Configure Active Directory authentication with SQL Server on Linux

Microsoft just released the adutil in public preview which is a CLI based utility developed to ease the AD authentication configuration for both SQL Server on Linux and SQL Server Linux containers.

We don’t need to switch to a Windows machine to create the AD user for SQL Server and setting SPNs.

In the following steps I will try to install a SQL Server instance on Linux using just the Linux CLI tool adutil.

We will need 2 VMs:
  • tf-wincore01.lab.local – Domain Controller (DC) running on Windows Server 2019 Core (will
    host the lab.local domain)
  • tf-ubuntu01.lab.local – Ubuntu 18.04 LTS – SQL Server Instance on port 20001 will be
    installed here

I will be creating a brand new environment for this test and I am using Terraform to provision the VMs .

 

 

 

 

 

 

 

 

Prepare the Domain Controller

Once the VMs are created we need to configure the domain controller:

Let’s setup our zones:

 

Note that this AD configuration is just the bare minimum for our lab and it’s not fit for a Production
environment!

Join the Linux host to the domain

It’s now time to join the Linux box to our new domain.

The yaml file used by netplan needs to point to the domain:

Confirm the configuration and apply it.

In my case, the file looks like this:

 

 

 

 

 

 

/etc/resolv.conf file should also point to the domain:

 

 

Next, we install the packages that will allow us to join the machine to the domain:

Let’s also set the hostname:

We are now ready to join the machine to the domain:

This command:

  • creates a new computer account in AD
  • creates the /etc/krb5.keytab host keytab file
  • configures the domain in /etc/sssd/sssd.conf
  • updates /etc/krb5.conf

Let’s verify that we can now gather information about a user from the domain, and that we can acquire a
Kerberos ticket as that user.

The following example uses id, kinit, and klist commands for this.

Install adutil

We now need to install the adutil so we can interact with the Domain Controller directly from the Linux box.

 

Create a domain user using adutil

Let’s try to create a regular AD user:

At this point adutil cannot list the users, but we can check if an account exists in the AD

 

 

Install SQL Server instance on the Linux host

From this point on, I can proceed at installing the SQL Server instance on the Linux host:

 

Create an AD user for SQL Server and set the ServicePrincipalName (SPN) using adutil

SQL Server instance is running and let’s now create an AD user for SQL Server and set the ServicePrincipalName (SPN) using the adutil tool.

 

Test the connections and the authentication scheme

Let’s create an AD-based SQL Server login:

Connecting as a domain user from the Linux box:

Let’s verify the authentication scheme:

 

 

Conclusion

Our setup is now complete and we managed to perform all the required operations from a Linux machine.

The same can be applied to provision SQL Server running on Linux containers.

This also should apply if you’re running in the cloud.

Leave a Comment


NOTE - You can use these HTML tags and attributes:
<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code class="" title="" data-url=""> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong> <pre class="" title="" data-url=""> <span class="" title="" data-url="">

This site uses Akismet to reduce spam. Learn how your comment data is processed.

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close