From 3f7e593bc2ee7c3b48af9506c3e95b129dedb0db Mon Sep 17 00:00:00 2001
From: Shannon <sdeminick@gmail.com>
Date: Tue, 20 Dec 2016 14:10:06 +1100
Subject: [PATCH] U4-9302 Add logging of non security related connection string
 details when the connection fails

---
 src/Umbraco.Core/DatabaseContext.cs           | 29 +++++++++++++--
 .../Persistence/DbConnectionExtensions.cs     | 37 ++++++++++++++++++-
 2 files changed, 61 insertions(+), 5 deletions(-)

diff --git a/src/Umbraco.Core/DatabaseContext.cs b/src/Umbraco.Core/DatabaseContext.cs
index 585f1d51cf..a6d6ca9e6e 100644
--- a/src/Umbraco.Core/DatabaseContext.cs
+++ b/src/Umbraco.Core/DatabaseContext.cs
@@ -34,6 +34,12 @@ namespace Umbraco.Core
         private string _connectionString;
         private string _providerName;
         private DatabaseSchemaResult _result;
+        private DateTime? _connectionLastChecked = null;
+
+        /// <summary>
+        /// The number of minutes to throttle the checks to CanConnect
+        /// </summary>
+        private const int ConnectionCheckMinutes = 1;
 
         [Obsolete("Use the constructor specifying all dependencies instead")]
         public DatabaseContext(IDatabaseFactory factory)
@@ -110,13 +116,28 @@ namespace Umbraco.Core
         {
             get
             {
-                if (IsDatabaseConfigured == false) return false;
-                var canConnect = DbConnectionExtensions.IsConnectionAvailable(ConnectionString, DatabaseProvider);
-                LogHelper.Info<DatabaseContext>("CanConnect = " + canConnect);
-                return canConnect;
+                if (IsDatabaseConfigured == false)
+                    return false;
+
+                //Don't check again if the timeout period hasn't elapsed
+                //this ensures we don't keep checking the connection too many times in a row like during startup.
+                //Do check if the _connectionLastChecked is null which means we're just initializing or it could 
+                //not connect last time it was checked.
+                if ((_connectionLastChecked.HasValue && (DateTime.Now - _connectionLastChecked.Value).TotalMinutes > ConnectionCheckMinutes)
+                    || _connectionLastChecked.HasValue == false)
+                {
+                    var canConnect = DbConnectionExtensions.IsConnectionAvailable(ConnectionString, DatabaseProvider);
+                    LogHelper.Info<DatabaseContext>("CanConnect = " + canConnect);
+
+                    _connectionLastChecked = canConnect == false ? null : (DateTime?) DateTime.Now;
+                    return canConnect;
+                }
+
+                return _connectionLastChecked.HasValue;
             }
         }
 
+
         /// <summary>
         /// Gets the configured umbraco db connection string.
         /// </summary>
diff --git a/src/Umbraco.Core/Persistence/DbConnectionExtensions.cs b/src/Umbraco.Core/Persistence/DbConnectionExtensions.cs
index c0c7b2a777..86072c45d5 100644
--- a/src/Umbraco.Core/Persistence/DbConnectionExtensions.cs
+++ b/src/Umbraco.Core/Persistence/DbConnectionExtensions.cs
@@ -4,9 +4,11 @@ using System.Configuration;
 using System.Data;
 using System.Data.Common;
 using System.Data.SqlClient;
+using System.Data.SqlServerCe;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using MySql.Data.MySqlClient;
 using Umbraco.Core.Logging; 
 
 namespace Umbraco.Core.Persistence
@@ -69,6 +71,38 @@ namespace Umbraco.Core.Persistence
             }
         }
 
+        public static string GetConnStringExSecurityInfo(this IDbConnection connection)
+        {
+            try
+            {
+                if (connection is SqlConnection)
+                {
+                    var builder = new SqlConnectionStringBuilder(connection.ConnectionString);
+                    return string.Format("DataSource: {0}, InitialCatalog: {1}", builder.DataSource, builder.InitialCatalog);
+                }
+
+                if (connection is SqlCeConnection)
+                {
+                    var builder = new SqlCeConnectionStringBuilder(connection.ConnectionString);
+                    return string.Format("DataSource: {0}", builder.DataSource);
+                }
+
+                if (connection is MySqlConnection)
+                {
+                    var builder = new MySqlConnectionStringBuilder(connection.ConnectionString);
+                    return string.Format("Server: {0}, Database: {1}", builder.Server, builder.Database);
+                }
+            }
+            catch (Exception ex)
+            {
+                LogHelper.WarnWithException(typeof(DbConnectionExtensions),
+                    "Could not resolve connection string parameters", ex);
+                return "(Could not resolve)";
+            }
+
+            throw new ArgumentException(string.Format("The connection type {0} is not supported", connection.GetType()));
+        }
+
         public static bool IsAvailable(this IDbConnection connection)
         {
             try
@@ -79,7 +113,8 @@ namespace Umbraco.Core.Persistence
             catch (DbException exc)
             {
                 // Don't swallow this error, the exception is super handy for knowing "why" its not available
-                LogHelper.WarnWithException<IDbConnection>("Configured database is reporting as not being available!", exc);
+                LogHelper.WarnWithException(typeof(DbConnectionExtensions),
+                    "Configured database is reporting as not being available! {0}", exc, connection.GetConnStringExSecurityInfo);
                 return false;
             }