issues/269 redirect user to first available app when proxy.landing-page=auto

Allows ShinyProxy to use the first available app for a logged-in user as landing page, bypassing the built-in index page. This can be used when different permissions for different users makes it impractical to identify an app which is accessible by all users in the system and usable as predefined landing page/app.

Author: nickmelis

src/main/java/eu/openanalytics/shinyproxy/controllers/IndexController.java

@@ -41,6 +41,8 @@
 @Controller
 public class IndexController extends BaseController {
 
+	private static final String PROXY_LANDING_PAGE_AUTO_OPTION = "auto";
+
 	@Inject
 	private ShinyProxySpecProvider shinyProxySpecProvider;
 
@@ -57,13 +59,20 @@ public void init() {
 	@RequestMapping("/")
     private Object index(ModelMap map, HttpServletRequest request) {
 		String landingPage = environment.getProperty("proxy.landing-page", "/");
-		if (!landingPage.equals("/")) return new RedirectView(landingPage);	
+		if (!landingPage.equals("/") && !landingPage.equals(PROXY_LANDING_PAGE_AUTO_OPTION)) {
+			return new RedirectView(landingPage);
+		}
 
 		prepareMap(map, request);
 
 		ProxySpec[] apps = proxyService.getProxySpecs(null, false).toArray(new ProxySpec[0]);
 		map.put("apps", apps);
 
+		// If set to `auto`, redirect to the first available app in the list
+		// See https://github.com/openanalytics/shinyproxy/issues/269
+		if (apps.length > 0 && landingPage.equals(PROXY_LANDING_PAGE_AUTO_OPTION))
+			return new RedirectView("/app/" + apps[0].getId());
+
 		Map<ProxySpec, String> appLogos = new HashMap<>();
 		map.put("appLogos", appLogos);