Managing VM guests using vmrun.
The easiest way to get started with VIX is by using the vmrun command which is packaged inside of VIX. It's a command-line executable that doesn't require a development environment, and is pretty easy to use once you get the hang of it.
Since I mostly use ESX, I want to take an ESX-centric view of using vmrun in this post, and I'm also going to focus on what you can do to the guest operating system within VMs. Specifically I'm going to address two use cases that I think are pretty important and useful:
- Installing an agent within a VM.
- Restarting a service on a Windows VM.
First, you'll need to install VIX 1.6.2. On Windows you'll find vmrun in %PROGRAMFILES%\VMware\VMware VIX. On Linux it should be available in your path, so you can just run it from anywhere. Next, make sure you've got an ESX 3.5 update 2 or higher server to run commands against. In addition, you'll need a VM whose operating system is running an up-to-date copy of VMware tools.
If you type vmrun with no arguments you'll get a listing of all the things vmrun can do, but I want to focus on guest operations, which are listed below.
Table 1: Guest operations supported by vmrun.
| Operation | Description | Supported on ESX? |
| runProgramInGuest | Run a program in Guest OS | Yes |
| fileExistsInGuest | Check if a file exists in Guest OS | Yes |
| setSharedFolderState | Modify a Host-Guest shared folder | No |
| addSharedFolder | Add a Host-Guest shared folder | No |
| removeSharedFolder | Remove a Host-Guest shared folder | No |
| listProcessesInGuest | List running processes in Guest OS | Yes |
| killProcessInGuest | Kill a process in Guest OS | Yes |
| runScriptInGuest | Run a script in Guest OS | Yes |
| deleteFileInGuest | Delete a file in Guest OS | Yes |
| createDirectoryInGuest | Create a directory in Guest OS | Yes |
| deleteDirectoryInGuest | Delete a directory in Guest OS | Yes |
| listDirectoryInGuest | List a directory in Guest OS | Yes |
| copyFileFromHostToGuest | Copy a file from host OS to guest OS | Yes |
| copyFileFromGuestToHost | Copy a file from guest OS to host OS | Yes |
| renameFileInGuest | Rename a file in Guest OS | Yes |
| captureScreen | Capture the screen of the VM to a local file | No |
| writeVariable | Write a variable in the VM state | No |
| readVariable | Read a variable in the VM state | No |
Use case: Installing an agent in your VM.
Installing agents is an integral part of managing large numbers of systems, whether physical or virtual. Usually you want to bake your agents into your OS image, but occasionally a new agent will come along that needs to be deployed to existing systems. This example shows how you can copy an agent from your desktop to your VM and install it. The only thing you need is an agent that can be installed without user intervention (which is the norm for agents anyway).
Please note: Commands should be entered all on one line, it's split up here just for the sake if fitting it into the blog.
Example 1: Copying an MSI file from your desktop to your VM.
vmrun -T esx -h https://esx.example.com/sdk -u root -p secretpw -gu user -gp userpw copyFileFromHostToGuest "[storage1] Windows/Windows.vmx" "c:\program files\my agent software\agent.msi" c:\agent.msi
One thing to point out here is that, despite the command saying "From Host to Guest" the file is actually being copied from the same system where vmrun is invoked (for example your laptop or workstation).
Next we use runProgramInGuest to install the MSI.
Example 2: Invoke the MSI file we copied above.
vmrun -T esx -h https://esx.example.com/sdk -u root -p secretpw -gu user -gp userpw runProgramInGuest "[storage1] Windows/Windows.vmx" c:\agent.msi
Use case: Restarting a service on Windows.
This one's really easy so I'll just show it without explanation.
Example 3: Restart a service on Windows.
vmrun -T esx -h https://esx.example.com/sdk -u root -p secretpw -gu user -gp userpw runProgramInGuest "[storage1] Windows/Windows.vmx" c:\windows\system32\net.exe restart dhcp
If Linux is more your style, tweak the last part to say something like /etc/init.d/sshd restart and you'll be restarting Linux services just as easily.
How do I get the path to my VMX file?
The hardest part about dealing with vmrun when you're managing ESX is knowing where your VMX file is. To get this you have to either log in to your ESX system and locate the VMX file, or you can use the VI API. Within the VI API, the VirtualMachine object contains a data structure called VirtualMachineFileInfo. The vmPathName property of this structure tells you the path to your VMX file. Not very pretty, but over time you'll see us rolling out some more convenient ways to access the functionality VIX provides. In the meantime there's a lot of really useful stuff you can do with tools like vmrun.
I've really had some fun after finding out about VIX, even for little hacky tasks: http://www.kelvinism.com/howtos/beginning-scripting-esxi/
Thanks for releasing another useful tool!
Posted by: Kelvin Nicholson | January 25, 2009 at 03:07 PM
Does copyFileFromHostToGuest() this Vix API copy security information also? (ACL, EA)
Posted by: Tejas | May 14, 2009 at 08:00 AM
@Tejas
Not in the current releases. We are working on ACL, so stay tuned.
Posted by: Carter Shanklin | May 17, 2009 at 07:07 PM