Jenkins: Active Choices Parameter + Groovy to build a list based on REST responde - rest

Question

I have a REST client that returns me a list of systems.
I need this list to be as a parameter for a jenkins job.
I think I need Actice Choices Parameter plugin with Groovy and HTTPBuilder in order to do that.
What do you guys think?
I did not find a way to install HTTPBuilder into Jenkins.
Is there any other way that you guys think it is possible?

Answer 1

I have run into the same problem trying to parse parameters via groovy script. Arun's answer did not work for me. However, I have managed to get it to work using the following:
import java.io.BufferedReader
import java.io.InputStreamReader
import java.io.OutputStreamWriter
import java.net.URL
import java.net.URLConnection
import groovy.json.JsonSlurper
def choices = []
def url = new URL("some.data.url")
def conn = url.openConnection()
conn.setDoOutput(true)
def reader = new BufferedReader(new InputStreamReader(conn.getInputStream()))
def results = new JsonSlurper().parseText(reader.getText());
reader.close()
results.each { data -> choices.push(data.field) }
return choices.sort()

Answer 2

First paste the JSON body snapshot output -or whatever your REST client is going to return. That'll help.
For ex: if it'll return a JSON object then you can use Active Choice Parameter's Groovy script step - OR Scriptler script (within the Active Choice Parameter plugin). PS: Scriptler script runs in the same JVM of Jenkins process so it has access to Jenkins/etc object for free. You don't need HTTPBuilder or anything. See the code sample below.
Assuming if your REST client is returning a JSON object and from that object if you want to list hostname of the system or some field name then replace the following variable with that and you'll get it listed while doing "Build with parameters" from Jenkins job's dashboard.
import groovy.json.JsonSlurper
//this will be your URL which will return something, tweak it if you want to pass parameters or username/password acc.
def SOME_URL = "https://koba.baby.com/some_url"
// now connect to the URL and create a connection variable 'conn'
def conn = SOME_URL.toURL().openConnection()
// create a list variable 'servernames'
def servernames = []
// if connection response was successful i.e. http protocol return code was 200, then do the following
if( conn.responseCode == 200 ) {
// get the results / output of the URL connection in a variable 'results'
def results = new JsonSlurper().parseText(conn.content.text)
// to see results variable output uncomment the next line
//println results
// now read each element in the 'results' variable and pick servername/somefield variable into the list variable 'servernames'
results.each { id, data -> servernames.push(data.someField_or_HostName) }
}
return servernames.sort().unique()
// return servernames.sort()