[Code-review] Make $SAR/instance <- $HOME.

[Michael Stone]

In particular, update rainbow-replay-spool and gc.py to deal with the
uid_to_gid table and correctly handle the effects of RAINBOW_CONSTANT_UID.
---
 rainbow/bin/rainbow-replay-spool |    8 ++------
 rainbow/rainbow/gc.py            |    9 ++++-----
 rainbow/rainbow/inject.py        |   36 +++++++++++++++++-------------------
 3 files changed, 23 insertions(+), 30 deletions(-)

diff --git a/rainbow/bin/rainbow-replay-spool b/rainbow/bin/rainbow-replay-spool
index 9acbe99..336521b 100755
--- a/rainbow/bin/rainbow-replay-spool
+++ b/rainbow/bin/rainbow-replay-spool
@@ -1,13 +1,9 @@
 #!/usr/bin/env python
 
-from stat import ST_GID
-from os import listdir, stat
+from os import listdir
 from os.path import join, basename, realpath, exists
 from subprocess import check_call, CalledProcessError
 
-def get_gid(path):
-    return str(stat(path)[ST_GID])
-
 def replay_spool(spool, autocommit):
     if not exists(spool):
         return
@@ -34,7 +30,7 @@ def replay_spool(spool, autocommit):
     # Install our users.
     for uid in listdir(join(spool, 'uid_pool')):
         home = join(spool, 'uid_to_home_dir', uid)
-        gid  = get_gid(home)
+        gid  = basename(realpath(join(spool, 'uid_to_gid', uid)))
         bundle_id = gid__bundle_id[gid]
 
         comment = '%s.%s' % (bundle_id, uid)
diff --git a/rainbow/rainbow/gc.py b/rainbow/rainbow/gc.py
index e7191fe..5edacf3 100644
--- a/rainbow/rainbow/gc.py
+++ b/rainbow/rainbow/gc.py
@@ -1,6 +1,6 @@
 from subprocess import call, check_call, CalledProcessError
 from os import listdir, unlink
-from os.path import join, isdir, islink, exists
+from os.path import join, isdir, islink, exists, lexists
 from .util import trace
 
 def active_uid(uid):
@@ -26,11 +26,10 @@ def gc_uid(spool, uid):
     if active_uid(uid):
         return
 
-    for table in ('uid_to_instance_dir', 'uid_to_home_dir'):
+    for table in ('uid_to_instance_dir', 'uid_to_home_dir', 'uid_to_gid'):
         row = join(spool, table, uid)
-        if exists(row):
-            assert isdir(row) and not islink(row)
-            check_call(['/bin/rm', '-r', '-f', row])
+        # NB: it is important that rm -rf doesn't follow links. <MS>
+        check_call(['/bin/rm', '-r', '-f', row])
 
     # XXX: without -r or -f, we leak mail spools + ?
     # XXX: Userdel is also going to try to delete our groups for us too. Grr.
diff --git a/rainbow/rainbow/inject.py b/rainbow/rainbow/inject.py
index ad05626..a4e4433 100644
--- a/rainbow/rainbow/inject.py
+++ b/rainbow/rainbow/inject.py
@@ -1,6 +1,6 @@
 import os
 from os import F_OK, R_OK, W_OK, X_OK
-from os.path import join, dirname, isabs, basename, realpath, lexists
+from os.path import join, dirname, isabs, basename, realpath, lexists, islink
 import sys
 from stat import S_IFDIR
 import shutil
@@ -117,9 +117,16 @@ def reserve_credentials(log, spool, bundle_id, constant_uid):
     uid = constant_uid and gid or reserve_elt(join(spool, 'uid_pool'), 10000, 65534, 2, 'uids')
     open(join(spool, 'uid_pool', str(gid)), 'w').close()
     log('reserved credentials (%d, %d)', uid, gid)
+
+    path = join(spool, 'uid_to_gid', str(uid))
+    if not lexists(path):
+        os.symlink(str(gid), path)
+    else:
+        assert islink(path) and os.readlink(path) == str(gid)
+
     return (uid, gid)
 
-def grab_home(log, spool, bundle_id, uid, gid, owner_uid):
+def grab_home(log, spool, bundle_id, uid, gid, owner_gid):
     home = join(spool, 'uid_to_home_dir', str(uid))
     comment = '%s.%d' % (bundle_id, uid)
 
@@ -142,18 +149,16 @@ def grab_home(log, spool, bundle_id, uid, gid, owner_uid):
         else:
             raise e
 
-    os.chown(home, owner_uid, gid)
-    os.chmod(home, 0750)
+    os.chown(home, uid, owner_gid)
+    os.chmod(home, 0770)
 
     return home
 
 def configure_home(spool, owner_uid, owner_gid, uid, gid, home):
     path = join(spool, 'uid_to_instance_dir', str(uid))
-    make_dirs(path, uid, owner_gid, 0770)
-    os.chown(path, uid, owner_gid)
-    os.chmod(path, 0770)
+    os.symlink(home, path)
     if not lexists(join(home, 'instance')):
-        os.symlink(path, join(home, 'instance'))
+        os.symlink('.', join(home, 'instance'))
 
     path = join(spool, 'gid_to_data_dir', str(gid))
     make_dirs(path, owner_uid, gid, 0770)
@@ -179,13 +184,6 @@ def configure_home(spool, owner_uid, owner_gid, uid, gid, home):
         os.chown(join(home, path), uid, owner_gid)
         os.chmod(join(home, path), 0770)
 
-    if not lexists(join(home, '.fontconfig')):
-        os.symlink('instance', join(home, '.fontconfig'))
-    if not lexists(join(home, '.macromedia')):
-        os.symlink('instance', join(home, '.macromedia'))
-    if not lexists(join(home, '.adobe')):
-        os.symlink('instance', join(home, '.adobe'))
-
 def launch(log, home, uid, gid, argv, env, cwd, pset, safe_fds, strace_hint,
            preloader_hint):
     env['USER'] = str(uid)
@@ -297,7 +295,8 @@ def check_cwd(uid, gid, cwd):
 
 def check_spool(spool, owner_uid, owner_gid):
     spool_dirs = ('uid_pool', 'gid_pool', 'bundle_id_to_gid',
-                 'uid_to_instance_dir', 'gid_to_data_dir', 'uid_to_home_dir')
+                 'uid_to_instance_dir', 'gid_to_data_dir', 'uid_to_home_dir',
+                 'uid_to_gid')
     for frag in spool_dirs:
         make_dirs(join(spool, frag), owner_uid, owner_gid, 0775)
         ck = Checker(join(spool, frag), owner_uid, owner_gid)
@@ -313,8 +312,7 @@ def check_home_dirs(uid, gid, home):
 
 def check_home(uid, gid, home):
     ck = Checker(home, uid, gid)
-    assert ck.positive(R_OK | X_OK, S_IFDIR)
-    assert ck.negative(W_OK, 0)
+    assert ck.positive(R_OK | W_OK | X_OK, S_IFDIR)
 
 def run(log, spool, env, argv, cwd, pset, safe_fds, strace_hint,
         owner_uid, owner_gid, bundle_path, bundle_id, constant_uid,
@@ -328,7 +326,7 @@ def run(log, spool, env, argv, cwd, pset, safe_fds, strace_hint,
     check_spool(spool, owner_uid, owner_gid)
 
     uid, gid = reserve_credentials(log, spool, bundle_id, constant_uid)
-    home = grab_home(log, spool, bundle_id, uid, gid, owner_uid)
+    home = grab_home(log, spool, bundle_id, uid, gid, owner_gid)
     configure_home(spool, owner_uid, owner_gid, uid, gid, home)
 
     if cwd is None:
-- 
1.5.3.3