NAME¶

dpm - Python interface to the DPM

SYNOPSIS¶

import dpm

DESCRIPTION¶

The dpm module permits you to access the DPM client interface from python programs. The dpm module is a swig wrapping of the standard C interface. For detailed descriptions of each function see the individual man page of each function. There follows a series of examples of how to use selected functions and how to retrieve the information returned by them: Examples are listing the replicas of a given entry, reading the content of a directory, getting and setting ACLs. etc.

EXAMPLE¶

#!/usr/bin/python

"""
# Using the dpns_readdirxr method
"""

import sys
import dpm

name = "/dpm/cern.ch/home/dteam/";

dir = dpm.dpns_opendirg(name,"")
if (dir == None) or (dir == 0):
        err_num = dpm.cvar.serrno
        err_string = dpm.sstrerror(err_num)
        print "Error while looking for " + name + ": Error " + str(err_num) \
			+ " (" + err_string + ")"
        sys.exit(1)

while 1:
        read_pt = dpm.dpns_readdirxr(dir,"")
        if (read_pt == None) or (read_pt == 0):
                break
        entry, list = read_pt
        print entry.d_name
        try:
                for i in range(len(list)):
                        print " ==> %s" % list[i].sfn
        except TypeError, x:
                print " ==> None"

dpm.dpns_closedir(dir)

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpns_getlinks method
"""

result, list = dpm.dpns_getlinks("/dpm/cern.ch/home/dteam/file.test", "")
print result
print len(list)
if (result == 0):
	for i in list:
		print i.path

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpns_getreplica method
"""

result, list = dpm.dpns_getreplica("/dpm/cern.ch/home/dteam/file.test", "", "")
print result
print len(list)
if (result == 0):
	for i in list:
		print i.host
		print i.sfn

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpns_getacl and dpns_setacl methods to add a user ACL
"""

nentries, acls_list = dpm.dpns_getacl("/dpm/cern.ch/home/dteam/file.test", \
					dpm.CA_MAXACLENTRIES)

print nentries
print len(acls_list)

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 = dpm.dpns_acl()
acl_mask = dpm.dpns_acl()

acl_user.a_type=2		# 2 corresponds to CNS_ACL_USER
acl_user.a_id=18701		# user id
acl_user.a_perm=5

acl_mask.a_type=5		# 5 corresponds to CNS_ACL_MASK
acl_mask.a_id=0			# no user id specified
acl_mask.a_perm=5

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

res = dpm.dpns_setacl("/dpm/cern.ch/home/dteam/file.test", acls_list)

if res == 0:
        print "OK"
else:
        err_num = dpm.cvar.serrno
        err_string = dpm.sstrerror(err_num)
        print "There was an error : Error " + str(err_num) + " (" + err_string + ")"
        sys.exit(1)

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpns_getacl and dpns_setacl methods to remove a user ACL
"""

nentries, acls_list = dpm.dpns_getacl("/dpm/cern.ch/home/dteam/file.test", \
						dpm.CA_MAXACLENTRIES)

# Note : you cannot remove the owner ACL (i.e. for CNS_ACL_USER_OBJ type) if
# ====== ACLs for other users exist. If all the other user ACLs are deleted,
# ====== the owner ACL is automatically removed.

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

res = dpm.dpns_setacl("/dpm/cern.ch/home/dteam/file.test", acls_list)

if res == 0:
        print "OK"
else:
        err_num = dpm.cvar.serrno
        err_string = dpm.sstrerror(err_num)
        print "There was an error : Error " + str(err_num) + " (" + err_string + ")"
        sys.exit(1)

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpns_getusrmap method
"""

result, list = dpm.dpns_getusrmap()
print result
print len(list)
if (result == 0):
	for i in list:
		print i.userid + " " + i.username

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpns_getgrpmap method
"""

result, list = dpm.dpns_getgrpmap()
print result
print len(list)
if (result == 0):
	for i in list:
		print i.gid + " " + i.groupname

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_addfs method
"""

result = dpm.dpm_addfs("mypool", "mydiskserver.domain.com", "/mountpoint", \
			dpm.FS_READONLY)
print result

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_modifyfs method
"""

result = dpm.dpm_modifyfs("mydiskserver.domain.com", "/mountpoint", \
			dpm.FS_READONLY)
print result

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_rmfs method
"""

result = dpm.dpm_rmfs("mypool", "mydiskserver.domain.com", "/mountpoint")
print result

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_addpool method
"""

dpmpool = dpm.dpm_pool()
dpmpool.poolname = "mypool"
dpmpool.defsize = 209715200
dpmpool.def_lifetime = 604800
dpmpool.defpintime = 604800
dpmpool.max_lifetime = 604800
dpmpool.max_pintime = 604800
dpmpool.nbgids = 1
dpmpool.gids = [0]
dpmpool.ret_policy = 'R'
dpmpool.s_type = 'D'

result = dpm.dpm_addpool(dpmpool)
print result

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_modifypool method
"""

dpmpool = dpm.dpm_pool()
dpmpool.poolname = "mypool"
dpmpool.defsize = 209715200
dpmpool.def_lifetime = 604800
dpmpool.defpintime = 604800
dpmpool.max_lifetime = 604800
dpmpool.max_pintime = 604800
dpmpool.nbgids = 1
dpmpool.gids = [0]
dpmpool.ret_policy = 'R'
dpmpool.s_type = 'D'

result = dpm.dpm_modifypool(dpmpool)
print result

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_rmpool method
"""

result = dpm.dpm_rmpool("mypool")
print result

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_getpoolfs method
"""

result,list = dpm.dpm_getpoolfs("mypool")
print result
print len(list)
if (result == 0):
	for i in list:
		print "POOL " + i.poolname + " SERVER " + i.server + " FS " + i.fs \
			+ " CAPACITY " + i.capacity + " FREE " + i.free

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_getpools method
"""

result,list = dpm.dpm_getpools()
print result
print len(list)
if (result == 0):
	for i in list:
		print "POOL " + i.poolname + " CAPACITY " + i.capacity + " FREE " + i.free

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_getprotocols method
"""

result,list = dpm.dpm_getprotocols()
print result
print len(list)
if (result == 0):
	for i in list:
		print i

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_getspacemd method
"""

result, list = dpm.dpm_getspacemd(["myspacetoken"])
print result
print len(list)
if (result == 0):
	for i in list:
		print "TYPE " + i.s_type + " SPACETOKEN " i.s_token + " USERTOKEN " \
			+ i.u_token + " TOTAL " + i.t_space + " GUARANTUEED " + i.g_space \
			+ " UNUSED " + i.u_space + " POOL " + i.poolname

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_getspacetoken method
"""

result, list = dpm.dpm_getspacetoken("myspacetokendesc")
print result
print len(list)
if (result == 0):
	for i in list:
		print i

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_reservespace method
"""

result,actual_s_type,actual_t_space,actual_g_space,actual_lifetime,s_token = \
		dpm.dpm_reservespace('D', "myspacetokendesc", 'R', 'O', 209715200, \
		209715200, 2592000, 0, "mypoolname")
print result
if (result == 0):
	print "TYPE " + actual_s_type + " TOTAL " + actual_t_space + " GUARANTEED " \
		+ actual_g_space + " LIFETIME " + actual_lifetime + " TOKEN " + s_token

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_updatespace method
"""

result,actual_t_space,actual_g_space,actual_lifetime = \
		dpm.dpm_updatespace("myspacetoken", 209715200, 209715200, 2592000)
print result
if (result == 0):
	print " TOTAL " + actual_t_space + " GUARANTEED " + actual_g_space \
		+ " LIFETIME " + actual_lifetime

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_releasespace method
"""

result = dpm.dpm_releasespace("myspacetoken", 0)
print result

EXAMPLE¶

#!/usr/bin/python

import dpm

"""
# Using the dpm_ping method
"""

result,info = dpm.dpm_ping("mydpmserver.domain.com")
print result
if (result == 0):
	print info

KNOWN BUGS¶

The current interface to the dpns_getcwd(3), dpns_readlink(3), dpns_seterrbuf(3) requires the passing of str object which is modified to contain the result (in a similar way to the C functions, which accept a buffer). However this breaks the immutability of python str. This will be changed in the future.

SEE ALSO¶

DPM C interface man pages