Problem: I was working on getting a demo on how to setup Always On with SQL Server 2017 without the need of creating a windows cluster, I had my two VM's in Azure and everything was working fine until the creation of the availability group, it failed and it was because the account under which the server was running was the default "NT Service" which is not allowed (not to mention is a concerning security issue) so instead I decided to join both VMs to a domain, as mentioned before, this were Azure VM's so the creation of a traditional domain as you know it on premises was a hard task to do (not to mention the cost for each of the servers) however by looking through I came across a service, Azure AD Domain Services that provides a seamless experience as a traditional domain controller, but as a service (PaaS) which is great because it does almost everything for you so here are the steps as to how to set that up.
All the steps are in this URL: https://docs.microsoft.com/en-us/azure/active-directory-domain-services/active-directory-ds-getting-started follow it thoroughly however, here are some annotations from my own experience:
Task 1: "configure basic settings"
DNS domain name: choose the name of your preference with the add of ".onmicrosoft.com" unless you have something else configured it won't check your name as valid.
Resource group: You can create a new resource group or use an existing one, it won't break anything that you have in your group if you choose "Use Existing"
Task 2: "Configure network Settings"
In here you have the option to either Create a new one or use an existing one, my recommendation, create a new one, in my first attempt I choose an existing one and spent 2 days cleaning everything up as in the middle of the creation it fail.
Task 3: "Configure administrative group"
In this task you create the equivalent of "Domain Administrators" group, so make sure that you add the members you want to be domain admins in your Azure AD (AAD).
After finishing this task, it will start the process on provisioning the resources, once this is done, your domain will be almost ready, before that you still need to configure your DNS. How to know when is done? When you go into the overview of the domain you are able to see the section "Update DNS Server settings for your virtual network"
Task 4: "Update DNS Server settings for your virtual network"
Make sure that you choose "custom" and copy both IPs onto the boxes as shown in the steps, this step is so that you can configure you DNS servers with the ip of the services (that will serve as Domain controller servers) Azure provided for you, take this as a verification step of the process.
With that you are done, you have successfully configured your Active directory as a service and you are good to go and work like if you were in an on premises domain, you will only need to configure your accounts to the services or if you didn't do it in the task #3, you can create an account to manage your domain (Join the machines, create other accounts to configure as Service Accounts, ETC).
In a following post I'll show you how to create and enable users in your Azure AD.
Thanks for reading!