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Exploring the vCloud API Using Ruby

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While working on something that was completely random, I started to play around a bit with the Ruby programming language. I had a few questions and I reached out to a buddy of mine who is Ruby developer and in doing so I was introduced to a very cool Ruby gem called HTTParty. For those of you who are not familiar with Ruby gems, it is a packaged library or application for Ruby, similar to an rpm or pkg file. The neat thing about HTTParty is that it makes working with REST APIs extremely easy and processing XML request/responses into Ruby objects without too much effort.

With the bit of knowledge I gained from my buddy, I wanted to see how easy it would be to apply this to the vCloud API using Ruby and HTTParty. To my surprise, it was actually pretty easy!

Disclaimer: I am not a developer nor even a Ruby novice. This is probably the second or third time I have used Ruby.

Before getting started, you will need to have the following installed on your system:

The following vCloud APIs are implemented in the sample below:

To demonstrate the use of Ruby & HTTParty, I created a very simple Ruby script called vcd.rb which primarily deals with vApp operations.

To use the script, you will need to create a file called config-vcd.yml which contains the credentials to your vCloud Director instance. Here is what the file should look like:

:username: administrator@system
:password: supersecretpassword
:site: https://vcd.primp-industries.com

Note: This example assumes you are running vCloud Director 5.1 (but sample can be modified to support 1.5)

Here is an example of listing all vApps for the given Organization you are logging into:

Here is an example of listing a specific vApp:

Here is an example of performing several operations on the vApp:

At the end of this little exercise, I was pretty impressed at how easy it was to work with REST APIs using Ruby and HTTParty. I think the toughest part for me personally was getting used to Ruby's syntax which I was not familiar with. I also extended this exercise to the vCloud Networking and Security REST APIs which I will share in another blog post.

Useful Resources:

 

How To Backup & Restore Free ESXi Host Configuration

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ESXi host configurations can easily be backed up and restored using either the vCLI's vicfg-cfgbackup or PowerCLI's Get-VMHostFirmware cmdlet. These commands along with others that perform "write" operations are only supported when you have a (paid) licensed version of ESXi. If you are using free ESXi, the remote commands are only available for "read-only" operations. For more details, please refer to this article here.

Note: In my personal opinion, it is much quicker and more efficient to re-install ESXi and apply your configurations using either a scripted deployment such as kickstart or a combination along with post configuration scripts. Re-installs become extremely trivial when you centralize your ESXi host configurations, even for small setups.

Having said that, if you are running free ESXi in a small shop or in a home lab and wish to backup your ESXi host configurations, you can still do so by leveraging a neat little tool called vim-cmd found within the ESXi Shell. There is a section under hostsvc/firmware which manages the ESXi host configuration which also uses the same vSphere APIs that both vicfg-cfgbackup & Get-VMHostFirmeware command uses.

Under this section of vim-cmd, there are four commands:

  • backup_config   
  • reset_config    
  • restore_config  
  • sync_config

Prior to actually backing up your ESXi host configuration, run the following command which will flush the ESXi configuration changes:

vim-cmd hostsvc/firmware/sync_config

To backup the ESXi host configurations, run the following command which will generate a file that will be automatically stored in /scratch/downloads and can also be downloaded from a web browser using the URL shown from the output:

vim-cmd hostsvc/firmware/backup_config

Before restoring your ESXi host configurations, you will need to ensure the file is renamed to configBundle.tgz and stored under /tmp directory. You will also need to ensure the ESXi host is placed in maintenance mode by running the following command:

vim-cmd hostsvc/maintenance_mode_enter

To restore the ESXi host configurations, run the following command and specify the backup configuration file which should reside in /tmp/configBundle.tgz:

vim-cmd hostsvc/firmware/restore_config /tmp/configBundle.tgz

Note: Upon completing the restore, it will automatically reboot your ESXi host.

Here is a screenshot using the above commands to backup and then restore ESXi host:

Note: You can not restore an ESXi host using a configuration file backed up from a different host.

Enable Auto Startup After Power Failure For Apple Mac Mini

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I recently came across a very useful tidbit after receiving several inquires asking how to configure an Apple Mac Mini to automatically startup after a power failure. This is extremely useful for situations where power is eventually restored and you are not physically around to press the power button. Automatically starting up after a power failure is not a new feature of the Mac Mini and it actually exists on most modern day systems and can be configured using a variety of tools.

The challenge arises when you are running ESXi, how do you go about enabling this functionality in ESXi itself? Well the answer is actually quite simple, you can enable this outside of ESXi. Normally to enable this feature you can either run a setpci command on UNIX/Linux system or configure the energy saver settings in OS X. Several folks from the VMTN community such as zippytiff and twuhabro have already confirmed having success using the latter option when booting OS X off a USB or SD card to modify the energy saving settings.

I finally got a chance to look into this a bit more for myself and with a bit of research, I found several other methods which also works and may potentially be easier.

Note: I have heard that historically the auto startup flag has not persisted in older Apple hardware, but for the new Mac Mini 5,3 and 6,2, they seem to be persisting without any issue from my testing. YMMV depending on your hardware and/or firmware.

Method 1 (Configure in OS X)

If you already have OS X install on your Mac Mini, then you just need open up the System Preferences and enable auto startup under the Energy Saver section. Once that has been enabled, you can then perform your ESXi installation.

If you already have ESXi installed, then you can use either Method 2 or 3.

Method 2 (Configure using bootable Ubuntu on USB)

We can create a bootable Ubuntu image running off of a USB device (minimal footprint) and run the following setpci command to enable auto startup:

setpci -s 0:1f.0 0xa4.b=0

If you are interested in the gory details on the above command, please refer to this great article which breaks it all down for you. After you have created your Ubuntu image using the instructions in the above link, you can boot off of the USB device (Make sure to hold down ALT/OPT key so you can select to boot off of the USB device). Once Ubuntu has booted up, you will right click on the purple icon on the upper left hand corner and type in terminal.

You will then launch the terminal application and type the following to change over to root user.

sudo su -

Finally, you will enter the above setpci command which will enable the auto startup. At this point, you can type reboot and remove the USB device.

Method 3 (Configure using bootable OS X on USB)

Another method is to create a bootable OS X image running off of a USB device and change the power management settings by using the pmset utility. To enable auto startup, run the following command in the terminal:

pmset autorestart 1

You will need the original OS X installer and if you are using either Lion or Mountain Lion, you can use Lion DiskMaker to help you create the bootable USB image (Make sure to hold down ALT/OPT key so you can select to boot off of the USB device). Once the OS X installer boots up, at the top select Utilities and click on the Terminal application.

Go ahead and run the above command to enable auto start and then type reboot and remove the USB device.

The last thing to do of course is to actually test this out on your Mac Mini. Go ahead and let the system boot up and then yank the power cord and then give it a few seconds before plugging it back in. You should see the Mac Mini automatically power back on after you plug the power back in.

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