Azure - assign managed identity access to VM before setup

Question

I am writing a program in Java that creates a VM instance in Azure, uploads a script to a container, and downloads and executes the script in the VM. However, I am currently facing a difficulty in granting the machine access to the container. When the machine is already up, I can manually go to Azure and assign a role with access, however I want to do that in my program (when creating the VM) before the machine is up, so that the program can run uninterrupted. Is there a way to do that? From the Documentation

Currently, the Azure portal does not support assigning a user-assigned managed identity during the creation of a VM. Instead, refer to one of the following VM creation Quickstart articles to first create a VM, and then proceed to the next section for details on assigning a user-assigned managed identity to the VM

Am I understanding correctly that it is not possible? Is there a workaround?

Answer 1

It is possible, the doc just means you can't do that in the portal, not mean in the code.

In your case, actually I am not sure you want to use system-assigned identity or user-assigned identity.

Here is a sample which creates a Linux VM with system-assigned identity enabled via withSystemAssignedManagedServiceIdentity , if you want to use user-assigned identity, you could change the code to use WithUserAssignedManagedServiceIdentity , you can specific an existing or not-yet-created user assigned identity, it depends on your requirement.

VirtualMachine virtualMachine = azureResourceManager.virtualMachines()
                    .define(linuxVMName)
                        .withRegion(region)
                        .withNewResourceGroup(rgName)
                        .withNewPrimaryNetwork("10.0.0.0/28")
                        .withPrimaryPrivateIPAddressDynamic()
                        .withNewPrimaryPublicIPAddress(pipName)
                        .withPopularLinuxImage(KnownLinuxVirtualMachineImage.UBUNTU_SERVER_16_04_LTS)
                        .withRootUsername(userName)
                        .withRootPassword(password)
                        .withSize(VirtualMachineSizeTypes.STANDARD_DS2_V2)
                        .withOSDiskCaching(CachingTypes.READ_WRITE)
                        .withSystemAssignedManagedServiceIdentity()
                        .create();