functions/Install-DbaMaintenanceSolution.ps1

function Install-DbaMaintenanceSolution {
    <#
    .SYNOPSIS
        Download and Install SQL Server Maintenance Solution created by Ola Hallengren (https://ola.hallengren.com)
    .DESCRIPTION
        This script will download and install the latest version of SQL Server Maintenance Solution created by Ola Hallengren
     
    .PARAMETER SqlInstance
        The target SQL Server instance
     
    .PARAMETER SqlCredential
        Allows you to login to servers using SQL Logins as opposed to Windows Auth/Integrated/Trusted. To use:
        $scred = Get-Credential, then pass $scred object to the -SqlCredential parameter.
        To connect as a different Windows user, run PowerShell as that user.
    
    .PARAMETER Database
        The database where Ola Hallengren's solution will be installed. Defaults to master
     
    .PARAMETER BackupLocation
        Location of the backup root directory. If this is not supplied, the default backup directory will be used.
     
    .PARAMETER CleanupTime
        Time in hours, after which backup files are deleted
     
    .PARAMETER OutputFileDirectory
        Specify the output file directory
     
    .PARAMETER ReplaceExisting
        If the objects are already present in the chosen database, we drop and recreate them
  
    .PARAMETER LogToTable
        Log commands to a table
 
    .PARAMETER Solution
        You can choose to install the complete solution (All) or only one of: Backup / IntegrityCheck / IndexOptimize
 
    .PARAMETER InstallJobs
        Create SQL Agent Jobs
         
    .PARAMETER WhatIf
        Shows what would happen if the command were to run. No actions are actually performed.
 
    .PARAMETER Confirm
        Prompts you for confirmation before executing any changing operations within the command.
 
    .PARAMETER EnableException
        By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message.
        This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting.
        Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch.
         
    .NOTES
        Author: Viorel Ciucu, viorel.ciucu@gmail.com, cviorel.com
 
    .LINK
        http://dbatools.io/Install-DbaMaintenanceSolution
     
    .EXAMPLE
        Install-DbaMaintenanceSolution -SqlInstance RES14224 -Database DBA -CleanupTime 72
     
        Installs Ola Hallengren's Solution objects on RES14224 in the DBA database.
        Backups will default to the default Backup Directory.
        If the Maintenance Solution already exists, the script will be halted.
    
    .EXAMPLE
        Install-DbaMaintenanceSolution -SqlInstance RES14224 -Database DBA -ReplaceExisting -CleanupTime 72 -LogToTable -Solution "Backup" -BackupLocation "Z:\SQLBackup" -InstallJobs
         
    .EXAMPLE
        Install-DbaMaintenanceSolution -SqlInstance RES14224 -Database DBA -BackupLocation "Z:\SQLBackup" -CleanupTime 72
     
        This will create the Ola Hallengren's Solution objects. Existing objects are not affected in any way.
        
    .EXAMPLE
        Install-DbaMaintenanceSolution -SqlInstance RES14224 -Database DBA -BackupLocation "Z:\SQLBackup" -CleanupTime 72 -ReplaceExisting
        
        This will drop and then recreate the Ola Hallengren's Solution objects
        The cleanup script will drop and recreate:
            - TABLE [dbo].[CommandLog]
            - STORED PROCEDURE [dbo].[CommandExecute]
            - STORED PROCEDURE [dbo].[DatabaseBackup]
            - STORED PROCEDURE [dbo].[DatabaseIntegrityCheck]
            - STORED PROCEDURE [dbo].[IndexOptimize]
 
        The follwing SQL Agent jobs will be deleted:
            - 'Output File Cleanup'
            - 'IndexOptimize - USER_DATABASES'
            - 'sp_delete_backuphistory'
            - 'DatabaseBackup - USER_DATABASES - LOG'
            - 'DatabaseBackup - SYSTEM_DATABASES - FULL'
            - 'DatabaseBackup - USER_DATABASES - FULL'
            - 'sp_purge_jobhistory'
            - 'DatabaseIntegrityCheck - SYSTEM_DATABASES'
            - 'CommandLog Cleanup'
            - 'DatabaseIntegrityCheck - USER_DATABASES'
            - 'DatabaseBackup - USER_DATABASES - DIFF'
 
    #>

    
    
    [CmdletBinding(SupportsShouldProcess = $true, ConfirmImpact = "High")]
    param (
        [parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [Alias('ServerInstance', 'SqlServer')]
        [DbaInstanceParameter[]]$SqlInstance,
        [PSCredential]$SqlCredential,
        [object]$Database = "master",
        [string]$BackupLocation,
        [int]$CleanupTime,
        [string]$OutputFileDirectory,
        [switch]$ReplaceExisting,
        [switch]$LogToTable,
        [ValidateSet('All', 'Backup', 'IntegrityCheck', 'IndexOptimize')]
        [string]$Solution = 'All',
        [switch]$InstallJobs,
        [switch][Alias('Silent')]$EnableException
    )
    
    process {
        
        foreach ($instance in $SqlInstance) {
            try {
                Write-Message -Level Verbose -Message "Connecting to $instance"
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $SqlCredential
            }
            catch {
                Stop-Function -Message "Failure" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue
            }
            
            if ((Test-Bound -Parameter ReplaceExisting -Not)) {
                $procs = Get-DbaSqlModule -SqlInstance $server -Database $Database | Where-Object Name -in 'CommandExecute', 'DatabaseBackup', 'DatabaseIntegrityCheck', 'IndexOptimize'
                $table = Get-DbaTable -SqlInstance $server -Database $Database -Table CommandLog -IncludeSystemDBs  | where Database -eq $Database
                
                if ($null -ne $procs -or $null -ne $table) {
                    Stop-Function -Message "The Maintenance Solution already exists in $Database on $instance. Use -ReplaceExisting to automatically drop and recreate."
                    return
                }
            }
            
            if ((Test-Bound -Parameter BackupLocation -Not)) {
                $BackupLocation = (Get-DbaDefaultPath -SqlInstance $server).Backup
            }
            
            Write-Message -Level Output -Message "Ola Hallengren's solution will be installed on database: $Database"
            
            $db = $server.Databases[$Database]
            
            if ($InstallJobs -and $Solution -ne 'All') {
                Stop-Function -Message "To create SQL Agent jobs you need to use '-Solution All' and '-InstallJobs Create'"
                return
            }
            
            if ($ReplaceExisting -eq $true) {
                Write-Message -Level Verbose -Message "If Ola Hallengren's scripts are found, we will drop and recreate them!"
            }
            
            if ($CleanupTime -ne 0 -and $InstallJobs -eq $false) {
                Write-Message -Level Output -Message "CleanupTime $CleanupTime value will be ignored because you chose not to create SQL Agent Jobs"
            }
    
            # Required
            $required = @('CommandExecute.sql')
                    
            if ($LogToTable) {
                $required += 'CommandLog.sql'
            }
            
            if ($Solution -match 'Backup') {
                $required += 'DatabaseBackup.sql'
            }

            if ($Solution -match 'IntegrityCheck') {
                $required += 'DatabaseIntegrityCheck.sql'
            }
            
            if ($Solution -match 'IndexOptimize') {
                $required += 'IndexOptimize.sql'
            }
            
            if ($Solution -match 'All') {
                $required += 'MaintenanceSolution.sql'
            }
                                   
            $temp = ([System.IO.Path]::GetTempPath()).TrimEnd("\")
            $shell = New-Object -ComObject Shell.Application
            $zipfile = "$temp\ola.zip"
            
            # Start the download
            $url = "https://github.com/olahallengren/sql-server-maintenance-solution/archive/master.zip"
            try {
                $job = Start-BitsTransfer -Source $url -DisplayName 'Downloading SQL Server Maintenance Solution - https://ola.hallengren.com' -Destination $zipfile -ErrorAction Stop
            }
            catch {
                Stop-Function -Message "You need to re-run the script, there is a problem with the proxy or the download link has changed." -ErrorRecord $_
            }
            
            # Unblock if there's a block
            Unblock-File $zipfile -ErrorAction SilentlyContinue
            
            $path = "$temp\sql-server-maintenance-solution-master"
            
            # We don't like default parameters messed with so we start clean
            if ((Test-Path $path)) {
                Remove-Item -Path $temp\sql-server-maintenance-solution-master -Recurse -Force -ErrorAction SilentlyContinue
            }

            # internal if it doesn't exist
            Expand-Archive -Path $zipfile -DestinationPath $temp -Force
            Remove-Item -Path $zipfile          
            
            $listOfFiles = Get-ChildItem -Filter "*.sql" -Path $path | Select-Object -ExpandProperty FullName
            
            # In which database we install
            if ($Database -ne 'master') {
                $findDB = 'USE [master]'
                $replaceDB = 'USE [' + $Database + ']'
                foreach ($file in $listOfFiles) {
                    (Get-Content -Path $file -Raw).Replace($findDB, $replaceDB) | Set-Content -Path $file
                }
            }
            
            # Backup location
            if ($BackupLocation) {
                $findBKP = 'C:\Backup'
                $replaceBKP = $BackupLocation
                foreach ($file in $listOfFiles) {
                    (Get-Content -Path $file -Raw).Replace($findBKP, $replaceBKP) | Set-Content -Path $file
                }
            }
            
            # CleanupTime
            if ($CleanupTime -ne 0) {
                $findCleanupTime = 'SET @CleanupTime = NULL'
                $replaceCleanupTime = 'SET @CleanupTime = ' + $CleanupTime
                foreach ($file in $listOfFiles) {
                    (Get-Content -Path $file -Raw).Replace($findCleanupTime, $replaceCleanupTime) | Set-Content -Path $file
                }
            }
            
            # OutputFileDirectory
            if ($OutputFileDirectory.Length -gt 0) {
                $findOutputFileDirectory = 'SET @OutputFileDirectory = NULL'
                $replaceOutputFileDirectory = 'SET @OutputFileDirectory = N''' + $OutputFileDirectory + ''''
                foreach ($file in $listOfFiles) {
                    (Get-Content -Path $file -Raw).Replace($findOutputFileDirectory, $replaceOutputFileDirectory) | Set-Content -Path $file
                }
                
            }
            
            # LogToTable
            if (!$LogToTable) {
                $findLogToTable = "SET @LogToTable = 'Y'"
                $replaceLogToTable = "SET @LogToTable = 'N'"
                foreach ($file in $listOfFiles) {
                    (Get-Content -Path $file -Raw).Replace($findLogToTable, $replaceLogToTable) | Set-Content -Path $file
                }       
            }
            
            # Create Jobs
            if ($InstallJobs -eq $false) {
                $findCreateJobs = "SET @CreateJobs = 'Y'"
                $replaceCreateJobs = "SET @CreateJobs = 'N'"
                foreach ($file in $listOfFiles) {
                    (Get-Content -Path $file -Raw).Replace($findCreateJobs, $replaceCreateJobs) | Set-Content -Path $file
                }
            }
                   
            $CleanupQuery = $null
            if ($ReplaceExisting) {
                [string]$CleanupQuery = $("
                            IF OBJECT_ID('[dbo].[CommandLog]', 'U') IS NOT NULL
                                DROP TABLE [dbo].[CommandLog];
                            IF OBJECT_ID('[dbo].[CommandExecute]', 'P') IS NOT NULL
                                DROP PROCEDURE [dbo].[CommandExecute];
                            IF OBJECT_ID('[dbo].[DatabaseBackup]', 'P') IS NOT NULL
                                DROP PROCEDURE [dbo].[DatabaseBackup];
                            IF OBJECT_ID('[dbo].[DatabaseIntegrityCheck]', 'P') IS NOT NULL
                                DROP PROCEDURE [dbo].[DatabaseIntegrityCheck];
                            IF OBJECT_ID('[dbo].[IndexOptimize]', 'P') IS NOT NULL
                                DROP PROCEDURE [dbo].[IndexOptimize];
                            "
)
                
                Write-Message -Level Output -Message "Dropping objects created by Ola's Maintenance Solution"
                $null = $db.Query($CleanupQuery)
                                
                # Remove Ola's Jobs
                if ($InstallJobs -and $ReplaceExisting) {
                    Write-Message -Level Output -Message "Removing existing SQL Agent Jobs created by Ola's Maintenance Solution"
                    $jobs = Get-DbaAgentJob -SqlInstance $server | Where-Object Description -match "hallengren"
                    if ($jobs) {
                        $jobs | foreach { Remove-DbaAgentJob -SqlInstance $instance -Job $_.name }
                    }
                }   
            }
            
            try {
                Write-Message -Level Output -Message "Installing on server $SqlInstance, database $Database"
                
                foreach ($file in $listOfFiles) {
                    $shortFileName = Split-Path $file -Leaf
                    if ($required.Contains($shortFileName)) {
                        Write-Message -Level Output -Message "Installing $file"
                        $sql = [IO.File]::ReadAllText($file)
                        try {
                            foreach ($query in ($sql -Split "\nGO\b")) {
                                $null = $db.Query($query)
                            }
                        }
                        catch {
                            Stop-Function -Message "Could not execute $file in $Database on $instance" -ErrorRecord $_ -Target $db -Continue
                        }
                    }
                }
            }
            catch {
                Stop-Function -Message "Could not execute $file in $Database on $instance" -ErrorRecord $_ -Target $db -Continue
            }
        }
        
        if ((Test-Path $path)) {
            Remove-Item -Path $temp\sql-server-maintenance-solution-master -Recurse -Force -ErrorAction SilentlyContinue
        }
        Write-Message -Level Output -Message "Installation complete"
    }
}