFilter [DefaultWebFilterChain]
	*__checkpoint ⇢ org.springframework.security.web.server.context.SecurityContextServerWebExchangeWebFilter [DefaultWebFilterChain]
	*__checkpoint ⇢ org.springframework.security.web.server.authentication.AuthenticationWebFilter [DefaultWebFilterChain]
	*__checkpoint ⇢ org.springframework.security.web.server.context.ReactorContextWebFilter [DefaultWebFilterChain]
	*__checkpoint ⇢ org.springframework.security.web.server.header.HttpHeaderWriterWebFilter [DefaultWebFilterChain]
	*__checkpoint ⇢ org.springframework.security.config.web.server.ServerHttpSecurity$ServerWebExchangeReactorContextWebFilter [DefaultWebFilterChain]
	*__checkpoint ⇢ org.springframework.security.web.server.WebFilterChainProxy [DefaultWebFilterChain]
	*__checkpoint ⇢ org.springframework.boot.actuate.metrics.web.reactive.server.MetricsWebFilter [DefaultWebFilterChain]
	*__checkpoint ⇢ org.springframework.security.test.web.reactive.server.SecurityMockServerConfigurers$MutatorFilter [DefaultWebFilterChain]
	*__checkpoint ⇢ HTTP GET "/path/..." [ExceptionHandlingWebHandler]
Original Stack Trace:
		at io.netty.util.internal.ObjectUtil.checkNotNull(ObjectUtil.java:39)
		at io.netty.handler.codec.DefaultHeaders.fromObject(DefaultHeaders.java:1117)
		at io.netty.handler.codec.DefaultHeaders.addObject(DefaultHeaders.java:364)
		at io.netty.handler.codec.http.DefaultHttpHeaders.add(DefaultHttpHeaders.java:115)
		at org.springframework.cloud.gateway.filter.NettyRoutingFilter.lambda$filter$0(NettyRoutingFilter.java:139)
		at reactor.netty.http.client.HttpClient.headers(HttpClient.java:1038)
		at org.springframework.cloud.gateway.filter.NettyRoutingFilter.filter(NettyRoutingFilter.java:133)
		at org.springframework.cloud.gateway.handler.FilteringWebHandler$GatewayFilterAdapter.filter(FilteringWebHandler.java:137)
		at org.springframework.cloud.gateway.filter.OrderedGatewayFilter.filter(OrderedGatewayFilter.java:44)
		at org.springframework.cloud.gateway.handler.FilteringWebHandler$DefaultGatewayFilterChain.lambda$filter$0(FilteringWebHandler.java:117)
```

Tests: `mvn clean verify` on gateway subdir went fine 3 times in a row.

Notes:

* It might deserve a trace in the documentation that the `Host`
  header is now mandatory, somehow ?
* I did not have to patch every WebTestClient calls strangely enough,
  only the one expecting a `200 - OK` return code.

gateway/src/main/java/org/georchestra/gateway/accounts/admin/AccountManager.java

@@ -38,7 +38,8 @@ public interface AccountManager {
      * @param mappedUser the user {@link ResolveGeorchestraUserGlobalFilter}
      *                   resolved by calling
      *                   {@link GeorchestraUserMapper#resolve(Authentication)}
-     * @return the stored version of the user if it exists, otherwise an empty Optional
+     * @return the stored version of the user if it exists, otherwise an empty
+     *         Optional
      */
     Optional<GeorchestraUser> find(GeorchestraUser mappedUser);
 

gateway/src/main/java/org/georchestra/gateway/autoconfigure/app/CustomErrorAttributes.java

@@ -46,7 +46,7 @@
  * {@link java.net.UnknownHostException} and {@link java.net.ConnectException}
  * to {@link HttpStatus#SERVICE_UNAVAILABLE}
  */
-class CustomErrorAttributes extends DefaultErrorAttributes {
+public class CustomErrorAttributes extends DefaultErrorAttributes {
 
     @Override
     public Map<String, Object> getErrorAttributes(ServerRequest request, ErrorAttributeOptions options) {

gateway/src/test/java/org/georchestra/gateway/app/GeorchestraGatewayApplicationTests.java

@@ -29,6 +29,7 @@
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
+import org.georchestra.gateway.autoconfigure.app.CustomErrorAttributes;
 import org.georchestra.gateway.autoconfigure.app.ErrorCustomizerAutoConfiguration;
 import org.georchestra.gateway.security.ldap.extended.GeorchestraUserNamePasswordAuthenticationToken;
 import org.junit.jupiter.api.Test;
@@ -39,6 +40,7 @@
 import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
 import org.springframework.cloud.gateway.route.Route;
 import org.springframework.cloud.gateway.route.RouteLocator;
+import org.springframework.context.ApplicationContext;
 import org.springframework.core.env.Environment;
 import org.springframework.http.HttpStatus;
 import org.springframework.security.core.Authentication;
@@ -58,6 +60,8 @@ class GeorchestraGatewayApplicationTests {
     private @Autowired GeorchestraGatewayApplication application;
     private @Autowired WebTestClient testClient;
 
+    private @Autowired ApplicationContext context;
+
     @Test
     void contextLoadsFromDatadir() {
         assertEquals("src/test/resources/test-datadir", env.getProperty("georchestra.datadir"));
@@ -108,12 +112,13 @@ void makeSureWhoamiDoesNotProvideAnySensitiveInfo() {
     void errorCustomizerReturnsServiceUnavailableInsteadOfServerError() {
         Map<String, Route> routesById = routeLocator.getRoutes()
                 .collect(Collectors.toMap(Route::getId, Function.identity())).block();
-
+        assertThat(context.getBean(CustomErrorAttributes.class)).isNotNull();
         Route testRoute = routesById.get("unknownHostRoute");
         assertNotNull(testRoute);
         assertThat(testRoute.getUri()).isEqualTo(URI.create("http://not.a.valid.host:80"));
 
-        testClient.get().uri("/path/to/unavailable/service").exchange().expectStatus()
-                .isEqualTo(HttpStatus.SERVICE_UNAVAILABLE);
+        testClient.get().uri("/path/to/unavailable/service")//
+                .header("Host", "localhost")//
+                .exchange().expectStatus().isEqualTo(HttpStatus.SERVICE_UNAVAILABLE);
     }
 }

gateway/src/test/java/org/georchestra/gateway/security/ResolveGeorchestraUserGlobalFilterIT.java

@@ -64,6 +64,7 @@ protected void doStart() {
         assertNotNull(context.getBean(JsonPayloadHeadersContributor.class));
 
         testClient.get().uri("/echo/")//
+                .header("Host", "localhost")//
                 .header("Authorization", "Basic dGVzdGFkbWluOnRlc3RhZG1pbg==") // testadmin:testadmin
                 .exchange()//
                 .expectStatus()//
@@ -77,6 +78,7 @@ protected void doStart() {
         gatewayConfig.getDefaultHeaders().setJsonOrganization(Optional.of(false));
 
         testClient.get().uri("/echo/")//
+                .header("Host", "localhost")//
                 .header("Authorization", "Basic dGVzdGFkbWluOnRlc3RhZG1pbg==") // testadmin:testadmin
                 .exchange()//
                 .expectStatus()//
@@ -92,6 +94,7 @@ protected void doStart() {
         gatewayConfig.getDefaultHeaders().setJsonOrganization(Optional.of(true));
 
         testClient.get().uri("/echo/")//
+                .header("Host", "localhost")//
                 .header("Authorization", "Basic dGVzdGFkbWluOnRlc3RhZG1pbg==") // testadmin:testadmin
                 .exchange()//
                 .expectStatus()//

gateway/src/test/java/org/georchestra/gateway/security/accessrules/AccessRulesCustomizerIT.java

@@ -19,14 +19,10 @@
 
 package org.georchestra.gateway.security.accessrules;
 
-import static com.github.tomakehurst.wiremock.client.WireMock.equalTo;
-import static com.github.tomakehurst.wiremock.client.WireMock.get;
-import static com.github.tomakehurst.wiremock.client.WireMock.noContent;
-import static com.github.tomakehurst.wiremock.client.WireMock.ok;
-import static com.github.tomakehurst.wiremock.client.WireMock.urlMatching;
-
-import java.net.URI;
-
+import com.github.tomakehurst.wiremock.core.WireMockConfiguration;
+import com.github.tomakehurst.wiremock.junit5.WireMockExtension;
+import com.github.tomakehurst.wiremock.junit5.WireMockRuntimeInfo;
+import lombok.extern.slf4j.Slf4j;
 import org.georchestra.gateway.app.GeorchestraGatewayApplication;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
@@ -40,11 +36,9 @@
 import org.springframework.test.context.DynamicPropertySource;
 import org.springframework.test.web.reactive.server.WebTestClient;
 
-import com.github.tomakehurst.wiremock.core.WireMockConfiguration;
-import com.github.tomakehurst.wiremock.junit5.WireMockExtension;
-import com.github.tomakehurst.wiremock.junit5.WireMockRuntimeInfo;
+import java.net.URI;
 
-import lombok.extern.slf4j.Slf4j;
+import static com.github.tomakehurst.wiremock.client.WireMock.*;
 
 /**
  * Integration tests for {@link AccessRulesCustomizer} for the access rules in
@@ -133,8 +127,12 @@ private static void mockServiceTarget(DynamicPropertyRegistry registry, String s
                 .withHeader("sec-proxy", equalTo("true"))//
                 .willReturn(ok()));
 
-        testClient.get().uri("/header").exchange().expectStatus().isOk();
-        testClient.get().uri("/header/img/logo.png").exchange().expectStatus().isOk();
+        testClient.get().uri("/header")//
+                .header("Host", "localhost")//
+                .exchange().expectStatus().isOk();
+        testClient.get().uri("/header/img/logo.png")//
+                .header("Host", "localhost")//
+                .exchange().expectStatus().isOk();
     }
 
     /**
@@ -172,10 +170,12 @@ private static void mockServiceTarget(DynamicPropertyRegistry registry, String s
         mockService.stubFor(get(urlMatching("/import(/.*)?")).willReturn(ok()));
 
         testClient.get().uri("/import")//
+                .header("Host", "localhost")//
                 .exchange()//
                 .expectStatus().isOk();
 
         testClient.get().uri("/import/any/thing")//
+                .header("Host", "localhost")//
                 .exchange()//
                 .expectStatus().isOk();
     }
@@ -216,10 +216,12 @@ private static void mockServiceTarget(DynamicPropertyRegistry registry, String s
         mockService.stubFor(get(urlMatching("/analytics(/.*)?")).willReturn(ok()));
 
         testClient.get().uri("/analytics")//
+                .header("Host", "localhost")//
                 .exchange()//
                 .expectStatus().isOk();
 
         testClient.get().uri("/analytics/any/thing")//
+                .header("Host", "localhost")//
                 .exchange()//
                 .expectStatus().isOk();
     }
@@ -264,10 +266,12 @@ void testGlobalAccessRule() {
         mockService.stubFor(get(urlMatching("/mapstore(/.*)?")).willReturn(ok()));
 
         testClient.get().uri("/mapstore")//
+                .header("Host", "localhost")//
                 .exchange()//
                 .expectStatus().isOk();
 
         testClient.get().uri("/mapstore/any/thing")//
+                .header("Host", "localhost")//
                 .exchange()//
                 .expectStatus().isOk();
     }
@@ -281,6 +285,7 @@ void testQueryParamAuthentication_forbidden_when_anonymous() {
                 .expectStatus().is3xxRedirection();
 
         testClient.get().uri("/header")//
+                .header("Host", "localhost")//
                 .exchange()//
                 .expectStatus().isOk();
     }
@@ -291,10 +296,12 @@ void testQueryParamAuthentication_authorized_if_logged_in() {
         mockService.stubFor(get(urlMatching("/header(.*)?")).willReturn(ok()));
 
         testClient.get().uri("/header?login")//
+                .header("Host", "localhost")//
                 .exchange()//
                 .expectStatus().isOk();
 
         testClient.get().uri("/header")//
+                .header("Host", "localhost")//
                 .exchange()//
                 .expectStatus().isOk();
     }