Move the idmapshift binary into privsep.

I can't see any evidence that anyone else uses our nova-idmapshift
binary, and it adds a lot of complexity (flags we never call for
example). Move the code we do actually use into the privsep
directory and simplify our calls to it. Remove the extra binary
from our install and documentation.

Change-Id: Ibce28d20d166da154833376cf51f1877b829925e
blueprint: hurrah-for-privsep

doc/source/cli/index.rst

@@ -78,7 +78,6 @@ are documented for completeness and debugging if something goes wrong.
    :maxdepth: 1
 
    nova-rootwrap
-   nova-idmapshift
 
 Deprecated Services
 -------------------

doc/source/conf.py

@@ -123,7 +123,6 @@
     ('nova-console', u'Cloud controller fabric'),
     ('nova-consoleauth', u'Cloud controller fabric'),
     ('nova-dhcpbridge', u'Cloud controller fabric'),
-    ('nova-idmapshift', u'Cloud controller fabric'),
     ('nova-manage', u'Cloud controller fabric'),
     ('nova-network', u'Cloud controller fabric'),
     ('nova-novncproxy', u'Cloud controller fabric'),

etc/nova/rootwrap.d/compute.filters

@@ -137,9 +137,6 @@ brctl: CommandFilter, brctl, root
 # nova/virt/xenapi/vm_utils.py: 'mkswap'
 mkswap: CommandFilter, mkswap, root
 
-# nova/virt/libvirt/utils.py: 'nova-idmapshift'
-nova-idmapshift: CommandFilter, nova-idmapshift, root
-
 # nova/virt/xenapi/vm_utils.py: 'mkfs'
 # nova/utils.py: 'mkfs', fs, path, label
 mkfs: CommandFilter, mkfs, root

nova/cmd/idmapshift.py → nova/privsep/idmapshift.py

@@ -11,56 +11,12 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 """
-##########
-IDMapShift
-##########
 
 IDMapShift is a tool that properly sets the ownership of a filesystem for use
 with linux user namespaces.
 
-=====
-Usage
-=====
-
-    nova-idmapshift -i -u 0:10000:2000 -g 0:10000:2000 path
-
-This command will idempotently shift `path` to proper ownership using
-the provided uid and gid mappings.
-
-=========
-Arguments
-=========
-
-    nova-idmapshift -i -c -d -v
-                    -u [[guest-uid:host-uid:count],...]
-                    -g [[guest-gid:host-gid:count],...]
-                    -n [nobody-id]
-                    path
-
-path: Root path of the filesystem to be shifted
-
--i, --idempotent: Shift operation will only be performed if filesystem
-appears unshifted
-
--c, --confirm: Will perform check on filesystem
-Returns 0 when filesystem appears shifted
-Returns 1 when filesystem appears unshifted
-
--d, --dry-run: Print chown operations, but won't perform them
-
--v, --verbose: Print chown operations while performing them
-
--u, --uid: User ID mappings, maximum of 3 ranges
-
--g, --gid: Group ID mappings, maximum of 3 ranges
-
--n, --nobody: ID to map all unmapped uid and gids to.
-
-=======
-Purpose
-=======
-
 When using user namespaces with linux containers, the filesystem of the
 container must be owned by the targeted user and group ids being applied
 to that container. Otherwise, processes inside the container won't be able
@@ -80,12 +36,13 @@
 """
 
 
-import argparse
 import os
-import sys
 
-from nova.i18n import _
+from oslo_log import log as logging
+
+import nova.privsep
 
+LOG = logging.getLogger(__name__)
 NOBODY_ID = 65534
 
 
@@ -102,30 +59,25 @@ def find_target_id(fsid, mappings, nobody, memo):
 
 
 def print_chown(path, uid, gid, target_uid, target_gid):
-    print('%s %s:%s -> %s:%s' % (path, uid, gid, target_uid, target_gid))
+    LOG.debug('%s %s:%s -> %s:%s', path, uid, gid, target_uid, target_gid)
 
 
-def shift_path(path, uid_mappings, gid_mappings, nobody, uid_memo, gid_memo,
-               dry_run=False, verbose=False):
+def shift_path(path, uid_mappings, gid_mappings, nobody, uid_memo, gid_memo):
     stat = os.lstat(path)
     uid = stat.st_uid
     gid = stat.st_gid
     target_uid = find_target_id(uid, uid_mappings, nobody, uid_memo)
     target_gid = find_target_id(gid, gid_mappings, nobody, gid_memo)
-    if verbose:
-        print_chown(path, uid, gid, target_uid, target_gid)
-    if not dry_run:
-        os.lchown(path, target_uid, target_gid)
+    print_chown(path, uid, gid, target_uid, target_gid)
+    os.lchown(path, target_uid, target_gid)
 
 
-def shift_dir(fsdir, uid_mappings, gid_mappings, nobody,
-              dry_run=False, verbose=False):
+def shift_dir(fsdir, uid_mappings, gid_mappings, nobody):
     uid_memo = dict()
     gid_memo = dict()
 
     def shift_path_short(p):
         shift_path(p, uid_mappings, gid_mappings, nobody,
-                   dry_run=dry_run, verbose=verbose,
                    uid_memo=uid_memo, gid_memo=gid_memo)
 
     shift_path_short(fsdir)
@@ -182,51 +134,8 @@ def confirm_dir(fsdir, uid_mappings, gid_mappings, nobody):
     return True
 
 
-def id_map_type(val):
-    maps = val.split(',')
-    id_maps = []
-    for m in maps:
-        map_vals = m.split(':')
-
-        if len(map_vals) != 3:
-            msg = ('Invalid id map %s, correct syntax is '
-                   'guest-id:host-id:count.')
-            raise argparse.ArgumentTypeError(msg % val)
-
-        try:
-            vals = [int(i) for i in map_vals]
-        except ValueError:
-            msg = 'Invalid id map %s, values must be integers' % val
-            raise argparse.ArgumentTypeError(msg)
-
-        id_maps.append(tuple(vals))
-    return id_maps
-
-
-def main():
-    parser = argparse.ArgumentParser(
-                     description=_('nova-idmapshift is a tool that properly '
-                                   'sets the ownership of a filesystem for '
-                                   'use with linux user namespaces.  '
-                                   'This tool can only be used with linux '
-                                   'lxc containers.  See the man page for '
-                                   'details.'))
-    parser.add_argument('path')
-    parser.add_argument('-u', '--uid', type=id_map_type, default=[])
-    parser.add_argument('-g', '--gid', type=id_map_type, default=[])
-    parser.add_argument('-n', '--nobody', default=NOBODY_ID, type=int)
-    parser.add_argument('-i', '--idempotent', action='store_true')
-    parser.add_argument('-c', '--confirm', action='store_true')
-    parser.add_argument('-d', '--dry-run', action='store_true')
-    parser.add_argument('-v', '--verbose', action='store_true')
-    args = parser.parse_args()
-
-    if args.idempotent or args.confirm:
-        if confirm_dir(args.path, args.uid, args.gid, args.nobody):
-            sys.exit(0)
-        else:
-            if args.confirm:
-                sys.exit(1)
-
-    shift_dir(args.path, args.uid, args.gid, args.nobody,
-              dry_run=args.dry_run, verbose=args.verbose)
+@nova.privsep.sys_admin_pctxt.entrypoint
+def shift(path, uid_map, gid_map):
+    if confirm_dir(uid_map, gid_map, path, NOBODY_ID):
+        return
+    shift_dir(path, uid_map, gid_map, NOBODY_ID)