shutdown: Rework API and lxc-stop

With this change, shutdown() will no longer call stop() after the
timeout, instead it'll just return false and it's up to the caller to
then call stop() if appropriate.

This also updates the bindings, tests and other scripts.

lxc-stop is then updated to do proper option checking and use shutdown,
stop or reboot as appropriate.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

src/lxc/lxc-start-ephemeral.in

@@ -270,7 +270,8 @@ if not dest.start() or not dest.wait("RUNNING", timeout=5):
 # Deal with the case where we just attach to the container's console
 if not args.command and not args.daemon:
     dest.console()
-    dest.shutdown(timeout=5)
+    if not dest.shutdown(timeout=5):
+        dest.stop()
     sys.exit(0)
 
 # Try to get the IP addresses
@@ -318,6 +319,7 @@ for ip in ips:
     break
 
 # Shutdown the container
-dest.shutdown(timeout=5)
+if not dest.shutdown(timeout=5):
+    dest.stop()
 
 sys.exit(retval)

src/lxc/lxc_stop.c

@@ -77,7 +77,7 @@ Options :\n\
 	.options  = my_longopts,
 	.parser   = my_parser,
 	.checker  = NULL,
-	.timeout = 60,
+	.timeout  = -2,
 };
 
 /* returns -1 on failure, 0 on success */
@@ -95,7 +95,7 @@ static int do_reboot_and_check(struct lxc_arguments *a, struct lxc_container *c)
 		return -1;
 	if (a->nowait)
 		return 0;
-	if (timeout <= 0)
+	if (timeout == 0)
 		goto out;
 
 	for (;;) {
@@ -118,7 +118,7 @@ static int do_reboot_and_check(struct lxc_arguments *a, struct lxc_container *c)
 		if (ret)
 			break;
 		elapsed_time = tv.tv_sec - curtime;
-		if (timeout - elapsed_time <= 0)
+		if (timeout != -1 && timeout - elapsed_time <= 0)
 			break;
 		timeout -= elapsed_time;
 	}
@@ -145,6 +145,46 @@ int main(int argc, char *argv[])
 			 my_args.progname, my_args.quiet, my_args.lxcpath[0]))
 		return 1;
 
+	/* Set default timeout */
+	if (my_args.timeout == -2) {
+		if (my_args.hardstop) {
+			my_args.timeout = 0;
+		}
+		else {
+			my_args.timeout = 60;
+		}
+	}
+
+	if (my_args.nowait) {
+		my_args.timeout = 0;
+	}
+
+	/* some checks */
+	if (!my_args.hardstop && my_args.timeout < -1) {
+		fprintf(stderr, "invalid timeout\n");
+		return 1;
+	}
+
+	if (my_args.hardstop && my_args.nokill) {
+		fprintf(stderr, "-k can't be used with --nokill\n");
+		return 1;
+	}
+
+	if (my_args.hardstop && my_args.reboot) {
+		fprintf(stderr, "-k can't be used with -r\n");
+		return 1;
+	}
+
+	if (my_args.hardstop && my_args.timeout) {
+		fprintf(stderr, "-k doesn't allow timeouts\n");
+		return 1;
+	}
+
+	if (my_args.nolock && !my_args.hardstop) {
+		fprintf(stderr, "--nolock may only be used with -k\n");
+		return 1;
+	}
+
 	/* shortcut - if locking is bogus, we should be able to kill
 	 * containers at least */
 	if (my_args.nolock)
@@ -167,24 +207,27 @@ int main(int argc, char *argv[])
 		goto out;
 	}
 
+	/* kill */
 	if (my_args.hardstop) {
 		ret = c->stop(c) ? 0 : 1;
 		goto out;
 	}
+
+	/* reboot */
 	if (my_args.reboot) {
 		ret = do_reboot_and_check(&my_args, c);
 		goto out;
 	}
 
-	if (my_args.nokill)
-		my_args.timeout = 0;
-
+	/* shutdown */
 	s = c->shutdown(c, my_args.timeout);
 	if (!s) {
-		if (!my_args.shutdown)
-			ret = c->wait(c, "STOPPED", -1) ? 0 : 1;
+		if (my_args.timeout == 0)
+			ret = 0;
+		else if (my_args.nokill)
+			ret = 1;
 		else
-			ret = 1; // fail
+			ret = c->stop(c) ? 0 : 1;
 	} else
 		ret = 0;
 

src/lxc/lxccontainer.c

@@ -1348,10 +1348,6 @@ static bool lxcapi_shutdown(struct lxc_container *c, int timeout)
 		haltsignal = c->lxc_conf->haltsignal;
 	kill(pid, haltsignal);
 	retv = c->wait(c, "STOPPED", timeout);
-	if (!retv && timeout > 0) {
-		c->stop(c);
-		retv = c->wait(c, "STOPPED", 0); // 0 means don't wait
-	}
 	return retv;
 }
 

src/lxc/lxccontainer.h

@@ -362,12 +362,10 @@ struct lxc_container {
 	 * SIGPWR.
 	 *
 	 * \param c Container.
-	 * \param timeout Seconds to wait before forcing a hard stop
-	 *  (value must be >0).
+	 * \param timeout Seconds to wait before returning false.
+	 *  (-1 to wait forever, 0 to avoid waiting).
 	 *
-	 * \return \c true if configuration was loaded successfully, else \c false.
-	 *
-	 * \note A \p timeout of \c 0 means do not wait.
+	 * \return \c true if the container was shutdown successfully, else \c false.
 	 */
 	bool (*shutdown)(struct lxc_container *c, int timeout);
 

src/python-lxc/examples/api_test.py

@@ -144,7 +144,8 @@ if len(sys.argv) > 1 and sys.argv[1] == "--with-console":
 
 ## Shutting down the container
 print("Shutting down the container")
-container.shutdown(3)
+if not container.shutdown(3):
+    container.stop()
 
 if container.running:
     print("Stopping the container")

src/python-lxc/lxc.c

@@ -1591,9 +1591,8 @@ static PyMethodDef Container_methods[] = {
      METH_VARARGS|METH_KEYWORDS,
      "shutdown(timeout = -1) -> boolean\n"
      "\n"
-     "Sends SIGPWR to the container and wait for it to shutdown "
-     "unless timeout is set to a positive value, in which case "
-     "the container will be killed when the timeout is reached."
+     "Sends SIGPWR to the container and wait for it to shutdown."
+     "-1 means wait forever, 0 means skip waiting."
     },
     {"snapshot", (PyCFunction)Container_snapshot,
      METH_VARARGS|METH_KEYWORDS,

src/tests/shutdowntest.c

@@ -69,6 +69,9 @@ int main(int argc, char *argv[])
 		goto out;
 	}
 
+	/* Wait for init to be ready for SIGPWR */
+	sleep(10);
+
 	if (!c->shutdown(c, 60)) {
 		fprintf(stderr, "%d: failed to shut down %s\n", __LINE__, MYNAME);
 		goto out;