New-DbaFirewallRule - Stop blaming a disabled DAC for a cycled ERRORLOG (#10528)

Author: andreasjordan

public/New-DbaFirewallRule.ps1

@@ -428,7 +428,10 @@ function New-DbaFirewallRule {
                 }
 
                 if (-not $dacMessage) {
-                    Write-Message -Level Warning -Message "No information about the dedicated admin connection (DAC) found in ERRORLOG, cannot create firewall rule for DAC. Use 'Set-DbaSpConfigure -SqlInstance '$instance' -Name RemoteDacConnectionsEnabled -Value 1' to enable remote DAC and try again."
+                    # SQL Server writes this message when the instance starts, and we only read the
+                    # current ERRORLOG. A log that was cycled since the last start therefore looks
+                    # exactly like a disabled DAC, so we must not claim the DAC is disabled here.
+                    Write-Message -Level Warning -Message "No information about the dedicated admin connection (DAC) found in the current ERRORLOG, cannot create firewall rule for DAC. That message is only written when the instance starts, so it is missing if the ERRORLOG was cycled since then. If remote DAC is disabled on $instance, enable it with Set-DbaSpConfigure -Name RemoteDacConnectionsEnabled -Value 1 and restart the instance."
                 } elseif ($dacMessage -match 'locally') {
                     Write-Message -Level Verbose -Message "Dedicated admin connection is only listening locally, so no firewall rule is needed."
                 } else {

tests/New-DbaFirewallRule.Tests.ps1

@@ -151,7 +151,11 @@ Describe $CommandName -Tag IntegrationTests {
             $null = Remove-DbaFirewallRule -SqlInstance $TestConfig.InstanceSingle
 
             # Create firewall rules with default RuleType (Program)
-            $resultsNew = New-DbaFirewallRule -SqlInstance $TestConfig.InstanceSingle
+            # The rule for the DAC can only be created when the instance wrote the DAC port to the
+            # current ERRORLOG, which it only does when it starts. On an instance whose ERRORLOG was
+            # cycled since then the command warns instead, so the warning is silenced here. It says
+            # nothing about the command and a test run must not print warnings.
+            $resultsNew = New-DbaFirewallRule -SqlInstance $TestConfig.InstanceSingle -WarningAction SilentlyContinue
             $resultsGet = Get-DbaFirewallRule -SqlInstance $TestConfig.InstanceSingle
             $resultsRemoveBrowser = $resultsGet | Where-Object Type -eq "Browser" | Remove-DbaFirewallRule
             $resultsRemove = Remove-DbaFirewallRule -SqlInstance $TestConfig.InstanceSingle -Type AllInstance
@@ -228,7 +232,8 @@ Describe $CommandName -Tag IntegrationTests {
             $null = Remove-DbaFirewallRule -SqlInstance $TestConfig.InstanceSingle
 
             # Create firewall rules with RuleType Port
-            $resultsNewPort = New-DbaFirewallRule -SqlInstance $TestConfig.InstanceSingle -RuleType Port
+            # Same as above: without the DAC port in the current ERRORLOG the command warns.
+            $resultsNewPort = New-DbaFirewallRule -SqlInstance $TestConfig.InstanceSingle -RuleType Port -WarningAction SilentlyContinue
             $resultsGetPort = Get-DbaFirewallRule -SqlInstance $TestConfig.InstanceSingle
             $resultsRemovePort = Remove-DbaFirewallRule -SqlInstance $TestConfig.InstanceSingle -Type AllInstance