/WP7.1/BabelCam/C#/BabelCam.Web/WebRole.cs

// ----------------------------------------------------------------------------------

// Microsoft Developer & Platform Evangelism

// 

// Copyright (c) Microsoft Corporation. All rights reserved.

// 

// THIS CODE AND INFORMATION ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, 

// EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES 

// OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.

// ----------------------------------------------------------------------------------

// The example companies, organizations, products, domain names,

// e-mail addresses, logos, people, places, and events depicted

// herein are fictitious.  No association with any real company,

// organization, product, domain name, email address, logo, person,

// places, or events is intended or should be inferred.

// ----------------------------------------------------------------------------------



namespace Microsoft.Samples.BabelCam.Web

{

    using System;

    using System.Diagnostics;

    using System.Linq;

    using System.Security.Permissions;

    using System.Xml.Linq;

    using Microsoft.Samples.BabelCam.Infrastructure.Helpers;

    using Microsoft.Samples.BabelCam.Infrastructure.Models;

    using Microsoft.Samples.BabelCam.Web.Helpers;

    using Microsoft.Samples.BabelCam.Web.Models;

    using Microsoft.Samples.BabelCam.Web.Services;

    using Microsoft.WindowsAzure;

    using Microsoft.WindowsAzure.Diagnostics;

    using Microsoft.WindowsAzure.ServiceRuntime;

    using Microsoft.WindowsAzure.StorageClient;



    public class WebRole : RoleEntryPoint

    {

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2122:DoNotIndirectlyExposeMethodsWithLinkDemands", Justification = "This method initializes the Web role.")]

        public override bool OnStart()

        {

            DiagnosticMonitor.Start("Microsoft.WindowsAzure.Plugins.Diagnostics.ConnectionString");



            // For information on handling configuration changes

            // see the MSDN topic at http://go.microsoft.com/fwlink/?LinkId=166357.

            RoleEnvironment.Changing += this.RoleEnvironmentChanging;



            // This code sets up a handler to update CloudStorageAccount instances when their corresponding

            // configuration settings change in the service configuration file.

            CloudStorageAccount.SetConfigurationSettingPublisher((configName, configSetter) =>

            {

                // Provide the configSetter with the initial value

                configSetter(RoleEnvironment.GetConfigurationSettingValue(configName));



                RoleEnvironment.Changed += (sender, arg) =>

                {

                    if (arg.Changes.OfType<RoleEnvironmentConfigurationSettingChange>()

                        .Any((change) => (change.ConfigurationSettingName == configName)))

                    {

                        // The corresponding configuration setting has changed, propagate the value

                        if (!configSetter(RoleEnvironment.GetConfigurationSettingValue(configName)))

                        {

                            // In this case, the change to the storage account credentials in the

                            // service configuration is significant enough that the role needs to be

                            // recycled in order to use the latest settings. (for example, the 

                            // endpoint has changed)

                            RoleEnvironment.RequestRecycle();

                        }

                    }

                };

            });



            // If no valid WIF settings are found in the Web Role configuration, then the Web Role shouldn't start

            if (!UpdateWifSettings())

            {

                return false;

            }



            return base.OnStart();

        }



        [EnvironmentPermission(SecurityAction.LinkDemand)]

        private static bool UpdateWifSettings()

        {

            using (var server = new Microsoft.Web.Administration.ServerManager())

            {

                var siteNameFromServiceModel = "Web";

                var siteName = string.Format(System.Globalization.CultureInfo.InvariantCulture, "{0}_{1}", RoleEnvironment.CurrentRoleInstance.Id, siteNameFromServiceModel);



                var configFilePath = string.Format(System.Globalization.CultureInfo.InvariantCulture, @"{0}\Web.config", server.Sites[siteName].Applications[0].VirtualDirectories[0].PhysicalPath);

                var xml = XElement.Load(configFilePath);

                var identityModelService = xml.Element("microsoft.identityModel").Element("service");



                if (UpdateAttributeWithRoleSetting(identityModelService.Element("audienceUris").Element("add").Attribute("value"), "realm") &&

                    UpdateAttributeWithRoleSetting(identityModelService.Element("issuerTokenResolver").Element("serviceKeys").Element("add").Attribute("serviceName"), "realm") &&

                    UpdateAttributeWithRoleSetting(identityModelService.Element("issuerTokenResolver").Element("serviceKeys").Element("add").Attribute("serviceKey"), "serviceKey") &&

                    UpdateAttributeWithRoleSetting(identityModelService.Element("issuerNameRegistry").Element("trustedIssuers").Element("add").Attribute("issuerIdentifier"), "trustedIssuersIdentifier") &&

                    UpdateAttributeWithRoleSetting(identityModelService.Element("issuerNameRegistry").Element("trustedIssuers").Element("add").Attribute("name"), "trustedIssuerName"))

                {

                    xml.Save(configFilePath);

                    return true;

                }



                return false;

            }

        }



        private static bool UpdateAttributeWithRoleSetting(XAttribute attribute, string settingName)

        {

            var settingValue = ConfigReader.GetConfigValue(settingName, false);

            if (!string.IsNullOrEmpty(settingValue))

            {

                attribute.Value = settingValue;

            }

            else if (string.IsNullOrEmpty(attribute.Value))

            {

                return false;

            }



            return true;

        }



        private void RoleEnvironmentChanging(object sender, RoleEnvironmentChangingEventArgs e)

        {

            // If a configuration setting is changing

            if (e.Changes.Any(change => change is RoleEnvironmentConfigurationSettingChange))

            {

                // Set e.Cancel to true to restart this role instance

                e.Cancel = true;

            }

        }

    }

}