import requests, lxml.html

s = requests.session()
login = s.get('http://localhost:8090/index.php')
login_html = lxml.html.fromstring(login.text)
hidden_inputs = login_html.xpath(r'//form//input[@type="hidden"]')
form = {x.attrib["name"]: x.attrib["value"] for x in hidden_inputs}


#print (s.cookies)
#print(form)

form['login_name'] = 'glpi'
form['login_password'] = 'glpi'

headers = {
    'Host': 'localhost:8090',
    'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:54.0) Gecko/20100101 Firefox/54.0',
    'Accept': '*/*',
    'Accept-Language': 'en-US,en;q=0.5',
    'X-Requested-With': 'XMLHttpRequest',
    'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
    'Referer': 'http://localhost:8090/login.php',
    'DNT': '1',
    'Connection': 'keep-alive',
    'Pragma': 'no-cache',
    'Cache-Control': 'no-cache',
}

response = s.post('http://localhost:8090/front/central.php', headers=headers, data=form)

headers = {
    'Host': 'localhost:8090',
    'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:54.0) Gecko/20100101 Firefox/54.0',
    'Accept': '*/*',
    'Accept-Language': 'en-US,en;q=0.5',
    'X-Requested-With': 'XMLHttpRequest',
    'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
    'Referer': 'http://localhost:8090/front/ticket.form.php?id=1',
    'DNT': '1',
    'Connection': 'keep-alive',
    'Pragma': 'no-cache',
    'Cache-Control': 'no-cache',
}

data = [
  ('target', '/front/ticket.form.php'),
  ('itemtype', 'Ticket'),
  ('glpi_tab', 'TicketTask$1'),
  ('id', '1'),
  ('template_preview', '0'),
]

response = requests.post('http://localhost:8090/ajax/common.tabs.php', headers=headers, data=data)
# O usando la cookie mas explicita:
#
#   response = requests.post('http://localhost:8090/ajax/common.tabs.php', headers=headers, coockies=cookies, data=data)
#
# Si en el request envio las cookies como
#   cookies = {
#    'PHPSESSID':  s.cookies['PHPSESSID'],
#   }
#
#  Tampoco funciona.

print (response.text)