title: Programmatically provide NiFi InvokeHTTP different certificates
body: <p>I have a requirement in Nifi where I have cycle through different HTTP<strong>S</strong> REST Endpoints and provide different certificates for some endpoints and different username / password for some other endpoints. </p>
  
  <p>I used InvokeHTTP processor to send the requests, although URL takes an expression language, I cannot setup SSLContextService with an expression. </p>
  
  <p>Alternatively, I thought on using ExecuteScript to call those Endpoints, however as <a href="https://stackoverflow.com/questions/45568861/how-to-invoke-a-remote-rest-service-in-nifi/49565862">listed here in StackOverflow post</a>; I still don't know how to programmatically call an external service through a script. </p>
  
  <p>Any help appreciated. </p>