Python interface to the dpm
import dpm
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.
#!/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)
#!/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
#!/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
#!/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)
#!/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)
#!/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
#!/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
#!/usr/bin/python
import dpm
"""
# Using the dpm_addfs method
"""
result = dpm.dpm_addfs("mypool", "mydiskserver.domain.com", "/mountpoint", \
dpm.FS_READONLY)
print result
#!/usr/bin/python
import dpm
"""
# Using the dpm_modifyfs method
"""
result = dpm.dpm_modifyfs("mydiskserver.domain.com", "/mountpoint", \
dpm.FS_READONLY)
print result
#!/usr/bin/python
import dpm
"""
# Using the dpm_rmfs method
"""
result = dpm.dpm_rmfs("mypool", "mydiskserver.domain.com", "/mountpoint")
print result
#!/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
#!/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
#!/usr/bin/python
import dpm
"""
# Using the dpm_rmpool method
"""
result = dpm.dpm_rmpool("mypool")
print result
#!/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
#!/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
#!/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
#!/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
#!/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
#!/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
#!/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
#!/usr/bin/python
import dpm
"""
# Using the dpm_releasespace method
"""
result = dpm.dpm_releasespace("myspacetoken", 0)
print result
#!/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
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.
DPM C interface man pages