How to post an API key on a header with the post() method using Groovy?

From the support docs:

Quote

post(url, payload, headers] do an HTTP POST to the provided url and return the entire response

 string url – the target url

 string payload – the post data payload

 map headers – a map containing one or more HTTP POST headers

 return string response – the entire HTTP response

It appears you want to pass a blank payload and add the X-Cisco-Meraki-API-Key header. In that case, you'll need to include a blank payload string:

import com.santaba.agent.groovyapi.http.*

ip = "api-mp.meraki.com"
url = "https://"+ip+"/api/v1/organizations/999999/appliance/vpn/statuses"
key = hostProps.get("merakiAPIKey")

httpClient = HTTP.open(ip, 443)
def postResponse = httpClient.post(url,"",["X-Cisco-Meraki-API-Key":key])

I haven't checked this, so it'd remain to be verified, but this is at least how the docs indicate it should work. I've also reordered it to be more standard and to fetch the api key from the device property (assuming you're running this as a scripted LogicModule).