Welcome!

Open Source Cloud Authors: Pat Romanski, Liz McMillan, Elizabeth White, Wesley Coelho, Rainer Ersch

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
"We are focused on SAP running in the clouds, to make this super easy because we believe in the tremendous value of those powerful worlds - SAP and the cloud," explained Frank Stienhans, CTO of Ocean9, Inc., in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
The financial services market is one of the most data-driven industries in the world, yet it’s bogged down by legacy CPU technologies that simply can’t keep up with the task of querying and visualizing billions of records. In his session at 20th Cloud Expo, Karthik Lalithraj, a Principal Solutions Architect at Kinetica, discussed how the advent of advanced in-database analytics on the GPU makes it possible to run sophisticated data science workloads on the same database that is housing the rich...
SYS-CON Events announced today that Massive Networks will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Massive Networks mission is simple. To help your business operate seamlessly with fast, reliable, and secure internet and network solutions. Improve your customer's experience with outstanding connections to your cloud.
Everything run by electricity will eventually be connected to the Internet. Get ahead of the Internet of Things revolution and join Akvelon expert and IoT industry leader, Sergey Grebnov, in his session at @ThingsExpo, for an educational dive into the world of managing your home, workplace and all the devices they contain with the power of machine-based AI and intelligent Bot services for a completely streamlined experience.
DX World EXPO, LLC., a Lighthouse Point, Florida-based startup trade show producer and the creator of "DXWorldEXPO® - Digital Transformation Conference & Expo" has announced its executive management team. The team is headed by Levent Selamoglu, who has been named CEO. "Now is the time for a truly global DX event, to bring together the leading minds from the technology world in a conversation about Digital Transformation," he said in making the announcement.
Internet of @ThingsExpo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devic...
"The Striim platform is a full end-to-end streaming integration and analytics platform that is middleware that covers a lot of different use cases," explained Steve Wilkes, Founder and CTO at Striim, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
SYS-CON Events announced today that Calligo, an innovative cloud service provider offering mid-sized companies the highest levels of data privacy and security, has been named "Bronze Sponsor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Calligo offers unparalleled application performance guarantees, commercial flexibility and a personalised support service from its globally located cloud plat...
SYS-CON Events announced today that DXWorldExpo has been named “Global Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Digital Transformation is the key issue driving the global enterprise IT business. Digital Transformation is most prominent among Global 2000 enterprises and government institutions.
SYS-CON Events announced today that Datera, that offers a radically new data management architecture, has been named "Exhibitor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Datera is transforming the traditional datacenter model through modern cloud simplicity. The technology industry is at another major inflection point. The rise of mobile, the Internet of Things, data storage and Big...
While the focus and objectives of IoT initiatives are many and diverse, they all share a few common attributes, and one of those is the network. Commonly, that network includes the Internet, over which there isn't any real control for performance and availability. Or is there? The current state of the art for Big Data analytics, as applied to network telemetry, offers new opportunities for improving and assuring operational integrity. In his session at @ThingsExpo, Jim Frey, Vice President of S...
"We provide IoT solutions. We provide the most compatible solutions for many applications. Our solutions are industry agnostic and also protocol agnostic," explained Richard Han, Head of Sales and Marketing and Engineering at Systena America, in this SYS-CON.tv interview at @ThingsExpo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"We've been engaging with a lot of customers including Panasonic, we've been involved with Cisco and now we're working with the U.S. government - the Department of Homeland Security," explained Peter Jung, Chief Product Officer at Pulzze Systems, in this SYS-CON.tv interview at @ThingsExpo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"MobiDev is a Ukraine-based software development company. We do mobile development, and we're specialists in that. But we do full stack software development for entrepreneurs, for emerging companies, and for enterprise ventures," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
SYS-CON Events announced today that DXWorldExpo has been named “Global Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Digital Transformation is the key issue driving the global enterprise IT business. Digital Transformation is most prominent among Global 2000 enterprises and government institutions.
In his opening keynote at 20th Cloud Expo, Michael Maximilien, Research Scientist, Architect, and Engineer at IBM, discussed the full potential of the cloud and social data requires artificial intelligence. By mixing Cloud Foundry and the rich set of Watson services, IBM's Bluemix is the best cloud operating system for enterprises today, providing rapid development and deployment of applications that can take advantage of the rich catalog of Watson services to help drive insights from the vast t...
SYS-CON Events announced today that EnterpriseTech has been named “Media Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. EnterpriseTech is a professional resource for news and intelligence covering the migration of high-end technologies into the enterprise and business-IT industry, with a special focus on high-tech solutions in new product development, workload management, increased effic...
SYS-CON Events announced today that Massive Networks, that helps your business operate seamlessly with fast, reliable, and secure internet and network solutions, has been named "Exhibitor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. As a premier telecommunications provider, Massive Networks is headquartered out of Louisville, Colorado. With years of experience under their belt, their team of...
SYS-CON Events announced today that Cloud Academy named "Bronze Sponsor" of 21st International Cloud Expo which will take place October 31 - November 2, 2017 at the Santa Clara Convention Center in Santa Clara, CA. Cloud Academy is the industry’s most innovative, vendor-neutral cloud technology training platform. Cloud Academy provides continuous learning solutions for individuals and enterprise teams for Amazon Web Services, Microsoft Azure, Google Cloud Platform, and the most popular cloud com...
SYS-CON Events announced today that Cloudistics, an on-premises cloud computing company, has been named “Bronze Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Cloudistics delivers a complete public cloud experience with composable on-premises infrastructures to medium and large enterprises. Its software-defined technology natively converges network, storage, compute, virtualization, and ...