#
# rhevreg: register an image
#
# Copyring (C) 2011 Red Hat, Inc.
#
# requires:
#  ElementTree as built into Python 2.6.2 (xml.etree)
#

import sys
import os
import errno
import subprocess
# import exceptions
import httplib
import urlparse
import base64
import string
import json
import uuid
import time
import stat
# import xml.etree.ElementTree -- meh, code gets too verbose
# from xml.etree import ElementTree as et -- hate renaming, it's like typedef
from xml.etree import ElementTree

TAG = "rhevreg"
NFSUID = 36
NFSGID = 36
NULID = "00000000-0000-0000-0000-000000000000"

def Usage():
    print >>sys.stderr, "Usage: "+TAG+" ["+TAG+".conf]"
    sys.exit(1)

def cfg_verify(cfg, key):
    if not cfg.has_key(key):
        print >>sys.stderr, TAG+": Error in configuration, missing key:", key
        sys.exit(1)

def apipaths(connection, headers, path):

    connection.request("GET", path, '', headers)
    response = connection.getresponse()
    if response.status != 200:
        print >>sys.stderr, TAG+": API error: `GET "+path+"' status:", \
          response.status
        sys.exit(2)
    body = response.read()
    # XXX can body be None? Exception?

    # Apparently ElementTree does not throw its own exceptions, so no try:.
    etroot = ElementTree.fromstring(body)
    if etroot == None:
        print >>sys.stderr, TAG+": API error: cannot parse root for `api'"
        sys.exit(2)
    if etroot.tag != 'api':
        print >>sys.stderr, TAG+": API error: root is not `api'"
        sys.exit(2)

    #etsumtot = etroot.find("summary/storage_domains/total")
    #if etsumtot == None:
    #    print >>sys.stderr, TAG+": API error: cannot find "+\
    #      "summary/storage_domains/total"
    #    sys.exit(2)
    #etsumact = etroot.find("summary/storage_domains/active")
    #if etsumact == None:
    #    print >>sys.stderr, TAG+": API error: cannot find "+\
    #      "summary/storage_domains/active"
    #    sys.exit(2)
    #print "Storage Domains: total", etsumtot.text, "active", etsumact.text

    pathsd = None
    for et in etroot:
        if et.tag != 'link':
            continue
        if et.attrib.get('rel') != "storagedomains":
            continue
        pathsd = et.attrib.get('href')

    pathdc = None
    for et in etroot:
        if et.tag != 'link':
            continue
        if et.attrib.get('rel') != "datacenters":
            continue
        pathdc = et.attrib.get('href')

    if pathsd == None:
        print >>sys.stderr, TAG+": API error: no path for storagedomains"
        sys.exit(2)
    if pathdc == None:
        print >>sys.stderr, TAG+": API error: no path for datacenters"
        sys.exit(2)

    return (pathsd, pathdc)

def apistordom(cfg, connection, headers, pathsd):

    # XXX GET /rhevm-api/storagedomains/ crashes server, see bz#670397
    # So for now we ignore the pathsd and use a query instead.
    #connection.request("GET", pathsd, '', headers)
    connection.request("GET", \
      "/rhevm-api/storagedomains/?search=type%20%21%3D%20fcp", '', headers)

    response = connection.getresponse()
    if response.status != 200:
        print >>sys.stderr, TAG+": API error: `GET "+pathsd+"' status:", \
          response.status
        sys.exit(2)
    body = response.read()

    etroot = ElementTree.fromstring(body)
    if etroot == None:
        print >>sys.stderr, \
          TAG+": API error: cannot parse root for `storage_domains'"
        sys.exit(2)
    if etroot.tag != 'storage_domains':
        print >>sys.stderr, TAG+": API error: root is not `storage_domains'"
        sys.exit(2)

    # If we weren't lame, we'd return a class, not raw dictionary.
    # We are not json, we know the fields ahead of time. But we're lazy.
    # The C version returns a struct, naturally, so it's all good in the end.
    sd = None
    for et in etroot:
        if et.tag != 'storage_domain':
            continue
        ettype = et.find("type")
        if ettype == None:
            continue
        if ettype.text != "EXPORT":
            continue
        etstype = et.find("storage/type")
        if etstype == None:
            continue
        if etstype.text != 'NFS':
            continue

        uuidsd = et.attrib.get('id')
        if uuidsd == None:
            print >>sys.stderr, TAG+": NFS storage domain without UUID"
            continue
        etaddr = et.find("storage/address")
        if etaddr == None:
            print >>sys.stderr, TAG+": NFS storage domain without address:", \
              et.find("name").text
            continue
        etpath = et.find("storage/path")
        if etpath == None:
            print >>sys.stderr, TAG+": NFS storage domain without path:", \
              et.find("name").text
            continue

        # XXX canonicalize host in case of e.g. raw IPv4/IPv6 address.
        if etaddr.text != cfg['nfshost']:
            print "Host `"+etaddr.text+\
              "' does not match cfg `"+cfg['nfshost']+"'"
            continue
        if etpath.text != cfg['nfspath']:
            print "Path `"+etaddr.text+\
              "' does not match cfg `"+cfg['nfspath']+"'"
            continue

        sd = {}
        sd['uuid'] = uuidsd
        sd['address'] = etaddr.text
        sd['path'] = etpath.text

    if sd == None:
        print >>sys.stderr, TAG+": NFS storage domain for `"+\
          cfg['nfshost']+':'+cfg['nfspath']+"' not found"
        sys.exit(1)

    return sd

def apipoolid(cfg, connection, headers, pathsds, sd_uuid):

    connection.request("GET", pathsds, '', headers)

    response = connection.getresponse()
    if response.status != 200:
        print >>sys.stderr, TAG+": API error: `GET "+pathsds+"' status:", \
          response.status
        sys.exit(2)
    body = response.read()

    etroot = ElementTree.fromstring(body)
    if etroot == None:
        print >>sys.stderr, \
          TAG+": API error: cannot parse root for `storage_domains'"
        sys.exit(2)
    if etroot.tag != 'storage_domains':
        print >>sys.stderr, TAG+": API error: root is not `storage_domains'"
        sys.exit(2)

    for etsd in etroot:
        if etsd.tag != 'storage_domain':
            continue
        xid = etsd.attrib.get('id')
        if xid == None:
            print >>sys.stderr, TAG+": storage domain without UUID"
            continue
        if xid == sd_uuid:
            return 1

    return 0

def apipool(cfg, connection, headers, pathdc, sd_uuid):

    connection.request("GET", pathdc, '', headers)

    response = connection.getresponse()
    if response.status != 200:
        print >>sys.stderr, TAG+": API error: `GET "+pathdc+"' status:", \
          response.status
        sys.exit(2)
    body = response.read()

    etroot = ElementTree.fromstring(body)
    if etroot == None:
        print >>sys.stderr, \
          TAG+": API error: cannot parse root for `data_centers'"
        sys.exit(2)
    if etroot.tag != 'data_centers':
        print >>sys.stderr, TAG+": API error: root is not `data_centers'"
        sys.exit(2)

    for etdc in etroot:
        if etdc.tag != 'data_center':
            continue
        uuiddc = etdc.attrib.get('id')
        if uuiddc == None:
            print >>sys.stderr, TAG+": data center without UUID"
            continue

        for etlink in etdc:
            # most likely it's not even a link, but "name" or "version"
            if etlink.tag != 'link':
                continue
            rel = etlink.attrib.get('rel')
            if rel == None:
                continue
            # there's a bunch of other links like "files", "permissions"
            if rel != 'storagedomains':
                continue
            href = etlink.attrib.get('href')
            if href == None:
                print >>sys.stderr, TAG+": data canter link without href"
                continue

            if apipoolid(cfg, connection, headers, href, sd_uuid):
                # StoragePoolId is Data Center's UUID
                return uuiddc

    print >>sys.stderr, \
        TAG+": Error: pool not found for storage domain "+sd_uuid
    sys.exit(2)

def apistart(cfg):
    # Note that using a proper URL parser means that we drop query and
    # fragment from the configured URL. Fortunately, it is never a factor
    # in RHEV-M API, due to its RESTful nature.
    scheme, host, path, u_par, u_query, u_frag = urlparse.urlparse(cfg['apiurl'])
    connection = httplib.HTTPConnection(host)

    headers = {}

    authraw = cfg['apiuser'] + ':' + cfg['apipass']
    authval = 'Basic ' + string.strip(base64.encodestring(authraw))
    headers['Authorization'] = authval;

    # Step 1, fetch the API root

    # This is largely a formality, because if we know names of resources,
    # why not to fetch resources directly? But the docs imply we should
    # jump through this hoop.

    pathsd, pathdc = apipaths(connection, headers, path)

    # We should pull the API version and check that it's more than 2.3 XXX

    # Step 2, connect again, get domains

    sd = apistordom(cfg, connection, headers, pathsd)

    # Step 3, find the "storage pool ID"

    # This is crazy to be a separate step. You'd expect the storage domain
    # descriptor itself contain its pool, to be saved on Step 2. But no.

    sd['poolid'] = apipool(cfg, connection, headers, pathdc, sd['uuid'])

    connection.close()

    return sd

def spitovf(cfg, sd, img_uuid, vol_uuid, vol_size):
    domdir = cfg['nfsdir']+'/'+sd['uuid']
    tpl_uuid = uuid.uuid4()

    now = time.gmtime()

    etroot = ElementTree.Element('ovf:Envelope')
    etroot.set('xmlns:ovf', "http://schemas.dmtf.org/ovf/envelope/1/")
    etroot.set('xmlns:rasd', "http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_ResourceAllocationSettingData")
    etroot.set('xmlns:vssd', "http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_VirtualSystemSettingData")
    etroot.set('xmlns:xsi', "http://www.w3.org/2001/XMLSchema-instance")
    etroot.set('ovf:version', "0.9")

    etref = ElementTree.Element('References')

    etfile = ElementTree.Element('File')
    etfile.set('ovf:href', str(img_uuid)+'/'+str(vol_uuid))
    etfile.set('ovf:id', str(vol_uuid))
    etfile.set('ovf:size', str(vol_size))
    etfile.set('ovf:description', os.path.basename(cfg['image']))
    etref.append(etfile)

    etroot.append(etref)

    etsec = ElementTree.Element('Section')
    etsec.set('xsi:type', "ovf:NetworkSection_Type")
    ete = ElementTree.Element('Info')
    ete.text = "List of Networks"
    etsec.append(ete)
    # dummy section, even though we have Ethernet defined below
    etroot.append(etsec)

    etsec = ElementTree.Element('Section')
    etsec.set('xsi:type', "ovf:DiskSection_Type")

    etdisk = ElementTree.Element('Disk')
    etdisk.set('ovf:diskId', str(vol_uuid))
    vol_size_str = str((vol_size + (1024*1024*1024) - 1) / (1024*1024*1024))
    etdisk.set('ovf:size', vol_size_str)
    etdisk.set('ovf:actual_size', vol_size_str)
    etdisk.set('ovf:vm_snapshot_id', NULID)
    etdisk.set('ovf:fileRef', str(img_uuid)+'/'+str(vol_uuid))
    etdisk.set('ovf:format',\
        'http://www.vmware.com/technical-resources/interfaces/vmdk_access.html')
    etdisk.set('ovf:volume-format', "RAW")
    etdisk.set('ovf:volume-type', "Preallocated")
    etdisk.set('ovf:disk-interface', "VirtIO")
    etdisk.set('ovf:disk-type', "System")
    etdisk.set('ovf:boot', "true")
    etdisk.set('ovf:wipe-after-delete', "false")
    etsec.append(etdisk)

    etroot.append(etsec)

    etcon = ElementTree.Element('Content')
    etcon.set('xsi:type', "ovf:VirtualSystem_Type")
    etcon.set('ovf:id', "out")

    ete = ElementTree.Element('Name')
    ete.text = os.path.basename(cfg['image'])
    etcon.append(ete)

    ete = ElementTree.Element('TemplateId')
    ete.text = str(tpl_uuid)
    etcon.append(ete)

    # spec also has 'TemplateName'

    ete = ElementTree.Element('Description')
    ete.text = "Template by iwhd"
    etcon.append(ete)

    ete = ElementTree.Element('Domain')
    # AD domain, not in use right now
    # ete.text = 
    etcon.append(ete)

    ete = ElementTree.Element('CreationDate')
    ete.text = time.strftime("%Y/%m/%d %H:%M:%S", now)
    etcon.append(ete)

    ete = ElementTree.Element('TimeZone')
    # ete.text = 
    etcon.append(ete)

    ete = ElementTree.Element('IsAutoSuspend')
    ete.text = "false"
    etcon.append(ete)

    ete = ElementTree.Element('VmType')
    ete.text = "1"
    etcon.append(ete)

    ete = ElementTree.Element('default_display_type')
    # vnc = 0, gxl = 1
    ete.text = "0"
    etcon.append(ete)

    ete = ElementTree.Element('default_boot_sequence')
    # C=0,   DC=1,  N=2, CDN=3, CND=4, DCN=5, DNC=6, NCD=7,
    # NDC=8, CD=9, D=10, CN=11, DN=12, NC=13, ND=14
    # (C - HardDisk, D - CDROM, N - Network)
    ete.text = "1"
    etcon.append(ete)

    etsec = ElementTree.Element('Section')
    etsec.set('xsi:type', "ovf:OperatingSystemSection_Type")
    etsec.set('ovf:id', str(tpl_uuid))
    etsec.set('ovf:required', "false")

    ete = ElementTree.Element('Info')
    ete.text = "Guest OS"
    etsec.append(ete)

    ete = ElementTree.Element('Description')
    # This is rigid, must be "Other", "OtherLinux", "RHEL6", or such.
    ete.text = "OtherLinux"
    etsec.append(ete)

    etcon.append(etsec)

    etsec = ElementTree.Element('Section')
    etsec.set('xsi:type', "ovf:VirtualHardwareSection_Type")

    ete = ElementTree.Element('Info')
    ete.text = "1 CPU, 512 Memory"
    etsec.append(ete)

    etsys = ElementTree.Element('System')
    # This is probably wrong, needs actual type.
    ete = ElementTree.Element('vssd:VirtualSystemType')
    ete.text = "RHEVM 4.6.0.163"
    etsys.append(ete)
    etsec.append(etsys)

    etitem = ElementTree.Element('Item')

    ete = ElementTree.Element('rasd:Caption')
    ete.text = "1 virtual CPU"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:Description')
    ete.text = "Number of virtual CPU"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:InstanceId')
    ete.text = "1"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:ResourceType')
    ete.text = "3"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:num_of_sockets')
    ete.text = "1"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:cpu_per_socket')
    ete.text = "1"
    etitem.append(ete)

    etsec.append(etitem)

    etitem = ElementTree.Element('Item')

    ete = ElementTree.Element('rasd:Caption')
    ete.text = "512 MB of memory"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:Description')
    ete.text = "Memory Size"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:InstanceId')
    ete.text = "2"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:ResourceType')
    ete.text = "4"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:AllocationUnits')
    ete.text = "MegaBytes"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:VirtualQuantity')
    ete.text = "512"
    etitem.append(ete)

    etsec.append(etitem)

    etitem = ElementTree.Element('Item')

    ete = ElementTree.Element('rasd:Caption')
    ete.text = "Drive 1"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:InstanceId')
    ete.text = str(vol_uuid)
    etitem.append(ete)

    ete = ElementTree.Element('rasd:ResourceType')
    ete.text = "17"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:HostResource')
    ete.text = str(img_uuid)+'/'+str(vol_uuid)
    etitem.append(ete)

    ete = ElementTree.Element('rasd:Parent')
    ete.text = NULID
    etitem.append(ete)

    ete = ElementTree.Element('rasd:Template')
    ete.text = NULID
    etitem.append(ete)

    ete = ElementTree.Element('rasd:ApplicationList')
    # List of installed applications, separated by comma
    etitem.append(ete)

    # This corresponds to ID of volgroup in host where snapshot was taken.
    # Obviously we have nothing like it.
    ete = ElementTree.Element('rasd:StorageId')
    # "Storage Domain Id"
    ete.text = NULID
    etitem.append(ete)

    ete = ElementTree.Element('rasd:StoragePoolId')
    ete.text = sd['poolid']
    etitem.append(ete)

    ete = ElementTree.Element('rasd:CreationDate')
    ete.text = time.strftime("%Y/%m/%d %H:%M:%S", now)
    etitem.append(ete)

    ete = ElementTree.Element('rasd:LastModified')
    ete.text = time.strftime("%Y/%m/%d %H:%M:%S", now)
    etitem.append(ete)

    etsec.append(etitem)

    etitem = ElementTree.Element('Item')

    ete = ElementTree.Element('rasd:Caption')
    ete.text = "Ethernet 0 rhevm"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:InstanceId')
    ete.text = "3"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:ResourceType')
    ete.text = "10"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:ResourceSubType')
    # e1000 = 2, pv = 3
    ete.text = "3"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:Connection')
    ete.text = "rhevm"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:Name')
    ete.text = "eth0"
    etitem.append(ete)

    # also allowed is "MACAddress"

    ete = ElementTree.Element('rasd:speed')
    ete.text = "1000"
    etitem.append(ete)

    etsec.append(etitem)

    etitem = ElementTree.Element('Item')

    ete = ElementTree.Element('rasd:Caption')
    ete.text = "Graphics"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:InstanceId')
    # doc says "6", reality is "5"
    ete.text = "5"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:ResourceType')
    ete.text = "20"
    etitem.append(ete)

    ete = ElementTree.Element('rasd:VirtualQuantity')
    ete.text = "1"
    etitem.append(ete)

    etsec.append(etitem)

    etcon.append(etsec)

    etroot.append(etcon)

    tmpovfdir = domdir+"/iwhd."+str(tpl_uuid)
    try:
        os.mkdir(tmpovfdir)
    except OSError, e:
        if e.errno != errno.EEXIST:
            print >>sys.stderr, TAG+": Cannot make directory :", e
            sys.exit(1)
    et = ElementTree.ElementTree(etroot)
    tmpovf = tmpovfdir+"/"+str(tpl_uuid)+".ovf"
    et.write(tmpovf, encoding="UTF-8")

    tmpimgdir = domdir+"/iwhd."+str(img_uuid)
    imgdir = domdir+"/images/"+str(img_uuid)
    os.rename(tmpimgdir, imgdir)

    ovfdir = domdir+"/master/vms/"+str(tpl_uuid)
    os.rename(tmpovfdir, ovfdir)

    return tpl_uuid

def copyimage(cfg, sd):
    ## We do not want to run as root, and we do not want to garbage-collect
    ## old mounts, so we expect the user to mount everything ahead of time.
    ##
    #if os.geteuid() != 0:
    #    print >>sys.stderr, TAG+": Have to run as root"
    #    sys.exit(1)
    #
    #nfsdir = cfg['nfsdir']
    #try:
    #    os.mkdir(nfsdir)
    #except OSError, e:
    #    if e.errno != errno.EEXIST:
    #        print >>sys.stderr, TAG+": Cannot make directory :", e
    #        sys.exit(1)
    #
    #export = cfg['nfshost']+":"+cfg['nfspath']
    #rc = subprocess.call(["/bin/mount", "-t", "nfs", "-o", "nolock", export, nfsdir])
    #if rc != 0:
    #    print >>sys.stderr, TAG+": cannot mount "+export+" on "+nfsdir+" :", rc
    #    sys.exit(1)

    if os.geteuid() == 0:
        #print "We're root, changing user and group to 36"
        # N.B. -1 is not a valid input in Python.
        os.setregid(NFSGID, NFSGID);
        os.setreuid(NFSUID, NFSUID);
    else:
        if os.geteuid() != NFSUID or os.getegid() != NFSGID:
            print >>sys.stderr, TAG+": Have to run with user and group 36"
            sys.exit(1)

    domdir = cfg['nfsdir']+'/'+sd['uuid']
    if not os.path.isdir(domdir):
        print >>sys.stderr, TAG+": path `"+domdir+"' is not a directory"
        sys.exit(1)

    # Note that uuid1 called twice quickly returns the same UUID, so uuid4.
    # XXX Check what the first uuid call does (does it run anything?)
    vol_uuid = uuid.uuid4()
    img_uuid = uuid.uuid4()

    # copy stuff
    # XXX Do something about garbage-collecting iwhd.* directories

    tmpimgdir = domdir+"/iwhd."+str(img_uuid)
    try:
        os.mkdir(tmpimgdir)
    except OSError, e:
        # errno.EEXIST is an error here too (loss of uniqueness)
        print >>sys.stderr, TAG+": Cannot make directory :", e
        sys.exit(1)

    now = int(time.time())

    imgsrc = cfg['image']
    imgdst = tmpimgdir+'/'+str(vol_uuid)
    rc = subprocess.call(["/bin/cp", imgsrc, imgdst])
    if rc != 0:
        print >>sys.stderr, TAG+": cannot copy "+imgsrc+" to "+imgdst+" :", rc
        sys.exit(1)

    statb = os.stat(imgdst)
    vol_size = statb[stat.ST_SIZE]

    imgmeta = imgdst+".meta"
    try:
        fp = open(imgmeta, "w")
    except IOError, e:
        print >>sys.stderr, TAG+": Error opening OVF:", e
        sys.exit(1)
    print >>fp, "DOMAIN="+sd['uuid']
    # saved template has VOLTYPE=SHARED
    print >>fp, "VOLTYPE=LEAF"
    print >>fp, "CTIME="+str(now)
    # saved template has FORMAT=COW
    print >>fp, "FORMAT=RAW"
    print >>fp, "IMAGE="+str(img_uuid)
    print >>fp, "DISKTYPE=1"
    print >>fp, "PUUID="+NULID
    print >>fp, "LEGALITY=LEGAL"
    print >>fp, "MTIME="+str(now)
    print >>fp, "POOL_UUID="+sd['poolid']
    # assuming 1KB alignment, so 512 is no problem
    print >>fp, "SIZE="+str(vol_size/512)
    print >>fp, "TYPE=SPARSE"
    print >>fp, "DESCRIPTION=Uploaded by iwhd+rhevreg"
    print >>fp, "EOF"
    fp.close()

    return spitovf(cfg, sd, img_uuid, vol_uuid, vol_size)

def main():

    argc = len(sys.argv)
    if argc == 1:
        cfgname = TAG+".conf"
    elif argc == 2:
        cfgname = sys.argv[1]
        if len(cfgname) == 0 or cfgname[0] == '-':
            Usage()
    else:
        Usage()

    try:
        fp = open(cfgname, 'r')
    except IOError, e:
        # printing e outpus the filename too, so no explicit cfgname in printout
        print >>sys.stderr, TAG+": Error opening configuration:", e
        sys.exit(1)

    try:
        cfg = json.load(fp)
    except ValueError, e:
        print >>sys.stderr, TAG+": Error parsing configuration:", e
        sys.exit(1)

    fp.close()

    # Verify the class members here, so that we do not traceback unexpectedly.
    #
    # image: local filename with disk image
    cfg_verify(cfg, 'image')
    if not os.path.exists(cfg['image']):
        print >>sys.stderr, TAG+": Image `"+cfg['image']+"' does not exist"
        sys.exit(1)
    # apiurl: the so-called "base", usually "rhev-api"
    cfg_verify(cfg, 'apiurl')
    # apiuser: username@AD.domain
    # We do not enforce with '@' syntax in case someone comes up with RHEV-M
    # that takes local authentication of some other trick.
    cfg_verify(cfg, 'apiuser')
    # apipass: password for apiuser
    cfg_verify(cfg, 'apipass')
    # nfshost: NFS server name
    # nfspath: export path
    # All RHEV-M servers have several storage domains, so we use this to
    # select one. Also, we verify if 'nfsdir' points where it should.
    cfg_verify(cfg, 'nfshost')
    cfg_verify(cfg, 'nfspath')
    # nfsdir: A directory where sysadmin or boot scripts or autofs mounted
    # the same area that RHEV-M considers an export domain (/mnt/vdsm/rhevm23).
    # N.B. If iwhd is running on the NFS server itself, nfsdir can be the
    # exported directory itself (like /home/vdsm/rhevm23). We verify that
    # the directory contains an expected structure, so attach it to RHEV-M
    # before trying to register any images.
    cfg_verify(cfg, 'nfsdir')
    d = cfg['nfsdir']
    if len(d) == 0:
        print >>sys.stderr, TAG+": Error in configuration, `nfsdir' is empty"
        sys.exit(1)
    if not os.path.isabs(d):
        print >>sys.stderr, \
          TAG+": Error in configuration, `nfsdir' is relative:", d
        sys.exit(1)

    sd = apistart(cfg)

    tpl_uuid = copyimage(cfg, sd)

    print "IMAGE", str(tpl_uuid)

# http://utcc.utoronto.ca/~cks/space/blog/python/ImportableMain
# TODO: replace sys.exit with exceptions (check hailcampack.py ConfigError)
if __name__ == "__main__":
    main()