[lxc-devel] [PATCH 4/4] Enable lxc_fini() to destroy container on shutdown

[Serge Hallyn]

Quoting Christian Brauner (christianvanbrauner at gmail.com):
> When lxc.ephemeral is set to 1 in the containers config it will be destroyed on
> shutdown.
> 
> Signed-off-by: Christian Brauner <christianvanbrauner at gmail.com>

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

> ---
>  src/lxc/start.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 58 insertions(+)
> 
> diff --git a/src/lxc/start.c b/src/lxc/start.c
> index ffb8d12..8fe08a1 100644
> --- a/src/lxc/start.c
> +++ b/src/lxc/start.c
> @@ -83,6 +83,11 @@ const struct ns_info ns_info[LXC_NS_MAX] = {
>  	[LXC_NS_NET] = {"net", CLONE_NEWNET}
>  };
>  
> +static bool do_destroy_container(struct lxc_conf *conf);
> +static int lxc_rmdir_onedev_wrapper(void *data);
> +static void lxc_destroy_container_on_signal(struct lxc_handler *handler,
> +					    const char *name);
> +
>  static void print_top_failing_dir(const char *path)
>  {
>  	size_t len = strlen(path);
> @@ -495,6 +500,9 @@ void lxc_fini(const char *name, struct lxc_handler *handler)
>  		close(handler->ttysock[0]);
>  		close(handler->ttysock[1]);
>  	}
> +	if (handler->conf->ephemeral == 1) {
> +		lxc_destroy_container_on_signal(handler, name);
> +	}
>  	cgroup_destroy(handler);
>  	free(handler);
>  }
> @@ -1291,3 +1299,53 @@ int lxc_start(const char *name, char *const argv[], struct lxc_conf *conf,
>  	conf->need_utmp_watch = 1;
>  	return __lxc_start(name, conf, &start_ops, &start_arg, lxcpath, backgrounded);
>  }
> +
> +static void lxc_destroy_container_on_signal(struct lxc_handler *handler,
> +					    const char *name)
> +{
> +	char destroy[MAXPATHLEN];
> +	bool bret = true;
> +	int ret = 0;
> +	if (handler->conf && handler->conf->rootfs.path && handler->conf->rootfs.mount) {
> +		bret = do_destroy_container(handler->conf);
> +		if (!bret) {
> +			ERROR("Error destroying rootfs for %s", name);
> +			return;
> +		}
> +	}
> +	INFO("Destroyed rootfs for %s", name);
> +
> +	ret = snprintf(destroy, MAXPATHLEN, "%s/%s", handler->lxcpath, name);
> +	if (ret < 0 || ret >= MAXPATHLEN) {
> +		ERROR("Error printing path for %s", name);
> +		ERROR("Error destroying directory for %s", name);
> +		return;
> +	}
> +
> +	if (am_unpriv())
> +		ret = userns_exec_1(handler->conf, lxc_rmdir_onedev_wrapper, destroy);
> +	else
> +		ret = lxc_rmdir_onedev(destroy, NULL);
> +
> +	if (ret < 0) {
> +		ERROR("Error destroying directory for %s", name);
> +		return;
> +	}
> +	INFO("Destroyed directory for %s", name);
> +}
> +
> +static int lxc_rmdir_onedev_wrapper(void *data)
> +{
> +	char *arg = (char *) data;
> +	return lxc_rmdir_onedev(arg, NULL);
> +}
> +
> +static bool do_destroy_container(struct lxc_conf *conf) {
> +        if (am_unpriv()) {
> +                if (userns_exec_1(conf, bdev_destroy_wrapper, conf) < 0)
> +                        return false;
> +                return true;
> +        }
> +        return bdev_destroy(conf);
> +}
> +
> -- 
> 2.5.1
>