The criu-ns script creates a new PID namespace where criu is the "init"
process. When using the --restore-detached option with criu-ns, users
expect criu-ns to exit without killing the restored process tree.
Thus, criu-ns should not pass the --restore-detached to criu to prevent
it from terminating, and it should exit instead of waiting for criu's
exit status.
Resolves#1278
Suggested-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
This change extracts some of the duplicated code from
set_pidns() and set_mntns() functions.
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
Raising an exception breaks out of the normal
flow of control of a code block. When an exception
is not handled, the interpreter terminates execution
of the program, or returns to its interactive main loop.
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
criu-ns performs double fork, which results in criu restore
using PID=2. Thus, if a user is trying to restore a process
with that PID, the restore will fail.
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
class ctypes.c_char_p
Represents the C char * datatype when it points to a zero-
terminated string. For a general character pointer that may
also point to binary data, POINTER(c_char) must be used.
The constructor accepts an integer address, or a bytes object.
https://docs.python.org/3/library/ctypes.html#ctypes.c_char_p
Signed-off-by: Radostin Stoyanov <rstoyanov1@gmail.com>
In Py2 `range` returns a list and `xrange` creates a sequence object
that evaluates lazily. In Py3 `range` is equivalent to `xrange` in Py2.
Signed-off-by: Radostin Stoyanov <rstoyanov1@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
So, here's the enhanced version of the first try.
Changes are:
1. The wrapper name is criu-ns instead of crns.py
2. The CLI is absolutely the same as for criu, since the script
re-execl-s criu binary. E.g.
scripts/criu-ns dump -t 1234 ...
just works
3. Caller doesn't need to care about substituting CLI options,
instead, the scripts analyzes the command line and
a) replaces -t|--tree argument with virtual pid __if__ the
target task lives in another pidns
b) keeps the current cwd (and root) __if__ switches to another
mntns. A limitation applies here -- cwd path should be the
same in target ns, no "smart path mapping" is performed. So
this script is for now only useful for mntns clones (which
is our main goal at the moment).
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Looks-good-to: Andrey Vagin <avagin@openvz.org>
