BREAKING CHANGE: SqlWaitForAG: Evaluate so that Availability Group is…

… available (#1636) - SqlWaitForAG - BREAKING CHANGE: Fix for issue (issue #1569) The resource now waits for the Availability Group to become Available. - Two parameters where added to test get and set resource at instance level.
dsccommunity · Nov 25, 2020 · ce78685 · ce78685
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -5,6 +5,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- WaitForAG
+  - BREAKING CHANGE: Fix for issue ([issue #1569](https://github.com/dsccommunity/SqlServerDsc/issues/1569))
+    The resource now waits for the Availability Group to become Available.
+  - Two parameters where added to test get and set resource at instance level.
 - SqlRole
   - Major overhaul of resource.
   - BREAKING CHANGE: Removed decision making from get-TargetResource; this

diff --git a/source/DSCResources/DSC_SqlWaitForAG/DSC_SqlWaitForAG.psm1 b/source/DSCResources/DSC_SqlWaitForAG/DSC_SqlWaitForAG.psm1
@@ -11,14 +11,21 @@ $script:localizedData = Get-LocalizedData -DefaultUICulture 'en-US'
         Returns the cluster role/group that is waiting to be created,
         along with the time and number of times to wait.
 
+    .PARAMETER ServerName
+        Hostname of the SQL Server to be configured.
+
+    .PARAMETER InstanceName
+        Name of the SQL instance to be configured.
+
     .PARAMETER Name
         Name of the cluster role/group to look for (normally the same as the
         Availability Group name).
 
     .PARAMETER RetryIntervalSec
         The interval, in seconds, to check for the presence of the cluster role/group.
         Default value is 20 seconds. When the cluster role/group has been found the
-        resource will wait for this amount of time once more before returning.
+        resource will check if the AG group exist. When the availability group has
+        been found the resource will also wait this amount of time before returning.
 
     .PARAMETER RetryCount
         Maximum number of retries until the resource will timeout and throw an error.
@@ -30,6 +37,16 @@ function Get-TargetResource
     [OutputType([System.Collections.Hashtable])]
     param
     (
+        [Parameter()]
+        [ValidateNotNullOrEmpty()]
+        [System.String]
+        $ServerName = $env:COMPUTERNAME,
+
+        [Parameter(Mandatory = $true)]
+        [ValidateNotNullOrEmpty()]
+        [System.String]
+        $InstanceName,
+
         [Parameter(Mandatory = $true)]
         [System.String]
         $Name,
@@ -49,14 +66,43 @@ function Get-TargetResource
 
     $clusterGroupFound = $false
 
+    # No ClusterName specified, so defaults to cluster on this node.
     $clusterGroup = Get-ClusterGroup -Name $Name -ErrorAction SilentlyContinue
+
     if ($null -ne $clusterGroup)
     {
         Write-Verbose -Message (
             $script:localizedData.FoundClusterGroup -f $Name
         )
 
-        $clusterGroupFound = $true
+        # Connect to the instance
+        $serverObject = Connect-SQL -ServerName $ServerName -InstanceName $InstanceName
+
+        if ($serverObject)
+        {
+            # Determine if HADR is enabled on the instance. If not, AG group can not exist.
+            if ($serverObject.IsHadrEnabled )
+            {
+                $availabilityGroup = $serverObject.AvailabilityGroups[$Name]
+
+                if ( $availabilityGroup )
+                {
+                    $clusterGroupFound = $true
+                }
+                else
+                {
+                    Write-Verbose -Message (
+                        $script:localizedData.AGNotFound -f $name, $InstanceName, $RetryIntervalSec
+                    )
+                }
+            }
+            else
+            {
+                Write-Verbose -Message (
+                    $script:localizedData.HadrNotEnabled -f $InstanceName
+                )
+            }
+        }
     }
     else
     {
@@ -66,6 +112,8 @@ function Get-TargetResource
     }
 
     return @{
+        ServerName       = $ServerName
+        InstanceName     = $InstanceName
         Name             = $Name
         RetryIntervalSec = $RetryIntervalSec
         RetryCount       = $RetryCount
@@ -77,14 +125,22 @@ function Get-TargetResource
     .SYNOPSIS
         Waits for a cluster role/group to be created
 
+    .PARAMETER ServerName
+        Hostname of the SQL Server to be configured.
+
+    .PARAMETER InstanceName
+        Name of the SQL instance to be configured.
+
     .PARAMETER Name
-        Name of the cluster role/group to look for (normally the same as the Availability
-        Group name).
+        Name of the cluster role/group to look for (normally the same as the
+        Availability Group name).
 
     .PARAMETER RetryIntervalSec
         The interval, in seconds, to check for the presence of the cluster role/group.
         Default value is 20 seconds. When the cluster role/group has been found the
-        resource will wait for this amount of time once more before returning.
+        resource will check if the AG group exist. When the availability group has
+        been found the resource will also wait this amount of time before returning.
+
 
     .PARAMETER RetryCount
         Maximum number of retries until the resource will timeout and throw an error.
@@ -95,6 +151,16 @@ function Set-TargetResource
     [CmdletBinding()]
     param
     (
+        [Parameter()]
+        [ValidateNotNullOrEmpty()]
+        [System.String]
+        $ServerName = $env:COMPUTERNAME,
+
+        [Parameter(Mandatory = $true)]
+        [ValidateNotNullOrEmpty()]
+        [System.String]
+        $InstanceName,
+
         [Parameter(Mandatory = $true)]
         [System.String]
         $Name,
@@ -113,6 +179,8 @@ function Set-TargetResource
     )
 
     $getTargetResourceParameters = @{
+        ServerName       = $ServerName
+        InstanceName     = $InstanceName
         Name             = $Name
         RetryIntervalSec = $RetryIntervalSec
         RetryCount       = $RetryCount
@@ -153,14 +221,22 @@ function Set-TargetResource
     .SYNOPSIS
         Tests if the cluster role/group has been created.
 
+    .PARAMETER ServerName
+        Hostname of the SQL Server to be configured.
+
+    .PARAMETER InstanceName
+        Name of the SQL instance to be configured.
+
     .PARAMETER Name
-        Name of the cluster role/group to look for (normally the same as the Availability
-        Group name).
+        Name of the cluster role/group to look for (normally the same as the
+        Availability Group name).
 
     .PARAMETER RetryIntervalSec
         The interval, in seconds, to check for the presence of the cluster role/group.
         Default value is 20 seconds. When the cluster role/group has been found the
-        resource will wait for this amount of time once more before returning.
+        resource will check if the AG group exist. When the availability group has
+        been found the resource will also wait this amount of time before returning.
+
 
     .PARAMETER RetryCount
         Maximum number of retries until the resource will timeout and throw an error.
@@ -172,6 +248,16 @@ function Test-TargetResource
     [OutputType([System.Boolean])]
     param
     (
+        [Parameter()]
+        [ValidateNotNullOrEmpty()]
+        [System.String]
+        $ServerName = $env:COMPUTERNAME,
+
+        [Parameter(Mandatory = $true)]
+        [ValidateNotNullOrEmpty()]
+        [System.String]
+        $InstanceName,
+
         [Parameter(Mandatory = $true)]
         [System.String]
         $Name,
@@ -190,6 +276,8 @@ function Test-TargetResource
     )
 
     $getTargetResourceParameters = @{
+        ServerName       = $ServerName
+        InstanceName     = $InstanceName
         Name             = $Name
         RetryIntervalSec = $RetryIntervalSec
         RetryCount       = $RetryCount

diff --git a/source/DSCResources/DSC_SqlWaitForAG/DSC_SqlWaitForAG.schema.mof b/source/DSCResources/DSC_SqlWaitForAG/DSC_SqlWaitForAG.schema.mof
@@ -1,6 +1,8 @@
 [ClassVersion("1.0.0.0"), FriendlyName("SqlWaitForAG")]
 class DSC_SqlWaitForAG : OMI_BaseResource
 {
+    [Key, Description("The name of the _SQL Server_ instance to be configured.")] String InstanceName;
+    [Write, Description("The host name of the _SQL Server_ to be configured. Default value is `$env:COMPUTERNAME`.")] String ServerName;
     [Key, Description("Name of the cluster role/group to look for (normally the same as the _Availability Group_ name).")] String Name;
     [Write, Description("The interval, in seconds, to check for the presence of the cluster role/group. Default value is `20` seconds. When the cluster role/group has been found the resource will wait for this amount of time once more before returning.")] UInt64 RetryIntervalSec;
     [Write, Description("Maximum number of retries until the resource will timeout and throw an error. Default values is `30` times.")] UInt32 RetryCount;

diff --git a/source/DSCResources/DSC_SqlWaitForAG/README.md b/source/DSCResources/DSC_SqlWaitForAG/README.md
@@ -1,8 +1,9 @@
 # Description
 
 The `SqlWaitForAG` DSC resource will wait for a cluster role/group to be
-created. This is used to wait for an Availability Group to create the
-cluster role/group in the cluster.
+created. When the cluster group is found it will wait for the availability group to become available. 
+When the availability group has been found the resource will wait the amount of time specified 
+in the parameter RetryIntervalSec before returning.
 
 ## Requirements
 
@@ -17,13 +18,4 @@ cluster role/group in the cluster.
 
 ## Known issues
 
-* This resource evaluates if the Windows Failover Cluster role/group
-  has been created. But the Windows Failover Cluster role/group is created
-  before the Availability Group is in a ready state. When the Windows Failover
-  Cluster role/group is found the resource will wait one more time
-  according to the value of `RetryIntervalSec` before returning. There is
-  currently no check to validate that the Availability Group was successfully
-  created and is in a ready state. A workaround is instead use [`WaitForAny`](https://docs.microsoft.com/en-us/powershell/scripting/dsc/reference/resources/windows/waitforanyresource?view=powershell-7)
-  resource. This is being tracked in [issue #1569](https://github.com/dsccommunity/SqlServerDsc/issues/1569).
-
 All issues are not listed here, see [here for all open issues](https://github.com/dsccommunity/SqlServerDsc/issues?q=is%3Aissue+is%3Aopen+in%3Atitle+SqlWaitForAG).
diff --git a/source/DSCResources/DSC_SqlWaitForAG/en-US/DSC_SqlWaitForAG.strings.psd1 b/source/DSCResources/DSC_SqlWaitForAG/en-US/DSC_SqlWaitForAG.strings.psd1
@@ -7,4 +7,6 @@ ConvertFrom-StringData @'
     RetryMessage = Will retry again after {0} seconds.
     FailedMessage = Did not find the cluster group '{0}' within the timeout period.
     TestingConfiguration = Determines the current state of the Always On Availability Group with the cluster group name '{0}'.
+    HadrNotEnabled = Hadr is not enabled on the sql server instance '{0}'.
+    AGNotFound = Availibility Group '{0}' not found on instance '{1}'. Waiting an other {2} seconds.
 '@
diff --git a/source/Examples/Resources/SqlWaitForAG/1-WaitForASingleClusterGroup.ps1 b/source/Examples/Resources/SqlWaitForAG/1-WaitForASingleClusterGroup.ps1
@@ -20,6 +20,7 @@ Configuration Example
             Name                 = 'AGTest1'
             RetryIntervalSec     = 20
             RetryCount           = 30
+            InstanceName         = 'MSSQLSERVER'
 
             PsDscRunAsCredential = $SqlAdministratorCredential
         }

diff --git a/source/Examples/Resources/SqlWaitForAG/2-WaitForMultipleClusterGroups.ps1 b/source/Examples/Resources/SqlWaitForAG/2-WaitForMultipleClusterGroups.ps1
@@ -20,6 +20,7 @@ Configuration Example
             Name                 = 'AGTest1'
             RetryIntervalSec     = 20
             RetryCount           = 30
+            InstanceName         = 'MSSQLSERVER'
 
             PsDscRunAsCredential = $SqlAdministratorCredential
         }
@@ -29,6 +30,7 @@ Configuration Example
             Name                 = 'AGTest2'
             RetryIntervalSec     = 20
             RetryCount           = 30
+            InstanceName         = 'MSSQLSERVER'
 
             PsDscRunAsCredential = $SqlAdministratorCredential
         }