Make dynamic request using Gatling - scala

Question

I want to make a dynamic request using Gatling.
using Gatling we are getting to rest-API to which we are posting an SMS request I want that each request should be done with a different sent of mob no.
exec(http("Sms Delivery")
.post(s"/deliveries")
.body(StringBody(
s"""{ "template":
|{ "type":"inline", "inline":
| { "channels":
| "sms":{ "body":{ "layout":"{greeting}", "fragments":{ "greeting":{"en-US":"ABC123 Interested to hear about some jobs?"}}}} }} },
| "recipients":[ { "contactDetails":{ "mobileNumber" : "+1${Random.nextInt(123123123)}" } }],
| "requester": "${UUID.random.toString}"}""".stripMargin)).asJson
.check(status.is(202))
.check(jsonPath("$.messageId").ofType[String])
)
}
setUp(
scenario("Create message-Cmd")
.exec(createMessageServiceSms()).inject(
rampConcurrentUsers(0) to (6) during(1),
constantConcurrentUsers(5) during (testTime seconds)
)
)
Let suppose Gatling sends 100 requests the for all those requests my mob no remains the same for each request is same let say [phone].
However, I want all no. should be different.

Answer 1

The string is created only once, then parsed as Expression Language, which allows you to substitute in session attributes.
If you want custom functions like creating a UUID and calling Random.nextInt, you need to pass in a function to StringBody.
StringBody(_ =>
s"""{ "template":
|{ "type":"inline", "inline":
| { "channels":
| "sms":{ "body":{ "layout":"{greeting}", "fragments":{ "greeting":{"en-US":"ABC123 Interested to hear about some jobs?"}}}} }} },
| "recipients":[ { "contactDetails":{ "mobileNumber" : "+1${Random.nextInt(123123123)}" } }],
| "requester": "${UUID.random.toString}"}""".stripMargin)
)
The parameter that we discarded is the virtual user's Session.
Worth noting that you may have too few digits for the mobileNumber, but that's another issue than creating a dynamic request.