[lxc-devel] [PATCH] python3: Allow setting daemonize and close_fds

[Serge Hallyn]

Quoting Stéphane Graber (stgraber at ubuntu.com):
> This extends the list of arguments of start() allowing the user to
> request the container be started in the foreground and have control on
> whether fds will be closed or not (daemonize=True implies that too).
> 
> One problem at the moment however is that while we have functions to set
> close_fds and daemonize in the API, we don't have functions to unset
> those flags, so those new parameters will only work on the initial call
> to start() any further call will use the values of the previous one.
> 
> I think it'd make sense to change lxcapi slightly to have daemonize and
> close_fds offer a similar interface, both returning booleans and both
> accepting a value as a parameter so API users can set the value they
> want.

What would be the point in checking the value as opposed to simply
setting the one you want?

If unsetting is all we need, we could just add a boolean argument to
want_damonize and want_close_all_fds.  If there is a good reason to
be able to check the values, then we can either add a get_daemonize,
or make the second argument to want_daemonize an int, where -1 means
unset, 1 means set, and 0 means just give me the return value.

Or maybe we want to just add new api fns so as not to change the
existing api?  I'm feeling indecisive.

> Signed-off-by: Stéphane Graber <stgraber at ubuntu.com>

Acked-by: Serge E. Hallyn <serge.hallyn at ubuntu.com>

> ---
>  src/python-lxc/lxc.c | 33 +++++++++++++++++++++++++--------
>  1 file changed, 25 insertions(+), 8 deletions(-)
> 
> diff --git a/src/python-lxc/lxc.c b/src/python-lxc/lxc.c
> index f850a3d..5a20ff4 100644
> --- a/src/python-lxc/lxc.c
> +++ b/src/python-lxc/lxc.c
> @@ -1221,13 +1221,21 @@ Container_snapshot_restore(Container *self, PyObject *args, PyObject *kwds)
>  static PyObject *
>  Container_start(Container *self, PyObject *args, PyObject *kwds)
>  {
> +    PyObject *useinit = NULL;
> +    PyObject *daemonize = NULL;
> +    PyObject *close_fds = NULL;
> +
> +    PyObject *vargs = NULL;
>      char** init_args = {NULL};
> -    PyObject *useinit = NULL, *retval = NULL, *vargs = NULL;
> +
> +    PyObject *retval = NULL;
>      int init_useinit = 0, i = 0;
> -    static char *kwlist[] = {"useinit", "cmd", NULL};
> +    static char *kwlist[] = {"useinit", "daemonize", "close_fds",
> +                             "cmd", NULL};
>  
> -    if (! PyArg_ParseTupleAndKeywords(args, kwds, "|OO", kwlist,
> -                                      &useinit, &vargs))
> +    if (! PyArg_ParseTupleAndKeywords(args, kwds, "|OOOO", kwlist,
> +                                      &useinit, &daemonize, &close_fds,
> +                                      &vargs))
>          return NULL;
>  
>      if (useinit && useinit == Py_True) {
> @@ -1241,7 +1249,13 @@ Container_start(Container *self, PyObject *args, PyObject *kwds)
>          }
>      }
>  
> -    self->container->want_daemonize(self->container);
> +    if (close_fds && close_fds == Py_True) {
> +        self->container->want_close_all_fds(self->container);
> +    }
> +
> +    if (!daemonize || daemonize == Py_True) {
> +        self->container->want_daemonize(self->container);
> +    }
>  
>      if (self->container->start(self->container, init_useinit, init_args))
>          retval = Py_True;
> @@ -1519,10 +1533,13 @@ static PyMethodDef Container_methods[] = {
>      },
>      {"start", (PyCFunction)Container_start,
>       METH_VARARGS|METH_KEYWORDS,
> -     "start(useinit = False, cmd = (,)) -> boolean\n"
> +     "start(useinit = False, daemonize=True, close_fds=False, "
> +     "cmd = (,)) -> boolean\n"
>       "\n"
> -     "Start the container, optionally using lxc-init and "
> -     "an alternate init command, then returns its return code."
> +     "Start the container, return True on success.\n"
> +     "When set useinit will make LXC use lxc-init to start the container.\n"
> +     "The container can be started in the foreground with daemonize=False.\n"
> +     "All fds may also be closed by passing close_fds=True."
>      },
>      {"stop", (PyCFunction)Container_stop,
>       METH_NOARGS,
> -- 
> 1.8.4.4
> 
> 
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