SqlDatabase: Support Changing Snapshot Isolation

CHANGELOG.md

@@ -23,6 +23,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - SqlReplication
   - The resource are now using the helper function `Get-SqlInstanceMajorVersion`
     ([issue #1408](https://github.com/dsccommunity/SqlServerDsc/issues/1408)).
+- SqlDatabase
+  - Support enabling or disabling snapshot isolation
+    ([issue #845](https://github.com/dsccommunity/SqlServerDsc/issues/845)).
 
 ### Fixed
 - SqlDatabaseRole

source/DSCResources/DSC_SqlDatabase/DSC_SqlDatabase.psm1

@@ -74,6 +74,7 @@ function Get-TargetResource
         CompatibilityLevel = $null
         RecoveryModel      = $null
         OwnerName          = $null
+        SnapshotIsolation  = $null
     }
 
     $sqlServerObject = Connect-SQL -ServerName $ServerName -InstanceName $InstanceName
@@ -90,6 +91,7 @@ function Get-TargetResource
             $returnValue['CompatibilityLevel'] = $sqlDatabaseObject.CompatibilityLevel
             $returnValue['RecoveryModel'] = $sqlDatabaseObject.RecoveryModel
             $returnValue['OwnerName'] = $sqlDatabaseObject.Owner
+            $returnValue['SnapshotIsolation'] = $sqlDatabaseObject.SnapshotIsolationState -eq 'Enabled'
 
             Write-Verbose -Message (
                 $script:localizedData.DatabasePresent -f $Name
@@ -137,6 +139,9 @@ function Get-TargetResource
 
     .PARAMETER OwnerName
         Specifies the name of the login that should be the owner of the database.
+
+    .PARAMETER SnapshotIsolation
+        Specifics whether snapshot isolation should be enabled for the new database.
 #>
 function Set-TargetResource
 {
@@ -181,7 +186,11 @@ function Set-TargetResource
 
         [Parameter()]
         [System.String]
-        $OwnerName
+        $OwnerName,
+
+        [Parameter()]
+        [System.Boolean]
+        $SnapshotIsolation
     )
 
     $sqlServerObject = Connect-SQL -ServerName $ServerName -InstanceName $InstanceName
@@ -275,6 +284,24 @@ function Set-TargetResource
                     $wasUpdate = $true
                 }
 
+                if ($PSBoundParameters.ContainsKey('SnapshotIsolation'))
+                {
+                    Write-Verbose -Message (
+                        $script:localizedData.UpdatingSnapshotIsolation -f $SnapshotIsolation
+                    )
+
+                    try
+                    {
+                        $sqlDatabaseObject.SetSnapshotIsolation($SnapshotIsolation)
+                    }
+                    catch
+                    {
+                        $errorMessage = $script:localizedData.FailedToUpdateSnapshotIsolation -f $SnapshotIsolation, $Name
+
+                        New-InvalidOperationException -Message $errorMessage -ErrorRecord $_
+                    }
+                }
+
                 try
                 {
                     if ($wasUpdate)
@@ -438,7 +465,11 @@ function Test-TargetResource
 
         [Parameter()]
         [System.String]
-        $OwnerName
+        $OwnerName,
+
+        [Parameter()]
+        [System.Boolean]
+        $SnapshotIsolation
     )
 
     Write-Verbose -Message (
@@ -516,6 +547,15 @@ function Test-TargetResource
 
                     $isDatabaseInDesiredState = $false
                 }
+
+                if ($PSBoundParameters.ContainsKey('SnapshotIsolation') -and $getTargetResourceResult.SnapshotIsolation -ne $SnapshotIsolation)
+                {
+                    Write-Verbose -Message (
+                        $script:localizedData.SnapshotIsolationWrong -f $Name, $getTargetResourceResult.SnapshotIsolation, $SnapshotIsolation
+                    )
+
+                    $isDatabaseInDesiredState = $false
+                }
             }
         }
     }

source/DSCResources/DSC_SqlDatabase/DSC_SqlDatabase.schema.mof

@@ -9,4 +9,5 @@ class DSC_SqlDatabase : OMI_BaseResource
     [Write, Description("Specifies the version of the _SQL Database Compatibility Level_ to use for the specified database."), ValueMap{"Version80","Version90","Version100","Version110","Version120","Version130","Version140","Version150"}, Values{"Version80","Version90","Version100","Version110","Version120","Version130","Version140","Version150"}] String CompatibilityLevel;
     [Write, Description("The recovery model for the specified database."), ValueMap{"Simple","Full","BulkLogged"}, Values{"Simple","Full","BulkLogged"}] String RecoveryModel;
     [Write, Description("Specifies the name of the login that should be the owner of the database.")] String OwnerName;
+    [Write, Description("Enables snapshot isolation for the specified database.")] Boolean SnapshotIsolation;
 };

source/DSCResources/DSC_SqlDatabase/en-US/DSC_SqlDatabase.strings.psd1

@@ -22,4 +22,7 @@ ConvertFrom-StringData @'
     OwnerNameWrong = The database '{0}' exist and has the owner '{1}', but expected it to have the owner '{2}'.
     UpdatingOwner = Changing the database owner to '{0}'.
     FailedToUpdateOwner = Failed changing to owner to '{0}' for the database '{1}'.
+    UpdatingSnapshotIsolation = Updating snapshot isolation to '{0}'.
+    FailedToUpdateSnapshotIsolation = Failed changing snapshot isolation to '{0}' for the database '{1}'.
+    SnapshotIsolationWrong = The database '{0}' exists and has snapshot isolation set to '{1}', but expected it to have snapshot isolation set to '{2}'.
 '@

tests/Integration/DSC_SqlDatabase.Integration.Tests.ps1

@@ -287,6 +287,56 @@ try
             }
         }
 
+        $configurationName = "$($script:dscResourceName)_AddDatabase6_Config"
+
+        Context ('When using configuration {0}' -f $configurationName) {
+            It 'Should compile and apply the MOF without throwing' {
+                {
+                    $configurationParameters = @{
+                        OutputPath           = $TestDrive
+                        # The variable $ConfigurationData was dot-sourced above.
+                        ConfigurationData    = $ConfigurationData
+                    }
+
+                    & $configurationName @configurationParameters
+
+                    $startDscConfigurationParameters = @{
+                        Path         = $TestDrive
+                        ComputerName = 'localhost'
+                        Wait         = $true
+                        Verbose      = $true
+                        Force        = $true
+                        ErrorAction  = 'Stop'
+                    }
+
+                    Start-DscConfiguration @startDscConfigurationParameters
+                } | Should -Not -Throw
+            }
+
+            It 'Should be able to call Get-DscConfiguration without throwing' {
+                {
+                    $script:currentConfiguration = Get-DscConfiguration -Verbose -ErrorAction Stop
+                } | Should -Not -Throw
+            }
+
+            It 'Should have set the resource and all the parameters should match' {
+                $resourceCurrentState = $script:currentConfiguration | Where-Object -FilterScript {
+                    $_.ConfigurationName -eq $configurationName `
+                    -and $_.ResourceId -eq $resourceId
+                }
+
+                $resourceCurrentState.Ensure | Should -Be 'Present'
+                $resourceCurrentState.Name | Should -Be $ConfigurationData.AllNodes.DatabaseName6
+                $resourceCurrentState.ServerName | Should -Be $ConfigurationData.AllNodes.ServerName
+                $resourceCurrentState.InstanceName  | Should -Be $ConfigurationData.AllNodes.InstanceName
+                $resourceCurrentState.SnapshotIsolation | Should -Be $ConfigurationData.AllNodes.SnapshotIsolation
+            }
+
+            It 'Should return $true when Test-DscConfiguration is run' {
+                Test-DscConfiguration -Verbose | Should -Be 'True'
+            }
+        }
+
         $configurationName = "$($script:dscResourceName)_RemoveDatabase2_Config"
 
         Context ('When using configuration {0}' -f $configurationName) {
@@ -333,6 +383,7 @@ try
                 $resourceCurrentState.OwnerName | Should -BeNullOrEmpty
                 $resourceCurrentState.RecoveryModel | Should -BeNullOrEmpty
                 $resourceCurrentState.CompatibilityLevel | Should -BeNullOrEmpty
+                $resourceCurrentState.SnapshotIsolation | Should -BeNullOrEmpty
             }
 
             It 'Should return $true when Test-DscConfiguration is run' {

tests/Integration/DSC_SqlDatabase.config.ps1

@@ -30,11 +30,13 @@ else
                 DatabaseName3      = 'Database3'
                 DatabaseName4      = 'Database4'
                 DatabaseName5      = 'Database5'
+                DatabaseName6      = 'Database6'
 
                 Collation          = 'SQL_Latin1_General_Pref_CP850_CI_AS'
                 CompatibilityLevel = 'Version120'
                 RecoveryModel      = 'Simple'
                 OwnerName          = 'sa'
+                SnapshotIsolation  = $true
             }
         )
     }
@@ -164,6 +166,31 @@ Configuration DSC_SqlDatabase_AddDatabase5_Config
     }
 }
 
+<#
+    .SYNOPSIS
+        Creates a database with a specific snapshot isolation.
+#>
+Configuration DSC_SqlDatabase_AddDatabase6_Config
+{
+    Import-DscResource -ModuleName 'SqlServerDsc'
+
+    node $AllNodes.NodeName
+    {
+        SqlDatabase 'Integration_Test'
+        {
+            Ensure               = 'Present'
+            ServerName           = $Node.ServerName
+            InstanceName         = $Node.InstanceName
+            Name                 = $Node.DatabaseName6
+            SnapshotIsolation    = $Node.SnapshotIsolation
+
+            PsDscRunAsCredential = New-Object `
+                -TypeName System.Management.Automation.PSCredential `
+                -ArgumentList @($Node.Username, (ConvertTo-SecureString -String $Node.Password -AsPlainText -Force))
+        }
+    }
+}
+
 <#
     .SYNOPSIS
         Removes the second databases that was created.