vSphere Web Client

Detecting duplicate VM MAC Address using vCenter Server Alarm

02.25.2015 by William Lam // 6 Comments

Having a duplicate VM MAC Address in your environment can lead to an extremely painful day of troubleshooting and it can also be tough to prevent depending on how and where you provision your VMs.

There are two cases that I can think of where a duplicate MAC Address can potentially occur:

You manually assign a static MAC Address versus using dynamic assignment (includes VM import) and it conflicts with an already assigned MAC Address
You migrate a VM from one vCenter Server to another and the destination vCenter Server has already assigned the MAC Address of the migrated VM

In both of these scenarios, when a duplicate MAC Address occurs, time is of the essence to quickly pin-point the source of the duplicated entry and quickly resolving the conflict. What would be nice is to be able to automatically detect that a MAC Address conflict has occurred and provide the necessary information of the offending VMs.

UPDATE (4/22) - Thanks to Petr, it turns out there is another MAC Address conflict event which I did not know about specifically for detecting duplicate entries for manually assigned MAC Addresses called "VM static MAC conflict". I definitely recommend creating an alarm for both Events for the vCenter Alarm.

While performing some research in my lab environment the other day, I accidentally stumbled onto this little tidbit in vCenter Server. It turns out there is an out of the box event called "VM Mac conflict" which can be triggered using a vCenter Server alarm when a duplicated MAC Address is detected for a VM. I was actually surprised that this was not one of the pre-created default alarms in vCenter Server as I can see this being extremely useful to have out of the box. In any case, it is simple enough to create a new vCenter Server Alarm and in the example below I called it "Dupe VM Mac Address".

To test our new alarm, I created a new VM called "VM1" which has been configured with static MAC Address that matches "VM2". Once the VM has been created, we can see that the alarm is immediately triggered and by clicking into the alarm details, it provides the details of the MAC Address and the offending VMs.

In my opinion this is an alarm that everyone should create in their environment to ensure that if this problem ever occurs, you can quickly get notified and resolve the problem. I have also reported this internally and asked if we can have this alarm created by default, so hopefully this will not be necessary in the near future 🙂

Accessing the vSphere Web Client from a Linux desktop?

02.25.2015 by William Lam // 9 Comments

A common miss-conception about the vSphere Web Client is that it is not accessible from a Linux-based desktop. Contrary to popular belief, this is actually possible at least from a technical standpoint as alluded to in this VMware KB. A recent discussion about this topic had piqued my interest as my own understanding of whether the vSphere Web Client would even work on a Linux desktop is fuzzy at best since it is not a desktop OS I use on a regular basis.

Though this may still comes as a surprise to some folks, Adobe Flash is indeed a requirement to use the vSphere Web Client. There are actually two ways to satisfy this requirement using any modern Linux desktop distribution. In the example below, I am using the latest Ubuntu Desktop 14.04 distribution to demonstrate the two options.

The first option is the most "convenient" by simply using the latest version of Google Chrome browser which actually bundles the Pepper Flash Plugin (more details can be found here from Adobe). Here is the CLI commands to perform the installation of Google Chrome on Ubuntu, you acn easily do a search for the instructions for other Linux distributions.

sudo sh -c 'echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list'
wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -
sudo apt-get update
sudo apt-get -y install google-chrome-stable

Here is a screenshot using Google Chrome connecting to a vSphere 6.0 environment as well as accessing the VMRC of a VM:

The second option is slightly less "convenient" since you need to install the Pepper Flash Plugin in addition to the browser that supports this plugin which is Chromium. Here is the CLI commands to perform the installation of Chromium on Ubuntu, you can easily do a search online for instructions for other Linux distributions.

sudo apt-get update
sudo apt-get -y install pepperflashplugin-nonfree
sudo apt-get -y install chromium-browser

Here is a screenshot using Chromium connecting to a vSphere 6.0 environment and you will also be able to access the VMRC of a VM:

This looks pretty good right? I mean you can login to the vSphere Web Client UI to perform basic operations and access the VM Console using the HTML5 based VMRC. Well, almost but there are a couple of caveats to be aware of which may not be obvious at first. In addition to the basic operations and VMRC access, there some other important capabilities the vSphere Web Client offers today:

Deploying OVF/OVA
Windows Session Authentication
Uploading files to a vSphere Datastore
Mounting ISO/Floppy Image
Connecting Local Devices (e.g. USB/CD-ROM)

The above capabilities are made available through what is known as the Client Integration Plug-in (CIP) which is something that is downloaded from the vSphere Web Client Server and installed locally on your desktop. A Linux CIP installer is currently not available today and the above functionality would not be available in the vSphere Web Client. Having said that, not all is lost and there are some workarounds. If you wish to deploy an OVF/OVA, you can still install OVFTool which is available on Linux and instead of using the UI to drive the deployment, it can be done through the CLI. For uploading files like an ISOs, you can use the vSphere API/CLI as shown here or SCP'ing directly to the ESXi host. Once the ISO is uploaded, you can then mount it to your VM from the vSphere Datastore.

Though this is far from a perfect solution for Linux-based desktop users, it does allow you to access the basic management capabilities of the vSphere Web Client. There is definitely room for improvement and this is an area that PM/Engineering is looking to enhance further in the future. There has also been a ton of general performance and usability improvements in the new vSphere 6.0 Web Client which will benefit all platforms and if you are interested to learn more about those, check out the blog post from the vSphere Web Client PM here.

How to customize the new vSphere 6.0 Web Client login UI?

02.17.2015 by William Lam // 35 Comments

A common feature request that I hear from customers from time to time is the ability to customize the login screen for the vSphere Web Client. Going beyond just aesthetics such as adding an organizations logo or colors, it is often a mandatory requirement for some organizations to display a security or warning banner to the users prior to logging in. In prior releases of vSphere, the login page of the vSphere Web Client (which is actually from vCenter Single Sign-On service) was written in Flash which meant that it was impossible to change without recompiling the source code.

In vSphere 6.0 (yes, vSphere 6.0 is required), the vCenter Single Sign-On login page is now written using regular HTML and CSS. This means you can actually now customize the login page with your own logos, colors or text that you wish to display to your end users. Not only can you customize the login for vCenter Server but you can also do the same for vRealize Automation Center as long as you are using the latest version of the Platform Services Controller which now provides other services in addition to vCenter Single Sign-On.

UPDATE (07/14/16): For vSphere 6.0 Update 2 environments, please follow the instructions here as there have been some minor changes. This article is only applicable for vSphere 6.0 and vSphere 6.0 Update 1 environments.

Disclaimer: This is not officially supported by VMware, if you decide to enable this, please use at your own risk and ensure you backup all original files in case you need revert back to the original configurations.

There are two specific files that you will want to take a look at, the first is unpentry.jsp which controls the look and feel of the actual login page and the second is login.css which controls the stylesheet for the login page. If you wish to include your own images including gifs (which I did not expect would work), there is a img directory that you can reference. Below are the paths to these configuration files for both a Windows vCenter Server and the VCSA 6.0.

Windows vCenter Server 6.0 / 6.0u1

C:\ProgramData\VMware\vCenterServer\runtime\VMwareSTSService\webapps\websso\WEB-INF\views\unpentry.jsp
C:\ProgramData\VMware\vCenterServer\runtime\VMwareSTSService\webapps\websso\resources\css\login.css
C:\ProgramData\VMware\vCenterServer\runtime\VMwareSTSService\webapps\websso\resources\img

VCSA 6.0 / 6.0u1

/usr/lib/vmware-sso/vmware-sts/webapps/websso/WEB-INF/views/unpentry.jsp
/usr/lib/vmware-sso/vmware-sts/webapps/websso/resources/css/login.css
/usr/lib/vmware-sso/vmware-sts/webapps/websso/resources/img

Note: It is highly recommended that you backup all original files before making edits so you can easily revert to the original configuration. If you are only updating the image to figure out layout and placement, you may notice changes are not reflected when you refresh the vSphere Web Client. The reason for this is that the image is only refreshed when the configuration files (.jsp) is updated. You can easily do this by simply opening it up and then saving it without making changes. I found this was the quickest way to force a reload of an updated image that has been uploaded.

I figure it might be cool to create a couple of vSphere Web Client "themes" for some of my buddies like Rawlinson Rivera, Duncan Epping, Alan Renouf, Mike Foley and Cormac Hogan. I hope Rawlinson likes his theme as I know how big of a fan he is 😉 I have also created a Github repo customize-vsphere-web-client-6.0 where you can find all the themes below. Feel free to create your own and contribute them back to the community.

Rawlinson Rivera Theme -

Duncan Epping Theme -

Alan Renouf Theme -

Mike Foley Theme -

Cormac Hogan Theme -

Here is an additional bonus theme as I could not leave out my good buddy CaptainVSAN!

I am looking forwarding to see what others come up with in terms of their own vSphere Web Client themes and be sure to share them back by either posting back here or better yet, contributing to the Github repository.

Image Sources:

http://www.twitterevolutions.com/bgs/justin-bieber-2.jpg
http://s1174.photobucket.com/user/D-A-C-20/media/Holland%20EUIV/Holland.png.html
http://www.chrisschofield.me/wp-content/uploads/2011/08/PowerCLIman.jpg
http://stream1.gifsoup.com/view6/2662404/you-didnt-say-the-magic-word-o.gif