Use jira-ruby Jira API Gem to make a new issue

create_issue.rb

#!/usr/bin/env ruby

require 'jira-ruby'

options = {
  :username     => 'service-account-user',
  :password     => 'service-account-pass',
  :site         => 'https://jira.server.domain',
  :context_path => '/jira',
  :auth_type    => :basic
}

client = JIRA::Client.new(options)

issue = client.Issue.build

issue.save({
  "fields" => {
    "summary"     => "This is a summary",
    "project"     => {"key" => "PROJECT"},
    "issuetype"   => {"name" => "Story"},
    "description" => "This is a description",
  }
})

print "Issue GUI URL: "
puts "#{client.options[:site]}#{client.options[:context_path]}/browse/#{issue.key}"
print "Issue API URL: "
puts issue.self