NAME¶

lfc2 - New python interface to the LFC client API lfc2thr - Thread enabled version of Python interface to the LFC

SYNOPSIS¶

import lfc2 as lfc import lfc2thr as lfc lfc.init()

DESCRIPTION¶

The lfc module permits you to access the LFC client interface from python programs. The lfc module is a swig wrapping of the standard C interface. For detailed descriptions of each function see the individual man page of each function. The lfcthr module is a version of the lfc module supporting multi-threaded Python clients. Its usage is similar to the usage of the lfc module except the obligatory initialisation call lfcthr.init() in the main program before threads are started.

FUNCTIONS¶

lfc_aborttrans ( ) lfc_access ( string path, int amode ) -> bool access lfc_accessr ( string sfn, int amode ) -> bool access lfc_addreplica ( string guid, struct lfc_fileid *file_uniqueid, string server, string sfn, char status, char f_type, string poolname, string fs ) lfc_addreplicax ( string guid, struct lfc_fileid *file_uniqueid, string server, string sfn, char status, char f_type, string poolname, string fs, char r_type, string setname ) lfc_chdir ( string path ) lfc_chmod ( string path, mode_t mode ) lfc_chown ( string path, uid_t new_uid, gid_t new_gid ) lfc_client_setAuthorizationId ( uid_t uid, gid_t gid, string mech, string id ) lfc_client_setVOMS_data ( string voname, stringlist vomsdata ) lfc_closedir ( lfc_DIR dirp ) lfc_creatg ( string path, string guid, mode_t mode ) lfc_delcomment ( string path ) lfc_delete ( string path ) lfc_delfilesbyguid ( ListOfString guids, int force ) -> ListOfInt result lfc_delfilesbyname ( ListOfString names, intforce ) -> ListOfInt results lfc_delfilesbypattern ( string path, string pattern, int force ) -> ListOf struct lfc_filestatus results lfc_delreplica ( string guid, struct lfc_fileid *file_uniqueid, string sfn ) lfc_delreplicas ( ListOfString sfns, string se ) -> ListOfInt results lfc_delreplicasbysfn ( ListOfString sfns, ListOfString guids ) -> ListOfInt results lfc_endsess ( ) lfc_endtrans ( ) lfc_getacl ( string path, ) -> ListOf struct lfc_acl acls lfc_getcomment ( string path ) -> string comment lfc_getcwd ( ) -> string dir lfc_getifcevers ( ) -> string version lfc_getlinks ( string path, string guid ) -> ListOf struct lfc_linkinfo links lfc_getreplica ( string path, string guid, string se ) -> ListOf struct lfc_filereplica replicas lfc_getreplicas ( ListOfString guids, string se ) -> ListOf struct lfc_filereplicas replicas lfc_getreplicasl ( ListOfString paths, string se ) -> ListOf struct lfc_filereplicas replicas lfc_getreplicass ( ListOfString paths, ) -> ListOf struct lfc_filereplicas replicas lfc_getreplicax ( string path, string guid, string se ) -> ListOf struct lfc_filereplicax replicas lfc_lchown ( string path, uid_t new_uid, gid_t new_gid ) lfc_listreplicax ( string poolname, string server, string fs, int flags, lfc_list * listp ) -> struct lfc_filereplica replica lfc_listrepset ( string setname, int flags, lfc_list *listp ) -> struct lfc_filereplicax replica lfc_lstat ( string path ) -> struct lfc_filestat statbuf lfc_mkdir ( string path, mode_t mode ) lfc_mkdirg ( string path, string guid, mode_t mode ) lfc_modreplica ( string sfn, string setname, string poolname, string server ) lfc_modreplicax ( string sfn, string setname, string poolname, string server, string fs, char r_type ) lfc_opendir ( string path ) -> lfc_DIR dir lfc_opendirg ( string path, string guid ) -> lfc_DIR dir lfc_opendirxg ( string server, string path, string guid ) -> lfc_DIR dir lfc_ping ( string server ) -> string info lfc_readdir ( lfc_DIR dirp ) -> struct dirent dirent lfc_readdirc ( lfc_DIR dirp ) -> struct lfc_direncomm dirent lfc_readdirg ( lfc_DIR dirp ) -> struct lfc_direnstatg dirent lfc_readdirx ( lfc_DIR dirp ) -> struct lfc_direnstat dirent lfc_readdirxc ( lfc_DIR dirp ) -> struct lfc_direnstatc dirent lfc_readdirxp ( lfc_DIR dirp, string pattern, string se = None ) -> struct lfc_direnrep dirent lfc_readdirxr ( lfc_DIR dirp, string se = None ) -> struct lfc_direnrep dirent lfc_readlink ( string path ) -> string link lfc_registerfiles ( ListOf struct lfc_filereg files ) -> ListOfInt results lfc_rename ( string oldpath, string newpath ) lfc_rewinddir ( lfc_DIR dirp ) lfc_rmdir ( string path ) lfc_setacl ( string path, ListOf struct lfc_acl acls ) lfc_setatime ( string path, struct lfc_fileid file_uniqueid ) lfc_setcomment ( string path, string comment ) lfc_setfsize ( string path, struct lfc_fileid file_uniqueid, long filesize ) lfc_setfsizec ( string path, struct lfc_fileid file_uniqueid, long filesize, string csumtype, string csumvalue ) lfc_setfsizeg ( string guid, long filesize, string csumtype, string csumvalue ) lfc_setptime ( string sfn, long ptime ) lfc_setratime ( string sfn ) lfc_setrltime ( string sfn, long ltime ) lfc_setrstatus ( string sfn, char status ) lfc_setrtype ( string sfn, char type ) lfc_startsess ( string server, string comment ) lfc_starttrans ( string server, string comment ) lfc_stat ( string path ) -> struct lfc_filestat statbuf lfc_statg ( string path, string guid ) -> struct lfc_filestatg statbuf lfc_statr ( string sfn) ) -> struct lfc_filestatg statbuf lfc_symlink ( string target, string linkname ) lfc_umask ( mode_t cmask ) -> mode_t oldmask lfc_undelete ( string path ) lfc_unlink ( string path ) lfc_utime ( string path, struct utimbuf times ) lfc_entergrpmap ( gid_t gid, string groupname ) lfc_enterusrmap ( uid_t uid, string username ) lfc_getgrpbygid ( gid_t gid ) -> string group lfc_getgrpbygids ( ListOfgid_t gids ) -> ListOfString groups lfc_getgrpbynam ( string groupname ) -> gid_t gid lfc_getgrpmap ( ) -> ListOf struct lfc_groupinfo infos lfc_getidmap ( string username, ListOfString vo_roles ) -> uid_t uid, ListOf gid_t gids lfc_getusrbynam ( string username ) -> uid_t uid lfc_getusrbyuid ( uid_t uid ) -> string user lfc_getusrmap ( ) -> ListOf struct lfc_userinfo userinfo lfc_modifygrpmap ( gid_t gid, string newname ) lfc_modifyusrmap ( uid_t uid, string newname ) lfc_rmgrpmap ( gid_t gid, string groupname ) lfc_rmusrmap ( uid_t uid, string username )

STRUCTURES¶

Sometimes you need to specify a structure as an input argument (eg. struct lfc_acl, struct lfc_list, etc.). For that purpose, the module includes structure constructors, named exactly as the structure. Thus, to create struct lfc_acl or struct lfc_list, you have to do the following:

    lfcacl = lfc.lfc_acl()
    lfclist = lfc.lfc_list()

If you want to see how to use it in a real case, please have a look at examples.

ERRORS¶

As you can see, no error code is returned. When an error occurs, an exception is raised with a description of the error.

EXAMPLE¶

#!/usr/bin/python

import sys
import traceback
import lfc2 as lfc

"""
# stat an existing entry in the LFC and print the GUID
"""

name = "/grid/dteam/my.test"

try:
   stat = lfc.lfc_statg(name,"")
except Exception:
   traceback.print_exc()
   sys.exit(1)

guid = stat.guid
print "The GUID for " + name + " is " + guid

EXAMPLE¶

#!/usr/bin/python

import sys
import traceback
import lfc2 as lfc

"""
# setting and retrieving a comment on a file
"""

file = "/grid/dteam/my.test"
comment = "MyComment"

try:
   lfc.lfc_setcomment(file,comment)

   comment = lfc.lfc_getcomment(file)
   print "Read back comment " + comment
except Exception:
   traceback.print_exc()
   sys.exit(1)

EXAMPLE¶

#!/usr/bin/python

"""
# Using the lfc_readdirxr method
"""

import sys
import traceback
import lfc2 as lfc

name = "/grid/dteam/my.test"

try:
   dir = lfc.lfc_opendir(name)

   while 1:
      entry = lfc.lfc_readdirxr(dir)
      if entry == None:
         break
      print entry.d_name
      for i in range(entry.nbreplicas):
         print " ==> %s" % entry.rep[i].sfn

   lfc.lfc_closedir(dir)
except TypeError, x:
   print " ==> None"
except Exception:
   traceback.print_exc()
   sys.exit(1)

EXAMPLE¶

#!/usr/bin/python

import sys
import traceback
import lfc2 as lfc

"""
# Using the lfc_getreplica method
"""

file = "/grid/dteam/my.test"

try:
   list = lfc.lfc_getreplica(file, "", "")
except Exception:
   traceback.print_exc()
   sys.exit(1)

for i in list:
   print i.host
   print i.sfn

EXAMPLE¶

#!/usr/bin/python

import sys
import traceback
import lfc2 as lfc

"""
# Using the lfc_getacl and lfc_setacl methods to add a user ACL
"""

file = "/grid/dteam/my.test"

try:
   acls_list = lfc.lfc_getacl(file)
except Exception:
   traceback.print_exc()
   sys.exit(1)

for i in acls_list:
        print i.a_type
        print i.a_id
        print i.a_perm

# When adding a first ACL for a given user, you also need to add the mask
# When adding the second user ACL, it is not necessary anymore

acl_user = lfc.lfc_acl()
acl_mask = lfc.lfc_acl()

acl_user.a_type = lfc.CNS_ACL_USER
acl_user.a_id = 18701		# user id
acl_user.a_perm = lfc.S_IROTH | lfc.S_IXOTH

acl_mask.a_type = lfc.CNS_ACL_MASK
acl_mask.a_id = 0			# no user id specified
acl_mask.a_perm = lfc.S_IROTH | lfc.S_IXOTH

acls_list.append(acl_user)
acls_list.append(acl_mask)

try:
   lfc.lfc_setacl(file, acls_list)
except Exception:
   traceback.print_exc()
   sys.exit(1)

EXAMPLE¶

#!/usr/bin/python

import sys
import traceback
import lfc2 as lfc

"""
# Using the lfc_getacl and lfc_setacl methods to remove a user ACL
"""

file = "/grid/dteam/my.test"

try:
   acls_list = lfc.lfc_getacl(file)
except Exception:
   traceback.print_exc()
   sys.exit(1)

for i in acls_list:
        print i.a_type
        print i.a_id
        print i.a_perm

del acls_list[1]	# delete a given user ACL from the list of ACLs

try:
   lfc.lfc_setacl(file, acls_list)
except Exception:
   traceback.print_exc()
   sys.exit(1)

EXAMPLE¶

#!/usr/bin/env python
import lfc2thr as lfc
import os
from threading import Thread

class slave(Thread):

   def __init__ (self):
      Thread.__init__(self)
      
   def run(self):
        ....
        result = lfc.lfc_getreplica("", guid, "")
        ....
        return
        
if __name__ == '__main__':

    os.environ['LFC_HOST'] = 'my_lfc.cern.ch'

    #	Threaded library initialisation
    lfc.init()

    ....
    #	Start up of threads
    for i in xrange(totalNumberOfSlaves):
        slv = slave(i)
        slv.start()
        
    ....

EXAMPLE¶

#!/usr/bin/python

import sys
import traceback
import lfc2 as lfc

"""
# Using the lfc_getusrmap method
"""

try:
   list = lfc.lfc_getusrmap()
except Exception:
   traceback.print_exc()
   sys.exit(1)

for i in list:
   print i.userid + " " + i.username

EXAMPLE¶

#!/usr/bin/python

import sys
import traceback
import lfc2 as lfc

"""
# Using the lfc_getgrpmap method
"""

try:
   list = lfc.lfc_getgrpmap()
except Exception:
   traceback.print_exc()
   sys.exit(1)
    
for i in list:
   print i.gid + " " + i.groupname

EXAMPLE¶

#!/usr/bin/python

import sys
import traceback
import lfc2 as lfc

"""
# Using the lfc_getidmap method
"""

userdn = "user certificate DN"
vo_roles = ["dteam"]

try:
   uid, gids = lfc.lfc_getidmap (userdn, vo_roles)
except Exception:
   traceback.print_exc()
   sys.exit(1)

print "uid=", uid
print "gids=", gids

SEE ALSO¶

LFC C interface man pages