Implement #11776 for v9

src/Umbraco.Core/HealthChecks/Checks/Security/UmbracoApplicationUrlCheck.cs

@@ -0,0 +1,68 @@
+// Copyright (c) Umbraco.
+// See LICENSE for more details.
+
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Options;
+using Umbraco.Cms.Core.Configuration.Models;
+using Umbraco.Cms.Core.Services;
+using Umbraco.Extensions;
+
+namespace Umbraco.Cms.Core.HealthChecks.Checks.Security
+{
+    [HealthCheck(
+        "6708CA45-E96E-40B8-A40A-0607C1CA7F28",
+        "Application URL Configuration",
+        Description = "Checks if the Umbraco application URL is configured for your site.",
+        Group = "Security")]
+    public class UmbracoApplicationUrlCheck : HealthCheck
+    {
+        private readonly ILocalizedTextService _textService;
+        private readonly IOptionsMonitor<WebRoutingSettings> _webRoutingSettings;
+
+        public UmbracoApplicationUrlCheck(ILocalizedTextService textService, IOptionsMonitor<WebRoutingSettings> webRoutingSettings)
+        {
+            _textService = textService;
+            _webRoutingSettings = webRoutingSettings;
+        }
+
+        /// <summary>
+        /// Executes the action and returns its status
+        /// </summary>
+        public override HealthCheckStatus ExecuteAction(HealthCheckAction action) => throw new InvalidOperationException("UmbracoApplicationUrlCheck has no executable actions");
+
+        /// <summary>
+        /// Get the status for this health check
+        /// </summary>
+        public override Task<IEnumerable<HealthCheckStatus>> GetStatus() =>
+            Task.FromResult(CheckUmbracoApplicationUrl().Yield());
+
+        private HealthCheckStatus CheckUmbracoApplicationUrl()
+        {
+            var url = _webRoutingSettings.CurrentValue.UmbracoApplicationUrl;
+
+            string resultMessage;
+            StatusResultType resultType;
+            var success = false;
+
+            if (url.IsNullOrWhiteSpace())
+            {
+                resultMessage = _textService.Localize("healthcheck", "umbracoApplicationUrlCheckResultFalse");
+                resultType = StatusResultType.Warning;
+            }
+            else
+            {
+                resultMessage = _textService.Localize("healthcheck", "umbracoApplicationUrlCheckResultTrue", new[] { url });
+                resultType = StatusResultType.Success;
+                success = true;
+            }
+
+            return new HealthCheckStatus(resultMessage)
+            {
+                ResultType = resultType,
+                ReadMoreLink = success ? null : Constants.HealthChecks.DocumentationLinks.Security.UmbracoApplicationUrlCheck
+            };
+        }
+    }
+}

src/Umbraco.Web.UI/umbraco/config/lang/en.xml

@@ -2290,6 +2290,8 @@ To manage your website, simply open the Umbraco backoffice and start adding cont
     <!-- The following keys get these tokens passed in:
 	    0: Comma delimitted list of failed folder paths
   	-->
+    <key alias="umbracoApplicationUrlCheckResultTrue"><![CDATA[The appSetting 'Umbraco:CMS:WebRouting:UmbracoApplicationUrl' is set to <strong>%0%</strong>.]]></key>
+    <key alias="umbracoApplicationUrlCheckResultFalse">The appSetting 'Umbraco:CMS:WebRouting:UmbracoApplicationUrl' is not set.</key>
     <key alias="clickJackingCheckHeaderFound">
       <![CDATA[The header or meta-tag <strong>X-Frame-Options</strong> used to control whether a site can be IFRAMEd by another was found.]]></key>
     <key alias="clickJackingCheckHeaderNotFound">

src/Umbraco.Web.UI/umbraco/config/lang/en_us.xml

@@ -2372,6 +2372,8 @@ To manage your website, simply open the Umbraco backoffice and start adding cont
     <!-- The following keys get these tokens passed in:
 	    0: Comma delimitted list of failed folder paths
   	-->
+    <key alias="umbracoApplicationUrlCheckResultTrue"><![CDATA[The appSetting 'Umbraco:CMS:WebRouting:UmbracoApplicationUrl' is set to <strong>%0%</strong>.]]></key>
+    <key alias="umbracoApplicationUrlCheckResultFalse">The appSetting 'Umbraco:CMS:WebRouting:UmbracoApplicationUrl' is not set.</key>
     <key alias="clickJackingCheckHeaderFound">
       <![CDATA[The header or meta-tag <strong>X-Frame-Options</strong> used to control whether a site can be IFRAMEd by another was found.]]></key>
     <key alias="clickJackingCheckHeaderNotFound">