Commit 4eba2347 authored by Sebastien Luttringer's avatar Sebastien Luttringer
Browse files

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
parent 1a802392

installsystems/tools.py

+70 −29
Original line number Diff line number Diff line
@@ -373,26 +373,37 @@ 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")

        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, "%s.isbackup" % 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)
@@ -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")

        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)

        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)

            # 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)