vib

Creating a custom VIB for ESXi 8.x

07.25.2023 by William Lam // 2 Comments

Back in 2012, a VMware Fling was released called VIB Author, which allowed users to create their own custom vSphere Infrastructure Bundles (VIB) that typically would include configuration changes that was not possible when using the vSphere API such as enabling custom ESXi firewall ports or even bundling up custom utilities that could run within the ESXi Shell.

The VIB Author tool was eventually deprecated and removed due to the lack of support from Engineering, after all, it was released as a Fling. While the need for opening non-standard ESXi firewall port has greatly improved over the years, with the majority of 2nd and 3rd party solutions simply incorporating that into their solution offering, there are still use cases for requiring a custom VIB.

Even with the VIB Author Fling being deprecated, many in the community was still able to construct custom VIBs which were still compatible with later ESXi 5.x to 7.x releases. In fact, I even use the VIB Author to make it easier to distribute and install the popular ghettoVCB solution which can be installed using either a VIB or an Offline Bundle, another format the VIB Author tool supports creating.

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Neat way of installing or updating any VIB using just the ESXi Embedded Host Client

11.10.2015 by William Lam // 5 Comments

A couple of months back I had tossed out an idea on Twitter asking if others would like to see an automatic update mechanism built into the ESXi Embedded Host Client which would allow users to easily update to newer releases of the Fling versus the current method which requires copying the VIB and then running command in the ESXi Shell.

Wonder if its just me,but would others like to see an automatic update mechanism in the ESXi Embedded Host Client UI? pic.twitter.com/R9KFMOE4zu

— William Lam (@lamw) August 26, 2015

To no surprise, the feedback was an astounding yes! Literally within a couple of hours, Etienne Le Sueur, one of the two VMware Engineers working on the Fling shared a screenshot that demonstrated that this would possible. The first release of this feature would simply ask for the URL to the updated ESXi Embedded Host Client VIB and this was included in the v3 release of the Fling.

One additional tidbit that Etienne had shared was that the way this feature was implemented, it was not only limited to Embedded Host Client VIB but you could do this for any ESXi VIB. This is done by using the vSphere API and calling into the InstallHostPatchV2_Task() method which allows you to install or update an ESXi VIB from a URL source. Most recently, there a twitter conversation between myself, Etienne and Christian Mohn on how this capability could be further extended to include updating ESXi itself which can either be from an Image Profile or offline bundle. For those with a detailed eye, you may have noticed that the same API method can also support an offline bundle URL which would make this possible. As of right now, the feature is actually included in an internal build of the Embedded Host Client, but perhaps we will see this in a future update of the Embedded Host Client? 😉

Going back to the original topic of this blog post, to use the VIB install/update mechanism, you would need to first upload the ESXi VIB to an HTTP Server and then specify the URL. This is fine if you have an existing HTTP Server but if you do not, it is sort of a pain and though there are other methods like uploading directly to the ESXi's python based HTTP Server as mentioned by Christian, it would still require using something like SCP which is an additional step. My initial goal and hope was to be able to install or update an ESXi VIB or ESXi itself using purely the Embedded Host Client. This would keep things simple and not require things like SSH to be enabled on the ESXi host.

After a bit of brainstorming with Etienne, he actually found a super clever way of accomplishing this after our conversation. The idea I had was to make use of the ESXi Datastore to store the VIB which can be uploaded through the Embedded Host Client. By default, there is also an HTTP based interface to the datastore, however it requires authentication which would be a problem. The neat idea that was suggested was why not try to specify the local VMFS path to the ESXi VIB (e.g./vmfs/volumes/datastore1/my.vib)? It turns out that this actually works as well!

With just two easy steps, you can now upload an ESXi VIB and then install/update all using just the Embedded Host Client with no additional dependencies

Step 1 - Navigate to the Datastore section in the Embedded Host Client and then upload the ESXi VIB that you wish to install or update.

Step 2 - To install/update the VIB, click on Help in the upper right hand corner of the Embedded Host Client and select the "Update" option. Specify the local VMFS path to ESXi VIB and then click on Update to apply.

Note: A reboot may be required after applying a new VIB. It will be your responsibility to shutdown the VMs and reboot the ESXi host for changes to go into effect if required.

At this point, you should also see a task kicked off applying the VIB. If there are any errors thrown, they will be displayed else you should see a successful task completion. For educational purposes, here is a quick screenshot of /var/log/esxupdate.log showing the VIB being applied, this can be used for further troubleshooting if required.

Hope you enjoyed this neat little trick and with just two easy steps you can install or update any ESXi VIB using the Embedded Host Client without additional dependencies or enabling SSH on the ESXi host.

How to create a custom ESXi VIB to execute a script once?

07.16.2015 by William Lam // 14 Comments

Earlier this week I received a question from a customer who was interested in creating a custom ESXi VIB that could execute a specific script within the payload as part of the installation and only running it once. This was a fairly common request that I have seen in the past and as far as I knew, this type of behavior was not possible. What was unique about this particular custom inquiry was that they mentioned they found some references on this being possible. Being the curious person I am, I decided to take another look and reach out to a few folks in Engineering.

After speaking with one of the Engineers familiar with our VIB specification, to my surprise I learned that this type of behavior was actually indeed possible but was not very well documented externally. The typical use case for this is usually to apply certain configurations which are not exposed through the traditional ESXi interfaces like the vSphere API/CLI which includes Host Profiles. One example that comes to mind is being able to deploy a VIB across several hundred ESXi hosts that could configure a specific ESXi Advanced Setting which might be marked hidden. Another example would be updating a configuration file like /etc/vmware/config or running a series of ESXi Shell commands which can not available in the vSphere API and require the use of SSH and the ESXi Shell. There are many other examples, but this should give you an idea of some of the common use cases that I have heard from customers.

Here is what is required to execute a specific script as part of the VIB installation:

Created an "init" script which needs to be stored under /etc/init.d as part of your VIB payload (e.g. /etc/init.d/lamw-special-vib)
You must ensure that the "live-install-allowed" param is set to true in your VIB's descriptor.xml file (this assumes the changes can be applied without requiring reboot to take affect)
The init script will need to parse special keywords passed as command-line arguments

Here is a table showing the pair of special keywords that are passed to the init script as command-line arguments during a VIB install, upgrade or remove:

Arg1	Arg2	VIB Operation
start	install	VIB install
start	upgrade	VIB upgrade
stop	remove	VIB removal

It is up to creator of the init script to handle the different VIB operations by parsing the command-line arguments which would then determine the operations that would get executed within the script. This not only allows you to control the commands that are executed during an installation of a VIB but it also allows you specify the commands to run upon the removal of a VIB which is quite handy for properly cleaning up an uninstall. In addition, since these special keywords are not passed as part of the ESXi boot up process, the commands within the script will not execute and ensures it only runs once during the install.

Here is very simple shell script (you could also do this in Python as well) which demonstrates how to handle the three different types of VIB operations and then uses the "logger" utility to write some output to syslog:

#!/bin/sh

ARG1=$1
ARG2=$2

if [[ "${ARG1}" == "start" ]] && [[ "${ARG2}" == "install" ]]; then
 # commands to run go here #
 /bin/logger "William's custom script ran on start-install"
elif [[ "${ARG1}" == "start" ]] && [[ "${ARG2}" == "upgrade" ]]; then
 /bin/logger "William's custom script ran on start-upgrade"
 # commands to run go here #
elif [[ "${ARG1}" == "stop" ]] && [[ "${ARG2}" == "remove" ]]; then
 /bin/logger "William's custom script ran on stop-remove"
 # commands to run go here #
fi

As you can see, this allows you to perform a variety of tasks through the use of a custom ESXi VIB which is a great way to be able to roll out a set of changes that may not be possible using either the vSphere API or Host Profiles for example. Best of all, this solution does not require the use of SSH which is great since many customers already disable this by default.

For more information on creating a custom VIB, be sure to check out my blog post here and you can even use this Docker image I created for building custom ESXi VIBs.