Iteration through RestAPI POST calls - rest

Question

I'm working with a private cloud platform that is used for creating and testing Virtual Machines. They have rich API which allows me to create VMs:
{
"name": "WIN2016-01",
"description": "This is a new VM",
"vcpus": 4,
"memory": 2147483648,
"templateUuid": "sdsdd66-368c-4663-82b5-dhsg7739smm",
...
}
I need to automate this process of creating machines by just simply iterating -01 part, so it becomes:
"name": "WIN2016-01",
"name": "WIN2016-02",
"name": "WIN2016-03"
etc.
I tried to use Postman Runner and build the workflow https://learning.getpostman.com/docs/postman/collection_runs/building_workflows/ but with no luck - not sure what syntax I need to use in Tests tab.

Answer 1

This is one way of doing it.
Create a collection and your POST request.
In your pre-request, add the following:
/* As this will be run through the Collection Runner, this extracts
the number of the current iteration. We're adding +1, as the iteration starts from 0.*/
let count = Number(pm.info.iteration) + 1;
//Convert the current iteration number, to a '00' number format (will be a string)
let countString = ((count) < 10) ? '0' + count.toString() :
count.toString();
//Set an environment variable, which can be used anywhere
pm.environment.set("countString", countString)
In your POST request body, do something like this:
{
"name": "WIN2016-{{countString}}",
...
}
Now, run your collection through the 'Collection Runner', and enter the number of Iterations (e.g. how many times you want your collection to run). You can also add a Delay, if your API imposes rate limits.
Finally, click Run.