Python API: Acces to iRODS data through tickets

[Christine Staiger]

Dear all,

we are currently investigating temporary access to data for the anonymous user. I stumbled over the tickets which do exactly what we need. Unfortunately I could only setup the data access under linux/icommands. Is there a way to also access data behind a ticket as the anonymous user with the python API?

Many thanks for your help and kind regards,

Christine Staiger

[dmoore.renci]

hello Christine,

Here is useticket.py, an example of supplying an existing ticket for use with a session in the Python iRODS Client:

from __future__ import print_function
import os, sys, getopt
from irods.test.helpers import make_session
import irods.ticket
from irods.session import iRODSSession

with iRODSSession( user='anonymous',password='',zone='tempZone',port=1247,host='localhost') as ses:

    tck = irods.ticket.Ticket(ses, os.environ.get('TICKET'))
    if tck is None:
        print('Please supply ticket string as env variable TICKET',file=sys.stderr); exit(2)

    tck.supply()   # - activate the ticket

    opts,args = getopt.getopt(sys.argv[1:],'rw:')
    opt=dict(opts)
    object_name = args[0]

    if '-w' in opt:
        dta = ses.data_objects.open(object_name,'r+') # append the -w value's content to the data object
        dta.seek(0,2)
        dta.write(opt['-w'].encode())
    elif '-r' in opt:
        dta = ses.data_objects.open(object_name,'r')  # read and print out the data object
        print(dta.read(99999).decode())
    else:
        print("must specify -r or -w.",file=sys.stderr); exit(3)
    dta.close()

You can see this in action by 'PUT'ting a file as the rods admin and generating read and write tickets for it:

irods:~$  iput -f VERSION.json

irods@69059138e9ff:~$ iticket create write /tempZone/home/rods/VERSION.json
ticket:Vmlz2InpZsHoKgC
irods@69059138e9ff:~$ iticket create read /tempZone/home/rods/VERSION.json
ticket:T9IOm0RbmxAiI9y

Then as a different user logged in as anonymous on iRODS :

anon@69059138e9ff:~$ TICKET=Vmlz2InpZsHoKgC python useticket.py -w 'SOME TEXT TO APPEND' /tempZone/home/rods/VERSION.json
anon@69059138e9ff:~$ TICKET=T9IOm0RbmxAiI9y python useticket.py -r /tempZone/home/rods/VERSION.json
{
    "catalog_schema_version": 8,
    "commit_id": "f615a350dc0b787e9140a61c501fdd7e765b40dc",
    "configuration_schema_version": 3,
    "installation_time": "2021-10-08T12:31:29.146408",
    "irods_version": "4.2.10"
}
SOME TEXT TO APPEND

So, as you can see, we've just used one ticket that grants WRITE access (here, an append) text to a data object and printed it out with a different ticket granting READ.

Using a ticket for the wrong purpose will raise an irods exception with code CAT_TICKET_INVALID.

thanks,

 -- Daniel Moore - Applications ENgineer - iRODS Consortium

[Christine Staiger]

Dear Daniel,

many thanks for you quick reply and help!

Kind regards,

Christine