Health Check

The Settings section of the Umbraco backoffice holds a dashboard named "Health Check". It is a handy list of checks to see if your Umbraco installation is configured according to best practices. It's possible to add your custom built health checks. This feature has been available since Umbraco version 7.5.

For inspiration when building your own checks you can look at the checks we've built into Umbraco. Some examples will follow in this document.

Built-in checks

Umbraco comes with the following checks by default:

• Category Configuration
  • Macro errors (id: D0F7599E-9B2A-4D9E-9883-81C7EDC5616F) - checks that the errors are set to inline so that pages that error will still load (and shows a small error message)
  • Notification Email Settings (id: 3E2F7B14-4B41-452B-9A30-E67FBC8E1206) - checks that the "from" email address used for email notifications has been changed from its default value
  • Try Skip IIS Custom Errors (id: 046A066C-4FB2-4937-B931-069964E16C66) - in IIS 7.5 and higher this should be set to true
• Category Data Integrity
  • Database data integrity check (id: 73DD0C1C-E0CA-4C31-9564-1DCA509788AF) - checks for various data integrity issues in the Umbraco database
• Category Live environment
  • Custom errors (id: 4090C0A1-2C52-4124-92DD-F028FD066A64) - should be set to RemoteOnly or On on your live site
  • Trace mode (id: 9BED6EF4-A7F3-457A-8935-B64E9AA8BAB3) - should be set to enabled="false" on your live site
  • Debug compilation mode (id: 61214FF3-FC57-4B31-B5CF-1D095C977D6D) - should be set to debug="false" on your live site
• Category Permissions
  • Folder & file permissions (id: 53DBA282-4A79-4B67-B958-B29EC40FCC23) - checks that folders and files that are either required or recommended to set with write permissions can be accessed
• Category Security
  • Click-Jacking Protection (id: ED0D7E40-971E-4BE8-AB6D-8CC5D0A6A5B0) - checks to see if a header or meta-tag is in place to indicate whether the site can be hosted in an IFRAME. Normally this is best set to deny permission for this to be done, to prevent what is known as click-jacking attacks
  • Content/MIME Sniffing Protection (id: 1CF27DB3-EFC0-41D7-A1BB-EA912064E071) - checks that your site contains a header used to protect against MIME sniffing vulnerabilities
  • Cookie hijacking and protocol downgrade attacks Protection (HSTS) (id: E2048C48-21C5-4BE1-A80B-8062162DF124) - checks if your HTTPS site contains the Strict-Transport-Security Header (HSTS). If not - adds with a default of 18 weeks
  • Cross-site scripting Protection (id: F4D2B02E-28C5-4999-8463-05759FA15C3A) - checks for the presence of the X-XSS-Protection-header
  • Excessive Headers (id: 92ABBAA2-0586-4089-8AE2-9A843439D577) - checks to ensure that various headers that can provide details about the technology used to build and host the website have been removed
  • HTTPS check (id: EB66BB3B-1BCD-4314-9531-9DA2C1D6D9A7) - to determine if the current site is running on a secure connection
  • UseHttps check - when the site is running on HTTPS, Umbraco.Core.UseHttps needs to be enabled to secure the backoffice. The setting can be found under appSettings in the web.config file
• Category Services
  • SMTP settings (id: 1B5D221B-CE99-4193-97CB-5F3261EC73DF) - checks that an SMTP server is configured and is accepting requests for sending emails

Each check returns a message indicating whether or not the issue in question has been found on the website installation. This could be an error that should be fixed, or a warning you should be aware of.

Some of them can also be rectified via the dashboard, by clicking the Fix button and in some cases providing some required information. These changes usually involve writing to configuration files that will often trigger a restart of the website.

Configuring and scheduling checks

As well as viewing the results of health checks via the Settings section dashboard, you can set up the checks to be run on a schedule and be notified of the results by email. It's also possible to disable certain checks if they aren't applicable in your environment.

For more on this see the Reference > Config > Health checks page.

Custom checks

You can build your own health checks. There are two types of health checks you can build: configuration checks and general checks.

Each health check is a class that needs to have a HealthCheck attribute. This attribute has a few things you need to fill in:

• GUID - a unique ID that you've generated for this specific check
• Name - give it a short name so people know what the check is for
• Description - describes what the check does in detail
• Group - this is the category for the check if you use an existing group name (like "Configuration") the check will be added in that category, otherwise a new category will appear in the dashboard

Configuration checks

These are small checks that take an XPath query and confirm that the value that's expected is there. If the value is not correct, clicking the "Rectify" button will set the recommended value.

• A configuration check needs to inherit from Umbraco.Web.HealthCheck.Checks.Config.AbstractConfigCheck
• A configuration check needs the HealthCheck attribute as noted at the start of this document
• FilePath is the relative path to which config file you want to check
• XPath is the query you want to execute to find the configuration value you want to verify
• ValueComparisonType can either be ValueComparisonType.ShouldEqual or ValueComparisonType.ShouldNotEqual
• Values is a list of values that are available for this configuration item - in this example it can be RemoteOnly or On, they're both acceptable for a live site.
  • For checks using the ShouldEqual comparison method, make sure to set one of these values to IsRecommended = true - when the "Fix" button is pressed, the recommended value will be stored
  • Where ShouldNotEqual is used the fix will require the user to provide the correct setting
• CheckSuccessMessage, CheckErrorMessage and RectifySuccessMessage are the messages returned to the user
  • It is highly recommended to use the LocalizedTextService so these can be localized. You can add the text in ~/Config/Lang/en-US.user.xml (or whatever language you like)
  • Don't add the translations to ~/Umbraco/Config/Lang files, the correct location is ~/Config/Lang/*-*.user.xml

An example check:

using System.Collections.Generic;
using System.Linq;
using Umbraco.Core.Services;

namespace Umbraco.Web.HealthCheck.Checks.Config
{
    [HealthCheck("D0F7599E-9B2A-4D9E-9883-81C7EDC5616F", "Macro errors",
        Description = "Checks to make sure macro errors are not set to throw a YSOD (yellow screen of death), which would prevent certain or all pages from loading completely.",
        Group = "Configuration")]
    public class MacroErrorsCheck : AbstractConfigCheck
    {
        public MacroErrorsCheck(ILocalizedTextService textService) : base(textService) { }

        public override string FilePath
        {
            get { return "~/Config/umbracoSettings.config"; }
        }

        public override string XPath
        {
            get { return "/settings/content/MacroErrors"; }
        }

        public override ValueComparisonType ValueComparisonType
        {
            get { return ValueComparisonType.ShouldEqual; }
        }

        public override IEnumerable<AcceptableConfiguration> Values
        {
            get
            {
                var values = new List<AcceptableConfiguration>
                {
                    new AcceptableConfiguration
                    {
                        IsRecommended = true,
                        Value = "inline"
                    },
                    new AcceptableConfiguration
                    {
                        IsRecommended = false,
                        Value = "silent"
                    }
                };

                return values;
            }
        }

        public override string CheckSuccessMessage
        {
            get
            {
                return TextService.Localize("healthcheck/macroErrorModeCheckSuccessMessage",
                    new[] { CurrentValue, Values.First(v => v.IsRecommended).Value });
            }
        }

        public override string CheckErrorMessage
        {
            get
            {
                return TextService.Localize("healthcheck/macroErrorModeCheckErrorMessage",
                    new[] { CurrentValue, Values.First(v => v.IsRecommended).Value });
            }
        }

        public override string RectifySuccessMessage
        {
            get
            {
                return TextService.Localize("healthcheck/macroErrorModeCheckRectifySuccessMessage",
                    new[] { Values.First(v => v.IsRecommended).Value });
            }
        }
    }
}

General checks

This can be anything you can think of, the results and the rectify action are completely under your control.

• A general check needs to inherit from Umbraco.Web.HealthCheck
• A general check needs the HealthCheck attribute as noted at the start of this document
• All checks run when the dashboard is loaded, this means that the GetStatus() method gets executed
  • You can return multiple status checks from GetStatus()
• A status check returns a HealthCheckStatus
  • If a HealthCheckStatus has a HealthCheckAction defined then the "Fix" button will perform that action once clicked
  • Sometimes, the button to fix something should not be called "Fix", change the Name property of a HealthCheckAction to provide a better name
  • HealthCheckAction has a Description property so that you can provide information on what clicking the "Rectify" button will do (or provide links to documentation, for example)
  • HealthCheckStatus has a few result levels:
    • StatusResultType.Success
    • StatusResultType.Error
    • StatusResultType.Warning
    • StatusResultType.Info
  • A HealthCheckAction needs to provide an alias for an action that can be picked up in the ExecuteAction method
• It is highly recommended to use the LocalizedTextService so text can be localized. You can add the text in ~/Config/Lang/en-US.user.xml (or whatever language you like)
• Don't add the translations to ~/Umbraco/Config/Lang files, the correct location is ~/Config/Lang/*-*.user.xml

An example check:

using System;
using System.Collections.Generic;
using System.IO;
using System.Web;
using System.Web.Hosting;
using Umbraco.Core.Composing;
using Umbraco.Core.Services;
using Umbraco.Web.HealthCheck;

namespace Umbraco.Web.HealthCheck.Checks.SEO
{
    [HealthCheck("3A482719-3D90-4BC1-B9F8-910CD9CF5B32", "Robots.txt",
    Description = "Create a robots.txt file to block access to system folders.",
    Group = "SEO")]
    public class RobotsTxt : HealthCheck
    {
        private readonly ILocalizedTextService _textService;

        public RobotsTxt(ILocalizedTextService textService)
        {
            _textService = textService;
        }

        public override IEnumerable GetStatus()
        {
            return new[] { CheckForRobotsTxtFile() };
        }

        public override HealthCheckStatus ExecuteAction(HealthCheckAction action)
        {
            switch (action.Alias)
            {
                case "addDefaultRobotsTxtFile":
                    return AddDefaultRobotsTxtFile();
                default:
                    throw new ArgumentOutOfRangeException();
            }
        }

        private HealthCheckStatus CheckForRobotsTxtFile()
        {
            var success = File.Exists(HttpContext.Current.Server.MapPath("~/robots.txt"));
            var message = success
                ? _textService.Localize("healthcheck/seoRobotsCheckSuccess")
                : _textService.Localize("healthcheck/seoRobotsCheckFailed");

            var actions = new List();

            if (success == false)
                actions.Add(new HealthCheckAction("addDefaultRobotsTxtFile", Id)
                // Override the "Rectify" button name and describe what this action will do
                {
                    Name = _textService.Localize("healthcheck/seoRobotsRectifyButtonName"),
                    Description = _textService.Localize("healthcheck/seoRobotsRectifyDescription")
                });

            return
                new HealthCheckStatus(message)
                {
                    ResultType = success ? StatusResultType.Success : StatusResultType.Error,
                    Actions = actions
                };
        }

        private HealthCheckStatus AddDefaultRobotsTxtFile()
        {
            var success = false;
            var message = string.Empty;
            
            const string content = 
                @"# robots.txt for Umbraco
                User-agent: *
                Disallow: /umbraco/";

            try
            {
                File.WriteAllText(HostingEnvironment.MapPath("~/robots.txt"), content);
                success = true;
            }
            catch (Exception exception)
            {
                Current.Logger.Error(typeof(RobotsTxt), exception, "Could not write robots.txt to the root of the site");
            }

            return
                new HealthCheckStatus(message)
                {
                    ResultType = success ? StatusResultType.Success : StatusResultType.Error,
                    Actions = new List()
                };
        }
    }
}

Custom health check notifications

Health check notifications can be scheduled to run periodically and notify you of the results. Included with Umbraco is a notification method to deliver the results via email. In a similar manner to how it's possible to create your own health checks, you can also create custom notification methods to send the message summarising the status of the health checks via other means. Again, for further details on implementing this, please refer the existing notification methods within the core code base.

Each notification method needs to implement the core interface IHealthCheckNotificationMethod and, for ease of creation, can inherit from the base class NotificationMethodBase, which itself implements the IHealthCheckNotificationMethod interface. There's one method to implement - SendAsync(HealthCheckResults results) - which is responsible for taking the results of the health checks and sending them via the mechanism of your choice.

The following example shows how the core method for sending notification via email is implemented:

using System;
using System.Net.Mail;
using System.Threading;
using System.Threading.Tasks;
using Umbraco.Core;
using Umbraco.Core.Composing;
using Umbraco.Core.Logging;
using Umbraco.Core.Services;

namespace Umbraco.Web.HealthCheck.NotificationMethods
{
    [HealthCheckNotificationMethod("email")]
    public class EmailNotificationMethod : NotificationMethodBase
    {
        private readonly ILocalizedTextService _textService;
        private readonly IRuntimeState _runtimeState;
        private readonly ILogger _logger;

        public EmailNotificationMethod(ILocalizedTextService textService, IRuntimeState runtimeState, ILogger logger)
        {
            var recipientEmail = Settings?["recipientEmail"]?.Value;
            if (string.IsNullOrWhiteSpace(recipientEmail))
            {
                Enabled = false;
                return;
            }

            RecipientEmail = recipientEmail;

            _textService = textService ?? throw new ArgumentNullException(nameof(textService));
            _runtimeState = runtimeState;
            _logger = logger;
        }

        public string RecipientEmail { get; }

        public override async Task SendAsync(HealthCheckResults results, CancellationToken token)
        {
            if (ShouldSend(results) == false)
            {
                return;
            }

            if (string.IsNullOrEmpty(RecipientEmail))
            {
                return;
            }

            var message = _textService.Localize("healthcheck/scheduledHealthCheckEmailBody", new[]
            {
                DateTime.Now.ToShortDateString(),
                DateTime.Now.ToShortTimeString(),
                results.ResultsAsHtml(Verbosity)
            });

            // Include the umbraco Application URL host in the message subject so that
            // you can identify the site that these results are for.
            var host = _runtimeState.ApplicationUrl;

            var subject = _textService.Localize("healthcheck/scheduledHealthCheckEmailSubject", new[] { host.ToString() });

            var mailSender = new EmailSender();
            using (var mailMessage = CreateMailMessage(subject, message))
            {
                await mailSender.SendAsync(mailMessage);
            }
        }

        private MailMessage CreateMailMessage(string subject, string message)
        {
            var to = Current.Configs.Settings().Content.NotificationEmailAddress;

            if (string.IsNullOrWhiteSpace(subject))
                subject = "Umbraco Health Check Status";

            return new MailMessage(to, RecipientEmail, subject, message)
            {
                IsBodyHtml = message.IsNullOrWhiteSpace() == false && message.Contains("<") && message.Contains("</")
            };
        }
    }
}

If custom configuration is required for a custom notification method, this can be placed in HealthChecks.config, with the alias XML attribute for the notificationMethod element matching that used on the class level attribute. Again, the following extract shows how the email notification method is configured:

<HealthChecks>
    <notificationSettings enabled="true" firstRunTime="" periodInHours="24">
    <notificationMethods>
        <notificationMethod alias="email" enabled="true" verbosity="Summary">
        <settings>
            <add key="recipientEmail" value="alerts@mywebsite.tld" />
        </settings>
        </notificationMethod>
    </notificationMethods>
    </notificationSettings>
</HealthChecks>