Perl version of this python servicenow script posting a file - rest

Question

So I am going over the Attachment API for ServiceNow, documented here:
https://docs.servicenow.com/integrate/inbound_rest/reference/r_AttachmentAPI-POST.html
For an application I'm working on, I need to write up some Perl code to handle attachments. Unfortunately, the ServiceNow Perl API libraries do not handle attachments larger than 5mb, so I need to use the stock Attachment API that comes with the instance.
From the above link, I saw this example on how to post files with this python code.
#Need to install requests package for python
#easy_install requests
import requests
# Set the request parameters
url = 'https://instance.service-now.com/api/now/attachment/file?table_name=incident&table_sys_id=d71f7935c0a8016700802b64c67c11c6&file_name=Issue_screenshot.jpg'
# Specify the file To send. When specifying fles to send make sure you specify the path to the file, in
# this example the file was located in the same directory as the python script being executed.
data = open('Issue_screenshot.jpg', 'rb').read()
# Eg. User name="admin", Password="admin" for this code sample.
user = 'admin'
pwd = 'admin'
# Set proper headers
headers = {"Content-Type":"image/jpeg","Accept":"application/json"}
# Do the HTTP request
response = requests.post(url, auth=(user, pwd), headers=headers, data=data)
# Check for HTTP codes other than 201
if response.status_code != 201:
print('Status:', response.status_code, 'Headers:', response.headers, 'Error Response:',response.json())
exit()
# Decode the JSON response into a dictionary and use the data
data = response.json()
print(data)
I've used REST::Client a lot for posting, but unfortunately, I can't find a good example on how to handle the above ^^ but in Perl. How does one use REST::Client to post a file like above?
I've done a temp workaround with this by invoking curl in my scripts, but using REST::Client would be more elegant.

Answer 1

You can use LWP::UserAgent Perl module to achieve the same:
#!/usr/bin/perl
use strict;
use warnings;
use LWP::UserAgent;
use HTTP::Request;
use Fcntl;
use JSON qw[decode_json];
use Data::Dumper;
my $ua = LWP::UserAgent->new;
my $url = 'https://instance.service-now.com/api/now/attachment/file?table_name=incident&table_sys_id=d71f7935c0a8016700802b64c67c11c6&file_name=Issue_screenshot.jpg';
my $user = 'admin';
my $pwd = 'admin';
$ua->credentials( 'instance.service-now.com', '<REALM>', $user, $pwd);
my $file = 'Issue_screenshot.jpg';
my $request = HTTP::Request->new( POST => $url );
$request->header( 'Content-Type' => 'image/jpeg');
$request->header( 'Accept' => 'application/json');
$request->header( 'Content-Length' => -s $file);
sysopen(my $fh,$file,O_RDONLY);
$request->content( sub {
sysread($fh,my $buf,1024);
return $buf;
});
my $res = $ua->request($request);
unless($res->code == 201) {
print 'Status: '.$res->code, 'Headers:',$res->headers_as_string,'Error Response:',$res->content;
exit;
}
my $data = decode_json($res->content);
print Dumper($data);