Azure DevOps Masking a.k.a “point, no click”

“[My] kids haven’t responded to my GDPR requests so I don’t think I’m legally allowed to tell them when dinner’s on the table.”
@mrdaveturner

Ah masking. You would have thought I’d be sick of it by now, no? No, fortunately now, more so than ever, I find myself answering question after question and tackling use-case after use-case. So when I was asked this week:

“Chris, is there a way for us to call Data Masker for SQL Server directly from Azure DevOps?”

I thought to myself, well that sounds easy enough… and it was! I know what you’re thinking, c’mon Chris, surely there is more to it? But no, it’s actually pretty straight forward!

I pointed them at the PowerShell module and cmdlets for SQL Provision and the Azure DevOps plugin to automate all of their Provisioning and Masking process, thinking all the while “pffft, they could have made this harder!” and then…

“No sorry Chris, is there a way for us to call JUST Data Masker for SQL Server directly from Azure DevOps?”

Ah! Now that’s an interesting one!

#1 Figure out where you want Data Masking to run in your process

This empty Azure deployment stage looks good enough for now! If you wanted to chain other processes either side of it, that’s cool too! Maybe you have your own provisioning process in place and you want to point Data Masker at it to sanitize it? Makes sense to me! For now I’m going to stick with a single agent job for simplicity.

#2 Figure out what is actually going to run Data Masker

Data Masker is a client install and as such will need to be installed on a *gasp* actual machine!

No but seriously, any server you have lying around, physical or VM will do the trick as long as it meets these requirements. Now this Server/VM will need to have an Azure DevOps agent on it already, which of course is the ideal candidate for being the “thing” that calls Data Masker – this could be the Staging/Non-Functional/Pre-Prod environment also of course, so you could copy down PROD and then immediately invoke masking.

#3 Call the command line from Azure DevOps

In your pipeline steps you can specify the calling of an executable on the machine where the agent resides. Fortunately Data Masker has a wonderful command line available that you can call, you can read all about it here: https://documentation.red-gate.com/dms/data-masker-help/general-topics/about-command-line-automation

The PARFILE you could of course dynamically replace with variables so that it only calls the relevant parameter file for that particular database as well, a nice benefit!

My PARFILE just simply looked like this:

It was calling a local Data Masker set “AzureFun” – now the thing to bear in mind is that Data Masker will run with the Windows authentication credentials that are being run as by the Azure DevOps agent, unless you specify otherwise. In this case because the Azure DevOps agent has the correct permissions to update the databases on this instance anyway I’m fine to use Windows Authentication:

Conclusion

It’s very easy to simply call the command line of Data Masker for SQL Server directly from Azure DevOps, does this same approach work from other CI/CD tools? If they can call executables on the target server then absolutely! So it’s very easily included in the process – you just have to think about where Data Masker is installed and what credentials you’re using for it!

Bonus Point – what about if it’s all Azure SQL Database?

You had to do it didn’t you, you had to say it!

“But Chris, now we know we can call this all from Azure DevOps, what if we wanted to mask and copy Azure SQL Databases into Dev/Test etc.?”

Well actually the good thing is, it’s also pretty similar! When you’re connecting Data Masker to an Azure SQL DB you only need to specify this in the connections in the controller. Again, authentication will likely have to be SQL Auth at this point, and you need to be in Cloud mode, and I’d recommend setting the connection timeout to 10s rather than the standard 5s, but it can still be called as normal from the PARFILE:

So the Data Masker element is reasonably straight forward – that’s the good news. But the thing you REALLY need to stop and think about is:

Where are our Dev and Test copies going to BE?

Option #1: If they’re going to be on VMs or local dev and test servers / developer machines then you could follow a similar approach to one I laid out in this blog post for Redgate in which you create a BACPAC file and split it out on premise before importing it and then provisioning from there. And you could use this code in my Github to achieve something very similar. Caveat: I am no PowerShell guru, who do you think I am? Rob Sewell? Chrissy LeMaire? No. Sadly not. So you can build your own logic around my code though, have at it, I don’t mind! ^_^

Option #2: Keeping everything in Azure. You can copy databases around in Azure and it seems to work pretty well! So I wrote this PowerShell (also in my GitHub for y’all) to effectively copy a PROD DB into the same resource group, mask it and then copy it across to a Dev/Test resource group, dropping the temp copy so as not to incur lots of extra Azure costs (this is just one of the methods I’ve seen people use, again it’s up to you!) – again, see the caveat in option #1 above for my statement on PowerShell! The good thing is, you can use the ‘&’ simply from PowerShell to call Data Masker’s command line.

Either of these options can be run from Azure DevOps also as part of your provisioning or working processes, but instead of including a call to the command line, you can run a fun PowerShell script instead:

Second Conclusion *sigh*

There are lots of ways to get what you need into Dev and Test, but these copies should be masked if they contain personal, identifying information. There are some methods above but there are plenty of others out there on the internet and if you’re not sure about getting started with data masking; try my post here – happy masking!