My teammate Meagan (b|t) messaged me in Teams yesterday afternoon to say “Joey, the client created a new database using your automated process, and my ETL user (which is a AAD user) didn’t get created, can you fix it?” Well, after a quick perusal of emails I remembered that I had the asked the client to add the create user process to their initial population process which hadn’t occurred yet. The reason why I did this was that creating an Azure Active Directory user in an Azure SQL Database from Azure Automation was painful and maybe not even possible. However, I pinged Rob Sewell (b|t) about the best way to do that. This sounded not that bad to do, but I managed to hit land mines around every corner.
The First Problem
Azure Automation is mostly PowerShell only—there is a Python option, but I’ve never used it, and I’m not going to start now. The trick with PowerShell is that it’s great for things you have to do to Azure Resources, it’s far less good for things you have to do inside of databases (think creating a user). I typically use the invoke-sqlcmd cmdlet, however we have a chicken and egg problem—I can’t create an AAD user from a SQL connection (a connection made using a SQL login) and invoke-sqlcmd doesn’t support authenticating with AAD. The Azure Automation service allows you to import 3rd party soluitons from the PowerShell gallery, so you can use DBATools which I did here. Rob has an excellent blog post here that describes this process.
$appid = (Get-AzKeyVaultSecret -vaultName “beard-key-vault” -name “service-principal-guid”).SecretValueText
$Clientsecret = (Get-AzKeyVaultSecret -vaultName “beard-key-vault” -name “service-principal-secret”).SecretValue
$credential = New-Object System.Management.Automation.PSCredential ($appid,$Clientsecret)
$tenantid = (Get-AzKeyVaultSecret -vaultName “beard-key-vault” -name “Sewells-Tenant-Id”).SecretValueText
$AzureSQL = Connect-DbaInstance -SqlInstance $SqlInstance -Database $databasename -SqlCredential $credential -Tenant $tenantid -TrustServerCertificate
Invoke-DbaQuery -SqlInstance $AzureSql -Database $DatabaseName -SqlCredential $credential -Query $query
The code, which I happily stole from Rob’s blog allows me to connect as a service principal. To easily facilitate this I made my automation account part of my DBA group (the Azure AD Admin group for the Azure SQL Server), which you can assign without this ridiculous process. I threatened to add Meagan’s ETL user to that group, but she was going to out me on Twitter.
After running that code I could connect to Automation run as account to my Azure SQL DB, but my query was failing with the following error:
I’m logged as a service principal there—hence the weird GUID, you can see that I have basically every privilege in SQL Server, but I can’t create a user from an external provider. PowerShell (and automation) say that the user could not be resolved.
The Next Land Mine
So I DMed Rob, and asked him WTF? It turns out for this to work, you need to create a service principal for your Azure SQL Database. If you aren’t familiar with service principals they are analogous to service accounts in an on-premises world. Doing this was the easiest step in the process—I have a PoSH script to hit every server in my subscription, and it was trivial to add a service principal as well as add to my database runbook. However, that was just the first part.
You have to give the service principal the “directory reader” permission in Azure AD, and the effective way to do this with Automation is to assign that privilege to a group. Well, it turns out adding AAD roles to group is a relatively new feature (it’s in preview) and more importantly requires P1 or P2 Azure Active Directory which has a per user cost. Which meant I needed to get approval. After much chatter on a DCAC teams channel I discovered since this feature was not user-assigned (e.g. it’s enabled for the entire AAD tenant once it’s enabled) I only had to have one AAD license in the tenant (I assigned it to Meagan). Once that was in place, I could grant the directory permission to the SQL Server Service Principals group.
Are We Done Yet?
I should have noticed in the documentation provided by the SQL team assigning groups with PowerShell, that there was a reference to the preview PowerShell module for Azure AD (I did, but I didn’t think it mattered because I was just assigning a user to a group). So I thought I had everything wired up when I started getting the following error:
Add-AzureADGroupMember -ObjectId $g.objectid -RefObjectId $miIdentity.ObjectId
Add-AzureADGroupMember: Error occurred while executing AddGroupMember
Message: Insufficient privileges to complete the operation.
DateTimeStamp: Tue, 25 Aug 2020 13:14:08 GMT
I have Global Admin and Subscription owner in the two environments I was testing in, so clearly this wasn’t a permissions issue. To further prove that point, I was able to add the service accounts I had created to the group through the Azure portal. So after writing like three emails with my further discoveries to the Azure MVP distribution list (I could add the service principal to a regular group, just not one with a role assigned to it). I went back and decided to play with that preview module.
Everything up to this point is me being an idiot, but I’m going to yell at Microsoft for a second. I couldn’t install the azureadpreview on my Mac because its dependent on Winforms—I thought Az modules were all supposed to be built on .NET core. I also couldn’t get it to run in cloud shell, which may be related to the Winforms thing, or not.
I do have a Windows VM, so I installed the module there, and it successfully worked on the DCAC tenant. I went to Azure Automation to install the module. If you’ve never imported a module into Azure Automation, you should know that the portal notification about a module import being complete is meaningless, because Azure Automation is a lying liar who lies.
Look on the modules page and hit refresh a lot. It usually takes 1-2 minutes for a module to import. I messaged Kerry in Teams.
And what do you know? It worked. I was concerned and about ready to murder someone, but it worked. Rob’s code is really helpful and he covers key vault in his post. I did have some open GUIDs in some of my code pictures, it’s cool those aren’t sensitive. However, you should store all your secrets in Key Vault as it’s fast and easy.
The other thing I learned in this process is that you can now make a guest user you Azure Active Directory Admin (this means I could make email@example.com or firstname.lastname@example.org an admin in the joeydantoni.com tenant), which you weren’t able to do before. Prior to this you could use a group and add a guest user to that group as I mentioned above. (Note: you should still use a group and not a single user as it’s best practice)