AzureVM: managing virtual machines in Azure

Creating a VM

Creating a VM is as simple as using the create_vm method, which is available as part of the az_subscription and az_resource_group classes.

library(AzureRMR)
library(AzureVM)

## using the subscription method
sub <- az_rm$
    new(tenant="{tenant_id}", app="{app_id}", password="{password}")$
    get_subscription("{subscription_id}")

myNewVM <- sub$create_vm("myNewVM",
    location="australiaeast",
    username="datascience",
    passkey="fAs30q-2a5vF!Z")  # be sure to choose a strong password!


## using the resource group method
rg <- sub$create_resource_group("myresourcegroup",
    location="australiaeast")

myOtherVM <- rg$create_vm("myOtherVM",
    username="datascience",
    passkey="l3Kgrf21%?0DFm")

Without any other options, this will create a Windows Server 2016 Data Science Virtual Machine, which is pre-installed with several tools useful for analytics: Python, R (and RStudio), Tensorflow, XGBoost, SQL Server, and so on. The size will be a Standard DS3 V2 VM, which has 4 cores, 14GB of memory, 1TB primary disk, and up to 16x28GB data disks.

myLinuxVM <- sub$create_vm("myLinuxVM",
    location="australiaeast",
    size="Standard_NC6s_v3",
    os="Ubuntu",
    username="datascience",
    passkey=readLines("~/id_rsa.pub"),
    userauth_type="key")

# examine VM sizes available in australiaeast region
sub$list_vm_sizes("australiaeast")

Retrieving an existing VM

If you have an existing VM, you can retrieve it with the get_vm() method. As with create_vm(), this is available as part of the az_subscription and az_resource_group classes. The only argument you need to supply is the name of the VM.

## using the subscription method
sub <- az_rm$
    new(tenant="{tenant_id}", app="{app_id}", password="{password}")$
    get_subscription("{subscription_id}")

# retrieve the VM we created above
myNewVM <- sub$get_vm("myNewVM")


## and with the resource group method
rg <- sub$get_resource_group("myresourcegroup")

myOtherVM <- rg$get_vm("myOtherVM")

Working with a VM

There are various things you can do with a VM object within R.

To stop (shutdown) a VM, call its stop() method. The deallocate argument sets whether to deallocate its resources as well, with the default being TRUE; you may want to set this to FALSE if you know you will be restarting the VM soon. To restart it, call either the start() or restart() method. The main difference between the two is that restart() will shutdown the VM first if it is currently running.

To sync the object with the resource in Azure, call the sync_vm_status() method. The most common situation where you might want to do this is if you create a VM with the argument wait=FALSE. In this case, rather than waiting for provisioning to complete, the create_vm method will return an incomplete VM object; you then call its sync_vm_status() method to update it with how the provisioning is going in Azure.

To dynamically resize a VM, call the resize() method with the new size. This has an optional deallocate argument controlling whether to stop and deallocate the VM first (which is sometimes necessary for successful resizing).

To run a script in the VM (without manually logging in), call the run_script() method. This will be a PowerShell script if it is a Windows VM, or a bash script if it is Linux. The script is just a character vector.

# simple bash script for executing on a Linux VM
script <-
'#!/bin/bash

var=Hello world!

# redirect output to a file so we know whether it ran successfully
echo "$var" > /tmp/helloworld.txt
'

vm$run_script(script)

If you login to the VM after running this script, you should find the file helloworld.txt in the /tmp directory.

Deleting a VM

Simply deleting a virtual machine object in R, eg with rm(), will not do anything to the VM itself in Azure. To delete the VM and its resources, call the object’s delete() method:

vm$delete()

AzureVM will prompt you for confirmation that you really want to delete the VM. By default, this will also free up all the individual Azure resources used by the VM, such as its storage, network interface, security group, and so on.

If you created the VM using the create_vm() method of the az_subscription class, the deletion process is very simple: it simply removes the resource group containing the VM. This is possible because the resource group was created as part of deploying the VM. Be aware that any other resources you may have created in this resource group will also be deleted.

Alternatively, you can use the delete_vm() method of the az_subscription and az_resource_group classes. These will retrieve the VM of the given name and then call its delete() method.

GPU enabled VMs

myGpuVM <- sub$create_vm(size="Standard_NC12s_v3", ...)

sub <- az_rm$
    new(tenant="{tenant_id}", app="{app_id}", password="{password}")$
    get_subscription("{subscription_id}")

# create a cluster of 5 Ubuntu VMs
vmCluster <- sub$create_vm_cluster("vmCluster",
    location="australiaeast",
    os="Ubuntu",
    username="datascience",
    passkey=readLines("~/id_rsa.pub"),
    userauth_type="key",
    clust_size=5)