Using Pester with dbatools Test-DbaLastBackup

In previous posts I have shown how to use Test-DbaLastBackup from dbatools and how you can make use of the results. Today we will look at using  Pester with the results

Pester provides a framework for running unit tests to execute and validate PowerShell commands from within PowerShell. Pester consists of a simple set of functions that expose a testing domain-specific language (DSL) for isolating, running, evaluating and reporting the results of PowerShell commands.

we shall use it to validate our results. First we need to gather our results as we have seen before, In this example I have set the MaxMb to 5 so change that if you are playing along

Import-Module dbatools
$TestServer = 'SQL2016N1'
$Server = 'SQL2016N2'
$servers = 'SQL2016N1','SQL2016N2'
$Results = $servers.ForEach{Test-DbaLastBackup -SqlServer $_ -Destination $TestServer -MaxMB 5}
Then we need to write some Pester Tests. I tried to use Test Cases which are the correct method to iterate through collections as Mike Robbins shows here but Pester does not accept the type of object that is returned from this command for that. It’s ok though, because Pester is just PowerShell we can use a foreach loop.
In this scenario, we are testing for failures rather than when the backup test has skipped due to the file path not being a network share or the size being greater than our max size, so our checks are using the Should Not assertion. I have also added a test for the time the backup was taken.
Describe "Last Backup Test results - NOTE THIS IGNORES Skipped restores,DBCC and BackupFiles" {
foreach($result in $results)
{
It "$($Result.Database) on $($Result.SourceServer) File Should Exist" {
$Result.FileExists| Should Not Be 'False'
}
It "$($Result.Database) on $($Result.SourceServer) Restore should be Success" {
$Result.RestoreResult| Should Not Be 'False'
}
It "$($Result.Database) on $($Result.SourceServer) DBCC should be Success" {
$Result.DBCCResult| Should Not Be 'False'
}
It "$($Result.Database) on $($Result.SourceServer) Backup Should be less than a week old" {
$Result.BackupTaken| Should BeGreaterThan (Get-Date).AddDays(-7)
}
}
If we run that we get an output like this. Green is Good Red is Bad 🙂
01 - pester script.PNG
We can save the script to a file and use the Invoke-Pester to call it like this.
Invoke-Pester C:\temp\BackupPester.ps1
(Some Restore Frames removed for brevity)
02 -invoke pester.gif
invoke-Pester can output results to a file so we can output to XML which can be consumed by many things
$Date = Get-Date -Format ddMMyyyHHmmss
$tempFolder = 'c:\temp\BackupTests\'
Push-Location $tempFolder
$XML = $tempFolder + "BackupTestResults_$Date.xml"
$script = 'C:\temp\BackupPester.ps1'
Invoke-Pester -Script $Script -OutputFile $xml -OutputFormat NUnitXml
will provide an XML file like this
04 - XML output.PNG
We can also make use of the reportunit.exe from http://relevantcodes.com/ to create pretty HTML files from the XML files we created
This piece of code will download and extract the file if it does not exist in the directory
#download and extract ReportUnit.exe
$url = 'http://relevantcodes.com/Tools/ReportUnit/reportunit-1.2.zip'
$fullPath = Join-Path $tempFolder $url.Split("/")[-1]
$reportunit = $tempFolder + '\reportunit.exe'
if((Test-Path $reportunit) -eq $false)
{
(New-Object Net.WebClient).DownloadFile($url,$fullPath)
Expand-Archive -Path $fullPath -DestinationPath $tempFolder
}
and this will run it against the XML and open the file
##run reportunit against report.xml and display result in browser
$HTML = $tempFolder  + 'index.html'
& .\reportunit.exe $tempFolder
Invoke-Item $HTML
which will look  like
03 - pretty html file.gif
Happy Automating

NOTE – The major 1.0 release of dbatools due in the summer 2017 may have breaking changes which will stop the above code from working. There are also new commands coming which may replace this command. This blog post was written using dbatools version 0.8.942 You can check your version using

 Get-Module dbatools

and update it using an Administrator PowerShell session with

 Update-Module dbatools

You may find that you get no output from Update-Module as you have the latest version. If you have not installed the module from the PowerShell Gallery using

Install-Module dbatools

Then you can use

Update-dbatools

3 thoughts on “Using Pester with dbatools Test-DbaLastBackup

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