From 4eba2347c59e6d9818b3ded2eb9d2aa13d5e1780 Mon Sep 17 00:00:00 2001
From: Sebastien Luttringer <sebastien.luttringer@smartjog.com>
Date: Thu, 15 Dec 2011 12:28:06 +0100
Subject: [PATCH] add istrick file in {,un}prepare_chroot functions
prepare and uprepare chroot functions now track non existant files
preparing are now done more carrefully about tricks
---
installsystems/tools.py | 99 +++++++++++++++++++++++++++++------------
1 file changed, 70 insertions(+), 29 deletions(-)
diff --git a/installsystems/tools.py b/installsystems/tools.py
index 757ffd2..c15e189 100644
--- a/installsystems/tools.py
+++ b/installsystems/tools.py
@@ -373,27 +373,38 @@ def prepare_chroot(path, mount=True):
check_call(["mount", "--bind", origin, target], close_fds=True)
except CalledProcessError as e:
warn("Mount failed: %s.\n" % e)
- arrow("Cheating")
+ arrow("Tricks")
+ exists = os.path.exists
+ join = os.path.join
# check path is a kind of linux FHS
- if not os.path.exists(os.path.join(path, "etc")) or not os.path.exists(os.path.join(path, "usr")):
+ if not exists(join(path, "etc")) or not exists(join(path, "usr")):
return
# trick resolv.conf
try:
- if os.path.exists("/etc/resolv.conf"):
+ resolv_path = join(path, "etc", "resolv.conf")
+ resolv_backup_path = join(path, "etc", "resolv.conf.isbackup")
+ resolv_trick_path = join(path, "etc", "resolv.conf.istrick")
+ if (exists("/etc/resolv.conf")
+ and not exists(resolv_backup_path)
+ and not exists(resolv_trick_path)):
arrow("resolv.conf", 1)
- resolv_path = os.path.join(path, "etc", "resolv.conf")
- if os.path.exists(resolv_path):
- os.rename(resolv_path, "%s.isbackup" % resolv_path)
+ if exists(resolv_path):
+ os.rename(resolv_path, resolv_backup_path)
+ else:
+ open(resolv_trick_path, "wb")
shutil.copy("/etc/resolv.conf", resolv_path)
except Exception as e:
warn("resolv.conf tricks fail: %s" % e)
# trick mtab
try:
- mtab_path = os.path.join(path, "etc", "mtab")
- arrow("mtab", 1)
- if os.path.exists(mtab_path):
- os.rename(mtab_path, "%s.isbackup" % mtab_path)
- os.symlink("/proc/self/mounts", mtab_path)
+ mtab_path = join(path, "etc", "mtab")
+ mtab_backup_path = join(path, "etc", "mtab.isbackup")
+ mtab_trick_path = join(path, "etc", "mtab.istrick")
+ if not exists(mtab_backup_path) and not exists(mtab_trick_path):
+ arrow("mtab", 1)
+ if os.path.exists(mtab_path):
+ os.rename(mtab_path, mtab_backup_path)
+ os.symlink("/proc/self/mounts", mtab_path)
except Exception as e:
warn("mtab tricks fail: %s" % e)
# try to guest distro
@@ -402,10 +413,10 @@ def prepare_chroot(path, mount=True):
if distro == "debian":
arrow("Debian specific", 1)
# create a chroot header
- try: open(os.path.join(path, "etc", "debian_chroot"), "w").write("CHROOT")
+ try: open(join(path, "etc", "debian_chroot"), "w").write("CHROOT")
except: pass
# fake policy-rc.d. It must exit 101, it's an expected exitcode.
- policy_path = os.path.join(path, "usr", "sbin", "policy-rc.d")
+ policy_path = join(path, "usr", "sbin", "policy-rc.d")
try: open(policy_path, "w").write("#!/bin/bash\nexit 101\n")
except: pass
# policy-rc.d needs to be executable
@@ -415,38 +426,68 @@ def unprepare_chroot(path, mount=True):
'''
Rollback preparation of a chroot environment inside a directory
'''
- arrow("Uncheating")
+ arrow("Untricks")
+ exists = os.path.exists
+ join = os.path.join
# check path is a kind of linux FHS
- if os.path.exists(os.path.join(path, "etc")) and os.path.exists(os.path.join(path, "usr")):
+ if exists(os.path.join(path, "etc")) and exists(os.path.join(path, "usr")):
# untrick mtab
- mtab_path = os.path.join(path, "etc", "mtab")
- arrow("mtab", 1)
- if os.path.exists(mtab_path):
- os.unlink(mtab_path)
- if os.path.exists("%s.isbackup" % mtab_path):
- os.rename("%s.isbackup" % mtab_path, mtab_path)
+ mtab_path = join(path, "etc", "mtab")
+ mtab_backup_path = join(path, "etc", "mtab.isbackup")
+ mtab_trick_path = join(path, "etc", "mtab.istrick")
+ if exists(mtab_backup_path) or exists(mtab_trick_path):
+ arrow("mtab", 1)
+ # order matter !
+ if exists(mtab_trick_path):
+ try: os.unlink(mtab_path)
+ except OSError: pass
+ try:
+ os.unlink(mtab_trick_path)
+ except OSError:
+ warn("Unable to remove %s" % mtab_trick_path)
+ if exists(mtab_backup_path):
+ try: os.unlink(mtab_path)
+ except OSError: pass
+ try:
+ os.rename(mtab_backup_path, mtab_path)
+ except OSError:
+ warn("Unable to restore %s" % mtab_backup_path)
+
# untrick resolv.conf
- if os.path.exists("/etc/resolv.conf"):
+ resolv_path = join(path, "etc", "resolv.conf")
+ resolv_backup_path = join(path, "etc", "resolv.conf.isbackup")
+ resolv_trick_path = join(path, "etc", "resolv.conf.istrick")
+ if exists(resolv_backup_path) or exists(resolv_trick_path):
arrow("resolv.conf", 1)
- resolv_path = os.path.join(path, "etc", "resolv.conf")
- if os.path.exists(resolv_path):
- os.unlink(resolv_path)
- if os.path.exists("%s.isbackup" % resolv_path):
- os.rename("%s.isbackup" % resolv_path, resolv_path)
+ # order matter !
+ if exists(resolv_trick_path):
+ try: os.unlink(resolv_path)
+ except OSError: pass
+ try:
+ os.unlink(resolv_trick_path)
+ except OSError:
+ warn("Unable to remove %s" % resolv_trick_path)
+ if exists(resolv_backup_path):
+ try: os.unlink(resolv_path)
+ except OSError: pass
+ try:
+ os.rename(resolv_backup_path, resolv_path)
+ except OSError:
+ warn("Unable to restore %s" % resolv_backup_path)
# try to guest distro
distro = guess_distro(path)
# cleaning debian stuff
if distro == "debian":
arrow("Debian specific", 1)
for f in ("etc/debian_chroot", "usr/sbin/policy-rc.d"):
- try: os.unlink(os.path.join(path, f))
+ try: os.unlink(join(path, f))
except: pass
# unmounting
if mount:
mps = ("proc", "sys", "dev", "dev/pts", "dev/shm")
arrow("Unmouting filesystems")
for mp in reversed(mps):
- target = os.path.join(path, mp)
+ target = join(path, mp)
if os.path.ismount(target):
arrow(target, 1)
call(["umount", target], close_fds=True)
--
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