Add new user to all my Azure subscriptions

I found myself needing to add the same user as an owner to all my Azure subscriptions. If I could ever retain Powershell syntax, I could write a clever script that would loop through all the subscriptions and do what was needed. Alas, that forever eludes me so I just opted for a few Azure CLI commands with a bit of editing in an editor. Still much faster than going throgh the UI repeatedly.

Multiple tenants

For most people, this doesn’t apply so feel free to skip this section if it is irrelevant.
When you log in with Azure CLI, you can see all your subscriptions across tenants - but the command to add a user to a subscription only works for the tenant you are currently “logged in to”. It can be confusing.
To see the tenant IDs for all your subscriptions you can run this:

 az account list --query "[].{tenantId:tenantId, name:name} | sort_by([],&tenantId)"  --output table

In order to “login” to a specific tenant you need to :

az login --tenant <tenant id>

Then do the stuff below for each tenant id

Getting the list of subscription IDs

First, get the list of subscription ids for a given tenant id:

az account list --query "[] | [?tenantId == ''].id" --output table

Note that the tenant id may be in this form or may be a guid - not sure why.
Alternatively, if you only have a single tenant, just do:

az account list --query "[].id" --output table

Add the user to all the subscriptions

Copy the list of subscription IDs into a text editor and modify each line to look like this (111… being the subscription id):

az role assignment create --role "Owner" --assignee --scope /subscriptions/11111111-1111-1111-1111-111111111111

Copy those lines into your console and shortly after your new user will be an owner of all your subscriptions.