Fully switch over to Python 3

[invirt/packages/invirt-images.git] / invirt-images

diff --git a/invirt-images b/invirt-images
index e6f987d..eeda870 100755 (executable)
--- a/invirt-images
+++ b/invirt-images
@@ -1,158 +1,90 @@
-#!/usr/bin/python
+#!/usr/bin/env python3

 
 

-from invirt import database

 import os
 import os

-import sys

 import subprocess
 import random
 import string
 import tempfile
 import subprocess
 import random
 import string
 import tempfile

-import urllib
+import urllib.request

 import math
 import math

-import optparse as op
-
-class InvirtImageException(Exception):
-    pass
+import optparse

 
 

-# verbosity = 0 means no output from the actual commands
-# verbosity = 1 means only errors from the actual commands
-# verbosity = 2 means all output from the actual commands
-verbosity = 0
+from invirt import database

 
 

-def getOutput():
-    global verbosity
-    return {
-        'stdout': subprocess.PIPE if verbosity < 2 else None,
-        'stderr': subprocess.PIPE if verbosity < 1 else None
-        }

 
 def lvcreate(name, size):
 
 def lvcreate(name, size):

-    lvc = subprocess.Popen(['lvcreate', '-L', size, '-n', name, 'xenvg'],
-                           stderr=subprocess.PIPE,
-                           stdout=getOutput()['stdout'])
-    if not lvc.wait():
-        return 0
-    stderr = lvc.stderr.read()
-    if 'already exists in volume group' in stderr:
-        return 5
-    else:
-        if verbosity > 0:
-            print stderr
-        return 6
+    subprocess.run(['lvcreate', '-L', size, '-n', name, 'xenvg'],
+                   check_output=True, encoding='utf-8', check=True)

 
 def lvrename(dest, src):
 
 def lvrename(dest, src):

-    lvr = subprocess.Popen(['lvchange', '-an', "xenvg/%s" % (src,)],
-                           stderr=subprocess.PIPE,
-                           stdout=getOutput()['stdout'])
-    ret = lvr.wait()
-
-    if ret:
-       if verbosity > 0:
-           print lvr.stderr.read()
-       return ret
-
-    lvr = subprocess.Popen(['lvrename', "xenvg/%s" % (src,), "xenvg/%s" % (dest,)],
-                           stderr=subprocess.PIPE,
-                           stdout=getOutput()['stdout'])
-    ret = lvr.wait()
+    subprocess.run(['lvchange', '-an', f'xenvg/{src}'],
+                   check_output=True, encoding='utf-8', check=True)

 
 

-    if ret:
-        stderr = lvr.stderr.read()
-        if not ('not found in volume group' in stderr):
-            if verbosity > 0:
-                print stderr
-            return ret
-
-    subprocess.Popen(['lvchange', '-ay', "xenvg/%s" % (dest,)],
-                     stderr=subprocess.PIPE,
-                     stdout=getOutput()['stdout'])
-    ret = lvr.wait()
-
-    if ret:
-        if verbosity > 0:
-           print lvr.stderr.read()
-
-    return ret
+    subprocess.run(['lvrename', f'xenvg/{src}', f'xenvg/{dest}'],
+                   check_output=True, encoding='utf-8', check=True)

 
 

+    subprocess.run(['lvchange', '-ay', f'xenvg/{dest}'],
+                   check_output=True, encoding='utf-8', check=True)

 
 def lv_random(func, pattern, *args):
     """
 
 def lv_random(func, pattern, *args):
     """

-    Run some LVM-related command, optionally with a random string in
-    the LV name.
-    
+    Run some LVM-related command with a random string in the LV name.
+

     func takes an LV name plus whatever's in *args and returns the
     return code of some LVM command, such as lvcreate or lvrename
     func takes an LV name plus whatever's in *args and returns the
     return code of some LVM command, such as lvcreate or lvrename

-    
-    pattern can contain at most one '%s' pattern, which will be
-    replaced by a 6-character random string.
-    
-    If pattern contains a '%s', the script will attempt to re-run
-    itself if the error code indicates that the destination already
-    exists
+
+    pattern must contain one '{}' pattern, which will be replaced
+    by a 6-character random string.
+
+    the script will attempt to re-run itself if the error code
+    indicates that the destination already exists

     """
     """

+

     # Keep trying until it works
     while True:
     # Keep trying until it works
     while True:

-        rand_string = ''.join(random.choice(string.ascii_letters) \
-                                  for i in xrange(6))
-        if '%s' in pattern:
-            name = pattern % rand_string
-        else:
-            name = pattern
-        ret = func(name, *args)
-        if ret == 0:
-            return name
-        # 5 is the return code if the destination already exists
-        elif '%s' not in pattern or ret != 5:
-            raise InvirtImageException, 'E: Error running %s with args %s' % (func.__name__, args)
+        letters = (random.choice(string.ascii_letters) for _ in range(6))
+        rand_string = ''.join(letters)

 
 

-def lvcreate_random(pattern, size):
-    """
-    Creates an LV, optionally with a random string in the name.
-    
-    Call with a string formatting pattern with a single '%s' to use as
-    a pattern for the name of the new LV.
-    """
-    return lv_random(lvcreate, pattern, size)
+        name = pattern.format(rand_string)

 
 

-def lvrename_random(src, pattern):
-    """
-    Rename an LV to a new name with a random string incorporated.
-    
-    Call with a string formatting pattern with a single '%s' to use as
-    a pattern for the name of the new LV
-    """
-    return lv_random(lvrename, pattern, src)
+        try:
+            func(name, *args)
+        except subprocess.CalledProcessError as e:
+            # 5 is the return code if the destination already exists
+            if e.returncode != 5:
+                raise
+        else:
+            return name

 
 def fetch_image(cdrom):
     """
     Download a cdrom from a URI, shelling out to rsync if appropriate
     and otherwise trying to use urllib
     """
 
 def fetch_image(cdrom):
     """
     Download a cdrom from a URI, shelling out to rsync if appropriate
     and otherwise trying to use urllib
     """

+

     full_uri = os.path.join(cdrom.mirror.uri_prefix, cdrom.uri_suffix)
     temp_file = tempfile.mkstemp()[1]
     full_uri = os.path.join(cdrom.mirror.uri_prefix, cdrom.uri_suffix)
     temp_file = tempfile.mkstemp()[1]

-    if verbosity > 0:
-        print >>sys.stderr, "Fetching image %s from %s to %s" % (cdrom.cdrom_id, full_uri, temp_file)
+    print(f'Fetching image {cdrom.cdrom_id} from {full_uri} to {temp_file}')

     try:
         if full_uri.startswith('rsync://'):
     try:
         if full_uri.startswith('rsync://'):

-            if subprocess.call(['rsync', '--no-motd', '-tLP', full_uri, temp_file],
-                               **getOutput()):
-                raise InvirtImageException, "E: Unable to download '%s'" % full_uri
+            subprocess.run(['rsync', '--no-motd', '-tLP', full_uri, temp_file],
+                           check_output=True, encoding='utf-8', check=True)

         else:
             # I'm not going to look for errors here, because I bet it'll
             # throw its own exceptions
         else:
             # I'm not going to look for errors here, because I bet it'll
             # throw its own exceptions

-            urllib.urlretrieve(full_uri, temp_file)
+            urllib.request.urlretrieve(full_uri, temp_file)

         return temp_file
     except:
         return temp_file
     except:

-        os.unlink(temp_file)
+        os.remove(temp_file)

         raise
 
 def copy_file(src, dest):
     """
     Copy a file from one location to another using dd
     """
         raise
 
 def copy_file(src, dest):
     """
     Copy a file from one location to another using dd
     """

-    if subprocess.call(['dd', 'if=%s' % src, 'of=%s' % dest, 'bs=1M'],
-                       **getOutput()):
-        raise InvirtImageException, 'E: Unable to transfer %s into %s' % (src, dest)
+
+    subprocess.run(['dd', f'if={src}', f'of={dest}', 'bs=1M'],
+                   check_output=True, encoding='utf-8', check=True)

 
 def load_image(cdrom):
     """
 
 def load_image(cdrom):
     """

@@ -160,56 +92,49 @@ def load_image(cdrom):
     transferring it into an LV, moving the old LV out of the way and
     the new LV into place
     """
     transferring it into an LV, moving the old LV out of the way and
     the new LV into place
     """

+

     if cdrom.mirror_id is None:
         return
     if cdrom.mirror_id is None:
         return

-    try:
-        temp_file = fetch_image(cdrom)
-    except InvirtImageException, e:
-        print >>sys.stderr, 'ERROR: %s.  Skipping.' % e
-        return
+
+    temp_file = fetch_image(cdrom)
+
+    st_size = os.stat(temp_file).st_size
+
+    assert st_size > 0, 'CD-ROM image size is 0'
+
+    megabytes = math.ceil((float(st_size) / (1024 * 1024)))
+    cdrom_size = f'{megabytes}M'

 
     try:
 
     try:

-        st_size = os.stat(temp_file).st_size
-        if not st_size:
-            print >>sys.stderr, "Failed to fetch %s" % cdrom.cdrom_id
-            return
-        cdrom_size = '%sM' % math.ceil((float(st_size) / (1024 * 1024)))
-        new_lv = lvcreate_random('image-new_%s_%%s' % cdrom.cdrom_id, cdrom_size)
-        copy_file(temp_file, '/dev/xenvg/%s' % new_lv)
-        lvrename_random('image_%s' % cdrom.cdrom_id, 'image-old_%s_%%s' % cdrom.cdrom_id)
-        lvrename_random(new_lv, 'image_%s' % cdrom.cdrom_id)
+        new_lv = lv_random(lvcreate, f'image-new_{cdrom.cdrom_id}' + '_{}', cdrom_size)
+        copy_file(temp_file, f'/dev/xenvg/{new_lv}')
+        lv_random(lvrename, f'image-old_{cdrom.cdrom_id}' + '_{}', 'image_{cdrom.cdrom_id}')
+        lv_random(lvrename, f'image_{cdrom.cdrom_id}', new_lv)

         reap_images()
     finally:
         reap_images()
     finally:

-        os.unlink(temp_file)
+        os.remove(temp_file)

 
 def reap_images():
     """
     Remove stale cdrom images that are no longer in use
 
 def reap_images():
     """
     Remove stale cdrom images that are no longer in use

-    
+

     load_image doesn't attempt to remove the old image because it
     might still be in use. reap_images attempts to delete any LVs
     starting with 'image-old_', but ignores errors, in case they're
     still being used.
     """
     load_image doesn't attempt to remove the old image because it
     might still be in use. reap_images attempts to delete any LVs
     starting with 'image-old_', but ignores errors, in case they're
     still being used.
     """

-    lvm_list = subprocess.Popen(['lvs', '-o', 'lv_name', '--noheadings'],
-                               stdout=subprocess.PIPE,
-                               stdin=subprocess.PIPE)
-    lvm_list.wait()
-    
-    for lv in map(str.strip, lvm_list.stdout.read().splitlines()):
+
+    lvm_list = subprocess.run(['lvs', '-o', 'lv_name', '--noheadings'],
+                              check_output=True, encoding='utf-8', check=True)
+
+    for lv in (s.strip() for s in lvm_list.stdout.readlines()):

         if lv.startswith('image-old_'):
         if lv.startswith('image-old_'):

-            subprocess.call(['lvchange', '-a', 'n', '/dev/xenvg/%s' % lv],
-                            **getOutput())
-            subprocess.call(['lvchange', '-a', 'n', '/dev/xenvg/%s' % lv],
-                            **getOutput())
-            subprocess.call(['lvchange', '-a', 'ey', '/dev/xenvg/%s' % lv],
-                            **getOutput())
-            subprocess.call(['lvremove', '--force', '/dev/xenvg/%s' % lv],
-                            **getOutput())
+            subprocess.run(['lvchange', '-a', 'n', f'/dev/xenvg/{lv}'])
+            subprocess.run(['lvchange', '-a', 'n', f'/dev/xenvg/{lv}'])
+            subprocess.run(['lvchange', '-a', 'ey', f'/dev/xenvg/{lv}'])
+            subprocess.run(['lvremove', '--force', f'/dev/xenvg/{lv}'])

 
 def main():
 
 def main():

-    global verbosity
-    

     database.connect()
     database.session.begin()
 
     database.connect()
     database.session.begin()
 

@@ -218,23 +143,23 @@ def main():
 
        %prog [options] --update [short_name1 [short_name2 ...]]
        %prog [options] --reap"""
 
        %prog [options] --update [short_name1 [short_name2 ...]]
        %prog [options] --reap"""

-    
-    parser = op.OptionParser(usage=usage)
+
+    parser = optparse.OptionParser(usage=usage)

     parser.set_defaults(verbosity=0,
                         item='cdrom')
     parser.set_defaults(verbosity=0,
                         item='cdrom')

-    
+

     parser.add_option('-a', '--add', action='store_const',
                       dest='action', const='add',
                       help='Add a new item to the database')
     parser.add_option('-a', '--add', action='store_const',
                       dest='action', const='add',
                       help='Add a new item to the database')

-    
+

     parser.add_option('-u', '--update', action='store_const',
                       dest='action', const='update',
                       help='Update all cdrom images in the database with the latest version')
     parser.add_option('-r', '--reap', action='store_const',
                       dest='action', const='reap',
                       help='Reap stale cdrom images that are no longer in use')
     parser.add_option('-u', '--update', action='store_const',
                       dest='action', const='update',
                       help='Update all cdrom images in the database with the latest version')
     parser.add_option('-r', '--reap', action='store_const',
                       dest='action', const='reap',
                       help='Reap stale cdrom images that are no longer in use')

-    
-    a_group = op.OptionGroup(parser, 'Adding new items')
+
+    a_group = optparse.OptionGroup(parser, 'Adding new items')

     a_group.add_option('-c', '--cdrom', action='store_const',
                        dest='item', const='cdrom',
                        help='Add a new cdrom to the database')
     a_group.add_option('-c', '--cdrom', action='store_const',
                        dest='item', const='cdrom',
                        help='Add a new cdrom to the database')

@@ -242,8 +167,8 @@ def main():
                        dest='item', const='mirror',
                        help='Add a new mirror to the database')
     parser.add_option_group(a_group)
                        dest='item', const='mirror',
                        help='Add a new mirror to the database')
     parser.add_option_group(a_group)

-    
-    v_group = op.OptionGroup(parser, "Verbosity levels")
+
+    v_group = optparse.OptionGroup(parser, "Verbosity levels")

     v_group.add_option("-q", "--quiet", action='store_const',
                        dest='verbosity', const=0,
                        help='Show no output from commands this script runs (default)')
     v_group.add_option("-q", "--quiet", action='store_const',
                        dest='verbosity', const=0,
                        help='Show no output from commands this script runs (default)')

@@ -254,24 +179,23 @@ def main():
                        dest='verbosity', const=2,
                        help='Show all output from commands this script runs')
     parser.add_option_group(v_group)
                        dest='verbosity', const=2,
                        help='Show all output from commands this script runs')
     parser.add_option_group(v_group)

-    
+

     (options, args) = parser.parse_args()
     (options, args) = parser.parse_args()

-    verbosity = options.verbosity

     if options.action is None:
     if options.action is None:

-        print parser.format_help()
+        print(parser.format_help())

     elif options.action == 'add':
         if options.item == 'cdrom':
     elif options.action == 'add':
         if options.item == 'cdrom':

-            attrs = dict(zip(('cdrom_id', 'description', 'mirror_id', 'uri_suffix'),
-                             args))
+            attrs = dict(list(zip(('cdrom_id', 'description', 'mirror_id', 'uri_suffix'),
+                                  args)))

             cdrom = database.CDROM(**attrs)
             database.session.add(cdrom)
             database.session.commit()
             cdrom = database.CDROM(**attrs)
             database.session.add(cdrom)
             database.session.commit()

-            
+

             load_image(cdrom)
             load_image(cdrom)

-        
+

         elif options.item == 'mirror':
         elif options.item == 'mirror':

-            attrs = dict(zip(('mirror_id', 'uri_prefix'),
-                             args))
+            attrs = dict(list(zip(('mirror_id', 'uri_prefix'),
+                                  args)))

             mirror = database.Mirror(**attrs)
             database.session.add(mirror)
             database.session.commit()
             mirror = database.Mirror(**attrs)
             database.session.add(mirror)
             database.session.commit()