ovs-vswitchd: Make database socket command-line argument optional.

In practice the default location is the only one used, so we might as well
make it easy.

3 files changed, 24 insertions, 18 deletions

diff --git a/INSTALL.Linux b/INSTALL.Linux
index 6442fcc9b..6c17ca498 100644
--- a/INSTALL.Linux
+++ b/INSTALL.Linux
@@ -287,8 +287,7 @@ ovsdb-tool (but running it at any time is harmless):
 Then start the main Open vSwitch daemon, telling it to connect to the
 same Unix domain socket:
 
-      % ovs-vswitchd unix:/usr/local/var/run/openvswitch/db.sock \
-            --pidfile --detach 
+      % ovs-vswitchd --pidfile --detach
 
 Now you may use ovs-vsctl to set up bridges and other Open vSwitch
 features.  For example, to create a bridge named br0 and add ports
diff --git a/vswitchd/ovs-vswitchd.8.in b/vswitchd/ovs-vswitchd.8.in
index 3e41babd1..516e6da77 100644
--- a/vswitchd/ovs-vswitchd.8.in
+++ b/vswitchd/ovs-vswitchd.8.in
@@ -14,17 +14,15 @@
 ovs\-vswitchd \- Open vSwitch daemon
 .
 .SH SYNOPSIS
-.B ovs\-vswitchd
-\fIdatabase\fR
+\fBovs\-vswitchd \fR[\fIdatabase\fR]
 .
 .SH DESCRIPTION
 A daemon that manages and controls any number of Open vSwitch switches
 on the local machine.
 .PP
-The mandatory \fIdatabase\fR argument normally takes the form
-\fBunix:\fIfile\fR, where \fIfile\fR is the name of a Unix domain
-socket on which \fBovsdb\-server\fR is listening.  However, all of the
-following forms are accepted:
+The \fIdatabase\fR argument specifies how \fBovs\-vswitchd\fR connects
+to \fBovsdb\-server\fR.  The default is \fBunix:@RUNDIR@/db.sock\fR.
+The following forms are accepted:
 .so ovsdb/remote-active.man
 .so ovsdb/remote-passive.man
 .PP
diff --git a/vswitchd/ovs-vswitchd.c b/vswitchd/ovs-vswitchd.c
index a71eecccc..7d4e4d770 100644
--- a/vswitchd/ovs-vswitchd.c
+++ b/vswitchd/ovs-vswitchd.c
@@ -30,6 +30,7 @@
 #include "command-line.h"
 #include "compiler.h"
 #include "daemon.h"
+#include "dirs.h"
 #include "dummy.h"
 #include "leak-checker.h"
 #include "netdev.h"
@@ -52,7 +53,7 @@ VLOG_DEFINE_THIS_MODULE(vswitchd);
 
 static unixctl_cb_func ovs_vswitchd_exit;
 
-static const char *parse_options(int argc, char *argv[]);
+static char *parse_options(int argc, char *argv[]);
 static void usage(void) NO_RETURN;
 
 int
@@ -60,7 +61,7 @@ main(int argc, char *argv[])
 {
     struct unixctl_server *unixctl;
     struct signal *sighup;
-    const char *remote;
+    char *remote;
     bool exiting;
     int retval;
 
@@ -82,6 +83,8 @@ main(int argc, char *argv[])
     unixctl_command_register("exit", ovs_vswitchd_exit, &exiting);
 
     bridge_init(remote);
+    free(remote);
+
     exiting = false;
     while (!exiting) {
         if (signal_poll(sighup)) {
@@ -107,7 +110,7 @@ main(int argc, char *argv[])
     return 0;
 }
 
-static const char *
+static char *
 parse_options(int argc, char *argv[])
 {
     enum {
@@ -190,21 +193,27 @@ parse_options(int argc, char *argv[])
     argc -= optind;
     argv += optind;
 
-    if (argc != 1) {
-        VLOG_FATAL("database socket is only non-option argument; "
+    switch (argc) {
+    case 0:
+        return xasprintf("unix:%s/db.sock", ovs_rundir());
+
+    case 1:
+        return xstrdup(argv[0]);
+
+    default:
+        VLOG_FATAL("at most one non-option argument accepted; "
                    "use --help for usage");
     }
-
-    return argv[0];
 }
 
 static void
 usage(void)
 {
     printf("%s: Open vSwitch daemon\n"
-           "usage: %s [OPTIONS] DATABASE\n"
-           "where DATABASE is a socket on which ovsdb-server is listening.\n",
-           program_name, program_name);
+           "usage: %s [OPTIONS] [DATABASE]\n"
+           "where DATABASE is a socket on which ovsdb-server is listening\n"
+           "      (default: \"unix:%s/db.sock\").\n",
+           program_name, program_name, ovs_rundir());
     stream_usage("DATABASE", true, false, true);
     daemon_usage();
     vlog_usage();