How to specify number of instances of a machine via REST API

[jason_davis]

I am using the following vRA Rest API's to provision a blueprint

template = Get  ("/catalog-service/api/consumer/entitledCatalogItems/" + catalogID + "/requests/template");

Post ("/catalog-service/api/consumer/entitledCatalogItems/" + entitledCatalogID + "/requests", template.ToString())

It works fine.

Now I am trying to specify the # of instances of a given machine within the template.

By default the number of instances is set to 1, like so:

{

  "type": "com.vmware.vcac.catalog.domain.request.CatalogItemProvisioningRequest",

  "catalogItemId": "2c79ed7e-30d7-4ff3-8d38-bb790d62b405",

  "requestedFor": "xyz",

  "businessGroupId": "6538a56e-9986-42c8-82d1-4a55f267654c",

  "description": null,

  "reasons": null,

  "data": {

....

    },

    "_leaseDays": 1,

   "_number_of_instances": 1

  }

If I change that to anything other than 1, I get the following error:

{ "errors": [ { "code": 20117, "source": null, "message": "The data specified within the request is invalid.", "systemMessage": "The data specified within the request is invalid.", "moreInfoUrl": null }, { "code": 11003, "source": null, "message": "The value of the '_number_of_instances' field cannot be more than 1.", "systemMessage": "The value of the field with id _number_of_instances cannot be more than 1.", "moreInfoUrl": null } ] }

even though my blueprint allows # of machines to be more than 1

Can the API support this capability?

[jason_davis]

So I found the answer in a different post:

VRA 7.1 What is the JSON content to request multiple instances in a deployment

Now, I am going to be greedy.  Is there any way to set the # of instances of a machine to ZERO?  I have blueprints with multiple machine types.  In order to save resource, I would like the ability programmatically to set ZERO for certain machines if requested by my user.  So far I cannot seem to set _cluster = 0.

I get this error:

<The value of the '_cluster' field cannot be less than 1>

If anyone has a suggestion how to do this, it would be appreciated.

[daphnissov · Accepted solution]

You cannot set number of instances to zero if you have an object on the blueprint canvas, otherwise that object would essentially be null.

[jason_davis]

Hi Daphnissov,

Thanks for clarifying. 

I have a blueprint with over 20 different machine types,  and I was hoping there could be some workaround to disable some machines from being created when they are not needed by the requesting user.  I guess the best I can do is to turn the machine off and/or destroy it via vCenter API after it gets created.  That will free up some resource.

Cheers,

Jason

[daphnissov]

I think there are better ways to go about achieving what I believe your goal is, but they all don't include having 20 different machines types in one blueprint. I don't know what you're trying to do here, but you'll want to apply some sort of logic-based selection (wherever that needs to be) which choose the right blueprint for the right condition. If that's in an external CI tool then great.

[jason_davis]

We are creating virtual 'labs' where test teams can collaborate on a common testing mission.   The machines within the deployment are connected and may interact with each other.

Some test missions are large which require a full deployment of machines, and others are more narrow and focussed.

I don't want to create a different blueprint type for each size test lab.  So I plan to create a FULL lab, but allow users to make smaller labs when needed to save space in the data center.

In any case I think there are some options, so we can make it work.

Thanks again for the feedback