feat(gatling): improve Gatling integration

generators/java/generators/gatling/templates/README.md.jhi.gatling.ejs

@@ -1,9 +1,9 @@
 <&_ if (fragment.testingSection) { -&>
 ### Gatling
 
-Performance tests are run by [Gatling](https://gatling.io/) and written in Scala. They're located in [src/test/java/gatling/simulations](src/test/java/gatling/simulations).
+Performance tests are run by [Gatling](https://gatling.io/) and written in Java. They're located in [src/test/java/gatling/simulations](src/test/java/gatling/simulations).
 
-You can execute all Gatling tests with
+You can execute all Gatling tests with:
 
 ```bash
 <%_ if (buildToolMaven) { _%>
@@ -13,8 +13,47 @@ You can execute all Gatling tests with
 <%_ } _%>
 ```
 
+<%_ if (applicationTypeMicroservice) { _%>
+> **Note for microservice architectures:** Gatling tests in this microservice are designed to run via the **gateway**,
+> which handles authentication and routes requests to the microservice using the `/services/<%= baseName.toLowerCase() %>/` prefix.
+> Make sure the gateway is running before executing these tests.
+>
+> For **OAuth2/OIDC** architectures, the gateway is the only application that can authenticate users.
+> Run Gatling tests from the gateway project instead of this microservice directly.
+>
+> To override the target URL (defaults to the gateway at `http://localhost:<%= gatewayServerPort || 8080 %>`):
+> ```bash
+<%_ if (buildToolMaven) { _%>
+> ./mvnw gatling:test -DbaseURL=http://localhost:<%= gatewayServerPort || 8080 %>
+<%_ } else { _%>
+> ./gradlew gatlingRun -DbaseURL=http://localhost:<%= gatewayServerPort || 8080 %>
+<%_ } _%>
+> ```
+<%_ } else { _%>
+To override the target URL (defaults to `http://localhost:<%= serverPort %>`):
+```bash
+<%_ if (buildToolMaven) { _%>
+./mvnw gatling:test -DbaseURL=http://localhost:<%= serverPort %>
+<%_ } else { _%>
+./gradlew gatlingRun -DbaseURL=http://localhost:<%= serverPort %>
+<%_ } _%>
+```
+<%_ } _%>
+
+You can also control the number of concurrent users and ramp-up duration:
+
+```bash
+<%_ if (buildToolMaven) { _%>
+./mvnw gatling:test -Dusers=10 -Dramp=30
+<%_ } else { _%>
+./gradlew gatlingRun -Dusers=10 -Dramp=30
+<%_ } _%>
+```
+
 <&_ } -&>
 
 <&_ if (fragment.referenceSection) { -&>
 - [Gatling](https://gatling.io/)
+- [Gatling Maven Plugin](https://docs.gatling.io/reference/integrations/build-tools/maven-plugin/)
+- [Gatling Gradle Plugin](https://docs.gatling.io/reference/integrations/build-tools/gradle-plugin/)
 <&_ } -&>

generators/java/generators/gatling/templates/src/test/java/gatling/simulations/_entityClass_GatlingTest.java.ejs

@@ -39,12 +39,47 @@ import io.gatling.javaapi.http.HttpProtocolBuilder;
 /**
  * Performance test for the <%- entityClass %> entity.
  *
+<%_ if (applicationTypeMicroservice) { _%>
+ * <p>This simulation targets the <strong>gateway</strong> (default:
+ * {@code http://localhost:<%= gatewayServerPort || 8080 %>}) so that authentication works
+ * correctly. Microservices are OAuth2 resource-servers only — they cannot issue tokens
+ * themselves. All API calls are routed via the gateway's
+ * {@code /services/<%= baseName.toLowerCase() %>/} prefix.
+ *
+ * <p>Override the gateway URL at runtime:
+ * <pre>{@code
+ *   ./mvnw gatling:test -DbaseURL=http://gateway-host:8080
+ * }</pre>
+<%_ } else { _%>
+ * <p>By default this simulation targets {@code http://localhost:<%= serverPort %>}.
+ * Override at runtime:
+ * <pre>{@code
+ *   ./mvnw gatling:test -DbaseURL=http://localhost:<%= serverPort %>
+ * }</pre>
+<%_ } _%>
+ *
+ * <p>Control load:
+ * <pre>{@code
+ *   ./mvnw gatling:test -Dusers=50 -Dramp=60
+ * }</pre>
+ *
  * @see <a href="https://github.com/jhipster/generator-jhipster/tree/v<%- jhipsterVersion %>/generators/gatling#logging-tips">Logging tips</a>
  */
 public class <%- entityClass %>GatlingTest extends Simulation {
 
+<%_ if (applicationTypeMicroservice) { _%>
+    // For microservices with OAuth2, tests run against the gateway which handles authentication
+    // and routes requests to the microservice via /services/<%- baseName.toLowerCase() %>/
+    String baseURL = Optional.ofNullable(System.getProperty("baseURL")).orElse("http://localhost:<%- gatewayServerPort || 8080 %>");
+
+    // API path prefix for this microservice when accessed through the gateway
+    String apiPrefix = "/services/<%- baseName.toLowerCase() %>";
+<%_ } else { _%>
     String baseURL = Optional.ofNullable(System.getProperty("baseURL")).orElse("http://localhost:<%- serverPort %>");
 
+    String apiPrefix = "";
+<%_ } _%>
+
     HttpProtocolBuilder httpConf = http
         .baseUrl(baseURL)
         .inferHtmlResources()
@@ -53,7 +88,7 @@ public class <%- entityClass %>GatlingTest extends Simulation {
         .acceptLanguageHeader("fr,fr-fr;q=0.8,en-us;q=0.5,en;q=0.3")
         .connectionHeader("keep-alive")
         .userAgentHeader("Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:33.0) Gecko/20100101 Firefox/33.0")
-        .silentResources() // Silence all resources like css or css so they don't clutter the results
+        .silentResources() // Silence all resources like css or js so they don't clutter the results
 <%_ if (authenticationTypeOauth2) { _%>
         .disableFollowRedirect() // We must follow redirects manually to get the xsrf token from the keycloak redirect
         .disableAutoReferer()
@@ -155,12 +190,12 @@ public class <%- entityClass %>GatlingTest extends Simulation {
         .pause(10)
         .repeat(2).on(
             exec(http("Get all <%- entityInstancePlural %>")
-            .get("<% if (applicationTypeMicroservice) { %>/services/<%- baseName.toLowerCase() %><% } %>/api/<%- entityApiUrl %>")
+            .get(apiPrefix + "/api/<%- entityApiUrl %>")
             .headers(headersHttpAuthenticated)
             .check(status().is(200)))
             .pause(Duration.ofSeconds(10), Duration.ofSeconds(20))
             .exec(http("Create new <%- entityInstance %>")
-            .post("<% if (applicationTypeMicroservice) { %>/services/<%- baseName.toLowerCase() %><% } %>/api/<%- entityApiUrl %>")
+            .post(apiPrefix + "/api/<%- entityApiUrl %>")
             .headers(headersHttpAuthenticated)
             .body(StringBody("{" +
 <%_ for (const [idx, field] of fields.filter(f => !(f.id && f.autoGenerate)).entries()) { _%>
@@ -172,12 +207,12 @@ public class <%- entityClass %>GatlingTest extends Simulation {
             .pause(10)
             .repeat(5).on(
                 exec(http("Get created <%- entityInstance %>")
-                .get("<% if (applicationTypeMicroservice) { %>/services/<%- baseName.toLowerCase() %><% } %>${new_<%- entityInstance %>_url}")
+                .get(apiPrefix + "${new_<%- entityInstance %>_url}")
                 .headers(headersHttpAuthenticated))
                 .pause(10)
             )
             .exec(http("Delete created <%- entityInstance %>")
-            .delete("<% if (applicationTypeMicroservice) { %>/services/<%- baseName.toLowerCase() %><% } %>${new_<%- entityInstance %>_url}")
+            .delete(apiPrefix + "${new_<%- entityInstance %>_url}")
             .headers(headersHttpAuthenticated))
             .pause(10)
         );