Add "root-path" to swagger-ui

extensions/swagger-ui/deployment/src/main/java/io/quarkus/swaggerui/deployment/SwaggerUiConfig.java

@@ -323,4 +323,9 @@ public interface SwaggerUiConfig {
      */
     @WithDefault("false")
     boolean tryItOutEnabled();
+
+    /**
+     * Custom root path. Useful when the application is behind a proxy with a custom root path.
+     */
+    Optional<String> rootPath();
 }

extensions/swagger-ui/deployment/src/main/java/io/quarkus/swaggerui/deployment/SwaggerUiProcessor.java

@@ -3,6 +3,7 @@
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.URI;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -27,6 +28,7 @@
 import io.quarkus.deployment.builditem.HotDeploymentWatchedFileBuildItem;
 import io.quarkus.deployment.builditem.LaunchModeBuildItem;
 import io.quarkus.deployment.builditem.ShutdownContextBuildItem;
+import io.quarkus.deployment.util.UriNormalizationUtil;
 import io.quarkus.devui.deployment.menu.EndpointsProcessor;
 import io.quarkus.maven.dependency.GACT;
 import io.quarkus.runtime.configuration.ConfigurationException;
@@ -108,7 +110,17 @@ public void getSwaggerUiFinalDestination(
 
             }
 
-            String openApiPath = nonApplicationRootPathBuildItem.resolvePath(openapi.path());
+            String openApiPath;
+            if (swaggerUiConfig.rootPath().isPresent()) {
+                URI root = UriNormalizationUtil.toURI("/", true);
+                openApiPath = UriNormalizationUtil.normalizeWithBase(
+                        root,
+                        swaggerUiConfig.rootPath().get()
+                                + nonApplicationRootPathBuildItem.resolvePath(openapi.path()),
+                        false).getPath();
+            } else {
+                openApiPath = nonApplicationRootPathBuildItem.resolvePath(openapi.path());
+            }
 
             String swaggerUiPath = nonApplicationRootPathBuildItem.resolvePath(swaggerUiConfig.path());
             ThemeHref theme = swaggerUiConfig.theme().orElse(ThemeHref.feeling_blue);
@@ -380,6 +392,12 @@ private byte[] generateIndexHtml(String openApiPath, String swaggerUiPath, Swagg
         if (swaggerUiConfig.queryConfigEnabled()) {
             options.put(Option.queryConfigEnabled, "true");
         }
+        if (swaggerUiConfig.rootPath().isPresent()) {
+            var rootPath = swaggerUiConfig.rootPath().get();
+            addRootPath(rootPath, Option.selfHref, options);
+            addRootPath(rootPath, Option.backHref, options);
+            addRootPath(rootPath, Option.oauth2RedirectUrl, options);
+        }
 
         ObjectMapper objectMapper = new ObjectMapper();
         Map<String, String> oauthAdditionalQueryStringParamMap = new HashMap<>();
@@ -439,6 +457,16 @@ private byte[] generateIndexHtml(String openApiPath, String swaggerUiPath, Swagg
         return IndexHtmlCreator.createIndexHtml(urlsMap, swaggerUiConfig.urlsPrimaryName().orElse(null), options);
     }
 
+    private void addRootPath(String rootPath, Option key, Map<Option, String> options) {
+        var value = options.get(key);
+        if (value != null) {
+            URI root = UriNormalizationUtil.toURI("/", true);
+            var behindRootPath = UriNormalizationUtil.normalizeWithBase(root, rootPath + value, false)
+                    .getPath();
+            options.put(key, behindRootPath);
+        }
+    }
+
     private static boolean shouldInclude(LaunchModeBuildItem launchMode, SwaggerUiConfig swaggerUiConfig) {
         return launchMode.getLaunchMode().isDevOrTest() || swaggerUiConfig.alwaysInclude();
     }

extensions/swagger-ui/deployment/src/test/java/io/quarkus/swaggerui/deployment/RootPathTest.java

@@ -0,0 +1,37 @@
+package io.quarkus.swaggerui.deployment;
+
+import static org.hamcrest.Matchers.containsString;
+
+import org.jboss.shrinkwrap.api.asset.StringAsset;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.test.QuarkusUnitTest;
+import io.restassured.RestAssured;
+
+public class RootPathTest {
+
+    @RegisterExtension
+    static final QuarkusUnitTest config = new QuarkusUnitTest()
+            .withApplicationRoot((jar) -> jar
+                    .addAsResource(new StringAsset(
+                            "quarkus.swagger-ui.root-path=/nginx/path"), "application.properties"));
+
+    @Test
+    public void shouldUseCustomRootPath() {
+        RestAssured.when().get("/q/swagger-ui").then().statusCode(200).body(containsString("/nginx/path/q/openapi"));
+        RestAssured.when().get("/q/swagger-ui/index.html").then().statusCode(200).body(containsString("/nginx/path/q/openapi"));
+        RestAssured.when().get("/q/swagger-ui").then()
+                .statusCode(200)
+                .body(containsString("/nginx/path/q/swagger-ui/oauth2-redirect.html"));
+        RestAssured.when().get("/q/swagger-ui/index.html").then()
+                .statusCode(200)
+                .body(containsString("/nginx/path/q/swagger-ui/oauth2-redirect.html"));
+        RestAssured.when().get("/q/swagger-ui").then()
+                .statusCode(200)
+                .body(containsString("/nginx/path/q/swagger-ui"));
+        RestAssured.when().get("/q/swagger-ui/index.html").then()
+                .statusCode(200)
+                .body(containsString("/nginx/path/q/swagger-ui"));
+    }
+}

extensions/vertx-http/deployment/src/main/java/io/quarkus/vertx/http/deployment/NonApplicationRootPathBuildItem.java

@@ -109,7 +109,7 @@ public String getNonApplicationRootPath() {
     }
 
     /**
-     * @return the normalized root path for the mangement endpoints. {@code getNonApplicationRootPath()} if the
+     * @return the normalized root path for the management endpoints. {@code getNonApplicationRootPath()} if the
      *         management interface is disabled.
      */
     public String getManagementRootPath() {