vExpert 2011 - Christian Johannsen

Over the last two years I tried to become a so called VMware "vExpert". This award is really important to me cause it indicates what I have done for the community in the last years. As blog author, author of several white-paper and virtualization evangelist (virtual automation cult) this is a real honor.

So, thanks folks! :)

vCO - OUT-parameter serialization with JSON

Today I stumbled again delivering OUT-parameters with vCO. There is a main thing you have to know: vCO can´t serialize objects. So it isn´t easy to deliver key-paired values to external interfaces, cause if you use "Object" and "Any" as output you`ll get some errors.

Discussing this with some smart guys at the customer site they came up with a JSON description in the "Developers Guide" which is used for WebView. Typically I put all information in a nested Array/string to generate a machine readable output, but JSON could be an alternative.

I started searching with the API Explorer for "JSON" and I found one action:

•  objectToJson (includes the "serialize" action)

what describes exactly what I want to do.

So here is a little example vm(VC:VirtualMachine) ist IN-Parameter, param(string) is OUT-parameter:

var Specs = new Object();




Specs["vmName"] = vm.name;

Specs["vmId"] = vm.id;

Specs["vmNumCpus"] = vm.summary.config.numCpu;

Specs["vmMemorySize"] = vm.summary.config.memorySizeMB; 

Specs["vmPowerState"] = vm.runtime.PowerState.value;

Specs["vmIpAddress"] = vm.guest.ipAddress;

Specs["vmMacAddress"] = NicObject.macAddress;

Specs["vmGuestHeartbeatStatus"] = vm.summary.quickStats.guestHeartbeatStatus.value;

Specs["vmGuestMemoryUsage"] = vm.summary.quickStats.guestMemoryUsage;

Specs["vmOverallCpuUsage"] = vm.summary.quickStats.overallCpuUsage;

Specs["vmUptime"] = vm.summary.quickStats.uptimeSeconds/3600;

for(i in vm.guest.disk){

if(vm.guest.disk.capacity != undefined){

System.log(vm.guest.disk.capacity);

Specs["vmDiskCapacity"] = vm.guest.disk.capacity;

}

else{

Specs["vmDiskCapacity"] = "undefined";

}

if(vm.guest.disk.freeSpace != undefined){

System.log(vm.guest.disk.freeSpace);

Specs["vmDiskFreeSpace"] = vm.guest.disk.freeSpace;

}

else{

Specs["vmDiskFreeSpace"] = "undefined";

}

}




param = System.getModule("com.vmware.web.webview").objectToJson(Specs) ;

The easiest way to validate the code is JSONlint (http://jsonlint.com). Please keep in mind that the JSON definition does not know "undefined" as type (http://en.wikipedia.org/wiki/JSON). So you need to catch it up and change it into a string or sort it out.

Hope this helps.