Command to wait a specific state for the container

src/lxc/lxc_wait.c

+/*
+ * lxc: linux Container library
+ *
+ * (C) Copyright IBM Corp. 2007, 2008
+ *
+ * Authors:
+ * Daniel Lezcano <dlezcano at fr.ibm.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include <stdio.h>
+#include <string.h>
+#include <libgen.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+#include <lxc/lxc.h>
+
+void usage(char *cmd)
+{
+	fprintf(stderr, "%s <command>\n", basename(cmd));
+	fprintf(stderr, "\t -n <name>   : name of the container\n");
+	fprintf(stderr, "\t -s <states> : ORed states to wait for STOPPED, " \
+		"STARTING, RUNNING, STOPPING, ABORTING, FREEZING, FROZEN\n");
+	_exit(1);
+}
+
+static int fillwaitedstates(char *strstates, int *states)
+{
+	char *token, *saveptr = NULL;
+	int state;
+
+	token = strtok_r(strstates, "|", &saveptr);
+	while (token) {
+
+		state = lxc_str2state(token);
+		if (state < 0)
+			return -1;
+		states[state] = 1;
+
+		token = strtok_r(NULL, "|", &saveptr);
+		
+	}
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	char opt, *name = NULL, *states = NULL;
+	struct lxc_msg msg;
+	int s[MAX_STATE] = { }, fd;
+
+	while ((opt = getopt(argc, argv, "s:n:")) != -1) {
+		switch (opt) {
+		case 'n':
+			name = optarg;
+			break;
+		case 's':
+			states = optarg;
+			break;
+		}
+	}
+
+	if (!name || !states)
+		usage(argv[0]);
+
+	if (fillwaitedstates(states, s)) {
+		fprintf(stderr, "invalid states specified\n");
+		usage(argv[0]);
+	}
+
+	
+	fd = lxc_monitor_open(name);
+	if (fd < 0) {
+		fprintf(stderr, "failed to open monitor for '%s'\n", name);
+		return -1;
+	}
+
+	for (;;) {
+		if (lxc_monitor_read(fd, &msg) < 0) {
+			fprintf(stderr, 
+				"failed to read monitor's message for '%s'\n", 
+				name);
+			return -1;
+		}
+
+		switch (msg.type) {
+		case lxc_msg_state:
+			if (msg.value < 0 || msg.value >= MAX_STATE) {
+				fprintf(stderr, "Receive an invalid state number '%d'\n", msg.value);
+				return -1;
+			}
+
+			if (s[msg.value])
+				return 0;
+			break;
+		default:
+			printf("invalid msg format\n");
+			break;
+		}
+	}
+
+	return 0;
+}