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VM provisioning from e-mail using Python and the VMware Perl SDK

August 21st, 2013 2 comments

This is a bit of a fun project that I did as a part of my presentation of the vPi project. It doesn’t necessarily achieve anything useful (at least not on the surface), but it does demonstrate some techniques that could be put to far greater use.

 

vpi-provision-script

 

In summary, this integration turns e-mails from people into Virtual Machines on a vSphere environment. It consists of the following components:

  • Raspberry Pi running the vPi image
  • Python script
  • VMware Perl script (vmcreate.pl) + a bit of XML used for the VM template.
  • VMware Perl script (vmcontrol.pl)

The way it works, is a Gmail mailbox is setup to capture e-mails sent to a specific e-mail address. The Raspberry Pi runs a Python script that logs into Gmail, and looks for any new e-mail that has arrived. If an e-mail is found, it takes the FROM address and splits it up into components, determining the sender’s first and last names.

The script then opens up the XML template file that the vmcreate.pl script uses as a basis to creating VMs, and searches it for a bit of bespoke text we placed there called “TEMPLATE_NAME”. Once found, it strips this out and replaces the TEMPLATE_NAME with the sender’s name.

We then move onto the next procedure, which involves invoking the vmcreate.pl script from the Python script, passing it in the parameters required (such as the server to connect to, credentials, and the all important XML template). This runs against the vSphere environment in question, and creates a VM named after the e-mail sender, (appending a random string of text and numbers to the end to ensure that multiple e-mails from the same person do not cause an issue with duplicate named VMs).

Once the VM is provisioned, the Python script invokes the vmcontrol.pl script using the name of the VM we just provisioned to power the VM up. Lastly, the Python script sends an e-mail back to the sender, stating that their VM has been created and powered on. After that, voila! You will have a new VM created and deployed in your Datacenter all triggered from a simple e-mail.

vpi-example

The script files required + XML and XML schema files are available for download below. The main python script is fairly lengthy, so I won’t include the content direct on this post. Just download the file to grab everything.

Notes to get the script up and running:

  • I found the vmcreate.xsd (XML Schema file) for the VMware vmcreate.pl script did not work, so I had to modify it to change some of the property names to match those of which the vmcreate script was expecting. My updated version is included in the download below if you get any errors from the vmcreate.pl script. It’s default location is: /usr/lib/vmware-viperl/apps/schema
  • You will need to find and edit some variables in the main Python script – your mailbox name and password, plus the IP, username and password for the vmcreate.pl and vmcontrol.pl perl script calls.
  • In the vmtemplate.xml file you should define the characteristics of your VMs that are created. GuestOS, Disk size, etc… Of particular importance, is the name of your host to deploy to, Datacenter name, Datastore name to deploy to, and default VM network to use. These are all of course unique to your own environments.

 

vPi Presentation (1480)
 
Download VM from email provisioning script (472)

 

Once you start to think of other ways of using this, you can begin to imagine some really great (and even crazy) solutions. As a start, it would be quite easy to begin extending this, so that e-mails undergo some sort of validation first. E.g. does the domain the sender sent from exist in our “Whitelist” of people allowed to provision e-mails, or does a specific “password” required exist in the body of the e-mail etc…

How about having a standard e-mail template, where the sender can specify more details, such as vCPUs, RAM, disk sizes, OS to install? You could then provision from VM templates instead of creating new VMs, that have customization specs attached. Once powered up and provisioned, a script within the VM could be initiated to accept parameters the VM was created with, and use those to send the requestor an e-mail to say “Hey! I’m now ready for you to connect, and here is the IP you can use…”.

 

Of course, this is not limited to vPi and the Raspberry Pi – that was just the platform I demonstrated this on. Being standard SDKs and scripting languages, you could use the above solution anywhere.