Welcome!

Open Source Cloud Authors: Elizabeth White, Pat Romanski, Rostyslav Demush, Yeshim Deniz, Harry Trott

Blog Feed Post

vCloud Automation Center – vCAC 5.1 – Executing Scripts with the Linux Guest Agent

I’ve been getting asked a lot of question on how to execute scripts within Linux Guest Systems using vCAC. There are a few components to executing scripts in a Linux Guest OS which I’m going to cover in this post. Those items are:

  • Linux Guest Agent
  • Custom Properties

Linux Guest Agent

The Linux guest agent has a number of feature benefits that you receive if you utilize it. The Linux guest agent is a small agent that acts very similarly to the vCAC proxy agents. When it is installed you give it the name or IP address of the vCAC server. This allows it to check in with the server when it loads on a newly provisioned machine and determine if there is anything it needs to do. If the vCAC server has work for it to do it send the instructions and the agent executes the instructions on the local guest operating system. The guest agent comes with a number of pre-built scripts and functions, but also allows you to execute your own scripts. Some of the features available with the Linux Guest Agent are:

  • Disk Operations – Partition, Format, and mount disk that is added to the machine.
  • Execute Scripts – Execute scripts after the machine is provisioned.
  • Network Operations – Configure setting for additional network interfaces added to the machine.


This article is primarily about executing scripts with the guest agent, however by installing the guest agent if you add a disk and define the proper paramaters you will be able to utilize the Disk Operations that it supports. I will discuss networking in more details in a different article.
 

Installing the Guest Agent

1. You will need to install the Linux Guest Agent in your VMware Template that you will be using. In my example I’m using Centos 6.3 x64.
 
2. You will need to get the agent into your template either by accessing it across the network or by putting it on an ISO and mounting it to the VM. The agent are part of the vCAC installation package and are located under “LinuxGuestAgentPkgs” there you will find agents for a number of flavors of Linux.
 
3. Once you have your agent on your template you need to install the agent package. There are generally two packages, a tar.gz as well as a RPM. I will be installing the rpm file for rhel6-amd64. The specific package name is “gugent-5.1.1-56.x86_64.rpm”.
 
4. Install the package by doing the following: rpm -ivh path/gugent-5.1.1-56.x86_64.rpm. In the below image mine was already installed, but you get the idea.
vcaclgas-1
5. Next we need to execute the agent installer. You need to go to /usr/share/gugent and run ./installgugent.sh {vcac server} you can use either the IP address of hostname of the vCAC server.
vcaclgas-2
6. You can verify the proper name/IP by doing “cat rungugent.sh” and looking at the “–host=” statement on the 6th line.
vcaclgas-3
7. We next need to rename one of the scripts that is included with the Linus Guest Agent due to a bug. Navigate to “/usr/share/gugent/site/CustomizeGuestOS” In this folder you will see a script named “20_static_ip.sh” this script is depreciated and not needed. Rename the script to “old_20_static_ip.sh” by doing “mv 20_static_ip.sh old_20_static_ip.sh“.
vcaclgas-4
8. If you want to follow the example that I will be giving you should also create a folder on the template to be utilized as a mount point for an NFS share. I created “/Scripts” and my mount point by doing “mkdir /Scripts“.
 
9. Next I created a helper script in the template that I will use to mount my NFS share. I placed my script in the root of the disk, but you can place it where ever you like. A good place for it would be in “/usr/share/gugent/site/CustomizeOS“, but it really doesn’t matter where you place it.
 
10. My script is named “repomount.sh” and looks like this: “mount -t nfs $1 /Scripts” nothing fancy at all.
 
11. Once you have the script created go ahead and “shutdown” your template machine and “Convert it to a template” in “vCenter“.
 

Configure vCAC

12. If this is a “new template” that you just created you will need to “manually” perform a “Data Collection” in “vCAC“. You can do this by navigating to “Enterprise Administrator” Selecting “Compute Resources” and hover over the cluster that the template exists in and then select “Data Collection” Once there click “Request Now” under “Inventory“.
 
13. Once the “Data Collection” is complete your “template” will be ready for use.
 
14. If you don’t already have a blueprint that can deploy this “template” you will need to create one. See my article on “Connecting to vCenter” for instructions on creating a blueprint.
 
15.Next we are going to create a “Build Profile” that we can use to hold our properties. Navigate to “Enterprise Administrator” and select “Build Profiles” then select “New Build Profile“.
16. Give the “Build Profile” a “Name” and then we are going to add some “Custom Properties” to the profile. We need to add the following properties and values:

  • repo.path – This is a property that I made up for this example. It is not part of vCAC. The value should the the path to your “NFS” share in the format “IP:/volume/share” This is what we are going to mount to the folder we created earlier
  • VirtualMachine.Admin.UseGuestAgent – This tells vCAC to utilize the guest agent as part of the deployment process. The “value” should be “true“.
  • VirtualMachine.Customize.WaitComplete – This tells vCAC to wait until the vCenter Guest Customization is complete. If you do not use “Customization Specifications” you do not need this property. The “value” should be “true” if you use vCenter guest customization.
  • VirtualMachine.Software0.Name – Assign a name for the script you are going to execute. “Value” is a “Friendly Name” for your script.
  • VirtualMachine.Software0.ScriptPath – Path to your script including the script name. You can pass parameters to your script as well. I’m passing the value for the “repo.path” that I created earlier to my script to be utilizing as the “NFS location” to mount. The value is “/repomount.sh {repo.path}“. Note: The {} brackers are required in the value.
  • VirtualMachine.Software1.Name – I’m executing a second script so I’ve used the “VirtualMachine.Software1.Name” property again only with a 1 instead of a 0 this time.
  • VirtualMachine.Software1.ScriptPath – I’m executing a second script. This one s located on the NFS share that I am mounting with my first script. My script is “BashScript.sh” and it contains “echo “The script was successfully executed” > /Script_Successfull.txt

17. Click “Ok” to save the “Build Profile
vcaclgas-5
18. Next we need to assign this build profile to our “Linux Blueprint“. Go to “Enterprise Administrator” select “Global Blueprints“, then select the “Linux Blueprint” and then “edit“.
 
10. Once the “Blueprint” opens select the “Properties” tab and select the “Build Profile” you just created and then click “Ok
vcaclgas-6

So what does all this do

When you request a machine custom properties are associated with the machine. Some custom properties are what we call reserved properties because vCAC understands them and performs actions based on them. The “VirtualMachine.Admin.UseGuestAgent” property tells vCAC that when the machine is provisioning it needs to create workitems for the “Linux Guest Agent” to pick up. The “VirtualMachine.SoftwareX.Name” and “Virtualmachine.SoftewareX.ScriptPath” are put into the work item that is created by vCAC to instruct the ‘Linux Guest Agent” to execute those scripts.
 
In this example the first script will execute and mount the NFS share that I defined my my own property “repo.path”. Once complete the second script will run and execute “BashScript.sh” which will create a txt file. The guest agent performs it’s tasks after the VMware Guest Customization if being utilized otherwise it completed it after the “Machine Provisioned” state. Once the Linux Agent completed all it’s work items it will then remove itself from loading on future loads and stop it’s service.

Read the original blog entry...

More Stories By Sidney Smith

Sid Smith, founder of DailyHypervisor is considered to be a cloud expert in the IT field with over 10 years experience in Virtualization, Automation, and Cloud technologies. Sid Smith started in the industry designing and implementing large scale enterprise server and desktop virtualization environments for fortune 100 and 500 companies. He later went on to become a key employee at DynamicOps the well know creators of Cloud Automation Center. In July 2012 DynamicOps was acquired by VMware who has adopted Cloud Automation Center as a center piece for it’s vCloud Suite of products. Sid has helped dozens of fortune 100 and 500 enterprises successfully adopt both private and public cloud strategies as part of their IT offerings. The result of which was large operational and capital savings for his customers. Sid continues to help large enterprise customers reach their hybrid cloud strategies at VMware. On DailyHypervisor you will find exclusive content that will help you learn how to adopt a successful cloud strategy through the use of VMware Cloud Automation Center, Open Stack, and other industry recognized cloud solutions.

@ThingsExpo Stories
DXWorldEXPO LLC announced today that All in Mobile, a mobile app development company from Poland, will exhibit at the 22nd International CloudEXPO | DXWorldEXPO. All In Mobile is a mobile app development company from Poland. Since 2014, they maintain passion for developing mobile applications for enterprises and startups worldwide.
Digital Transformation is much more than a buzzword. The radical shift to digital mechanisms for almost every process is evident across all industries and verticals. This is often especially true in financial services, where the legacy environment is many times unable to keep up with the rapidly shifting demands of the consumer. The constant pressure to provide complete, omnichannel delivery of customer-facing solutions to meet both regulatory and customer demands is putting enormous pressure on...
The best way to leverage your CloudEXPO | DXWorldEXPO presence as a sponsor and exhibitor is to plan your news announcements around our events. The press covering CloudEXPO | DXWorldEXPO will have access to these releases and will amplify your news announcements. More than two dozen Cloud companies either set deals at our shows or have announced their mergers and acquisitions at CloudEXPO. Product announcements during our show provide your company with the most reach through our targeted audienc...
IoT is at the core or many Digital Transformation initiatives with the goal of re-inventing a company's business model. We all agree that collecting relevant IoT data will result in massive amounts of data needing to be stored. However, with the rapid development of IoT devices and ongoing business model transformation, we are not able to predict the volume and growth of IoT data. And with the lack of IoT history, traditional methods of IT and infrastructure planning based on the past do not app...
"Akvelon is a software development company and we also provide consultancy services to folks who are looking to scale or accelerate their engineering roadmaps," explained Jeremiah Mothersell, Marketing Manager at Akvelon, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
IoT is rapidly becoming mainstream as more and more investments are made into the platforms and technology. As this movement continues to expand and gain momentum it creates a massive wall of noise that can be difficult to sift through. Unfortunately, this inevitably makes IoT less approachable for people to get started with and can hamper efforts to integrate this key technology into your own portfolio. There are so many connected products already in place today with many hundreds more on the h...
More and more brands have jumped on the IoT bandwagon. We have an excess of wearables – activity trackers, smartwatches, smart glasses and sneakers, and more that track seemingly endless datapoints. However, most consumers have no idea what “IoT” means. Creating more wearables that track data shouldn't be the aim of brands; delivering meaningful, tangible relevance to their users should be. We're in a period in which the IoT pendulum is still swinging. Initially, it swung toward "smart for smart...
DXWorldEXPO LLC, the producer of the world's most influential technology conferences and trade shows has announced the 22nd International CloudEXPO | DXWorldEXPO "Early Bird Registration" is now open. Register for Full Conference "Gold Pass" ▸ Here (Expo Hall ▸ Here)
As data explodes in quantity, importance and from new sources, the need for managing and protecting data residing across physical, virtual, and cloud environments grow with it. Managing data includes protecting it, indexing and classifying it for true, long-term management, compliance and E-Discovery. Commvault can ensure this with a single pane of glass solution – whether in a private cloud, a Service Provider delivered public cloud or a hybrid cloud environment – across the heterogeneous enter...
The Jevons Paradox suggests that when technological advances increase efficiency of a resource, it results in an overall increase in consumption. Writing on the increased use of coal as a result of technological improvements, 19th-century economist William Stanley Jevons found that these improvements led to the development of new ways to utilize coal. In his session at 19th Cloud Expo, Mark Thiele, Chief Strategy Officer for Apcera, compared the Jevons Paradox to modern-day enterprise IT, examin...
DXWorldEXPO LLC announced today that ICC-USA, a computer systems integrator and server manufacturing company focused on developing products and product appliances, will exhibit at the 22nd International CloudEXPO | DXWorldEXPO. DXWordEXPO New York 2018, colocated with CloudEXPO New York 2018 will be held November 11-13, 2018, in New York City. ICC is a computer systems integrator and server manufacturing company focused on developing products and product appliances to meet a wide range of ...
Headquartered in Plainsboro, NJ, Synametrics Technologies has provided IT professionals and computer systems developers since 1997. Based on the success of their initial product offerings (WinSQL and DeltaCopy), the company continues to create and hone innovative products that help its customers get more from their computer applications, databases and infrastructure. To date, over one million users around the world have chosen Synametrics solutions to help power their accelerated business or per...
Bill Schmarzo, author of "Big Data: Understanding How Data Powers Big Business" and "Big Data MBA: Driving Business Strategies with Data Science," is responsible for setting the strategy and defining the Big Data service offerings and capabilities for EMC Global Services Big Data Practice. As the CTO for the Big Data Practice, he is responsible for working with organizations to help them identify where and how to start their big data journeys. He's written several white papers, is an avid blogge...
We are seeing a major migration of enterprises applications to the cloud. As cloud and business use of real time applications accelerate, legacy networks are no longer able to architecturally support cloud adoption and deliver the performance and security required by highly distributed enterprises. These outdated solutions have become more costly and complicated to implement, install, manage, and maintain.SD-WAN offers unlimited capabilities for accessing the benefits of the cloud and Internet. ...
Charles Araujo is an industry analyst, internationally recognized authority on the Digital Enterprise and author of The Quantum Age of IT: Why Everything You Know About IT is About to Change. As Principal Analyst with Intellyx, he writes, speaks and advises organizations on how to navigate through this time of disruption. He is also the founder of The Institute for Digital Transformation and a sought after keynote speaker. He has been a regular contributor to both InformationWeek and CIO Insight...
Join IBM November 1 at 21st Cloud Expo at the Santa Clara Convention Center in Santa Clara, CA, and learn how IBM Watson can bring cognitive services and AI to intelligent, unmanned systems. Cognitive analysis impacts today’s systems with unparalleled ability that were previously available only to manned, back-end operations. Thanks to cloud processing, IBM Watson can bring cognitive services and AI to intelligent, unmanned systems. Imagine a robot vacuum that becomes your personal assistant tha...
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
I think DevOps is now a rambunctious teenager - it's starting to get a mind of its own, wanting to get its own things but it still needs some adult supervision," explained Thomas Hooker, VP of marketing at CollabNet, in this SYS-CON.tv interview at DevOps Summit at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
Recently, WebRTC has a lot of eyes from market. The use cases of WebRTC are expanding - video chat, online education, online health care etc. Not only for human-to-human communication, but also IoT use cases such as machine to human use cases can be seen recently. One of the typical use-case is remote camera monitoring. With WebRTC, people can have interoperability and flexibility for deploying monitoring service. However, the benefit of WebRTC for IoT is not only its convenience and interopera...
Cloud-enabled transformation has evolved from cost saving measure to business innovation strategy -- one that combines the cloud with cognitive capabilities to drive market disruption. Learn how you can achieve the insight and agility you need to gain a competitive advantage. Industry-acclaimed CTO and cloud expert, Shankar Kalyana presents. Only the most exceptional IBMers are appointed with the rare distinction of IBM Fellow, the highest technical honor in the company. Shankar has also receive...