Add -Z, --dry-run option to show which services we would start/stop

without actually doing so.
Fixes #151.

man/runscript.8

@@ -22,7 +22,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd April 26, 2009
+.Dd April 30, 2009
 .Dt RUNSCRIPT 8 SMM
 .Os OpenRC
 .Sh NAME
@@ -33,6 +33,7 @@
 .Op Fl D , -nodeps
 .Op Fl d , -debug
 .Op Fl s , -ifstarted
+.Op Fl Z , -dry-run
 .Op Ar command ...
 .Sh DESCRIPTION
 .Nm
@@ -81,6 +82,9 @@ Turns off all informational output the service generates.
 Output from any non OpenRC comands is not affected.
 .It Fl v , -verbose
 Turns on any extra informational output the service generates.
+.It Fl Z , -dry-run
+Shows what services would be stopped and/or started without actually starting
+or stopping them.
 .El
 .Pp
 The following variables affect the service script:

src/rc/runscript.c

@@ -75,31 +75,18 @@
 #define WAIT_TIMEOUT	60		/* seconds until we timeout */
 #define WARN_TIMEOUT	10		/* warn about this every N seconds */
 
-static const char *applet = NULL;
+static const char *applet;
-static RC_STRINGLIST *applet_list = NULL;
+static char *service, *runlevel, *ibsave, *prefix;;
-static RC_STRINGLIST *restart_services = NULL;
+static RC_DEPTREE *deptree;
-static RC_STRINGLIST *need_services = NULL;
+static RC_STRINGLIST *applet_list, *services, *tmplist;
-static RC_STRINGLIST *use_services = NULL;
+static RC_STRINGLIST *restart_services, *need_services, *use_services;
-static RC_STRINGLIST *services = NULL;
+static RC_HOOK hook_out;
-static RC_STRINGLIST *tmplist = NULL;
+static int exclusive_fd = -1, master_tty = -1;
-static char *service = NULL;
+static bool sighup, in_background, deps, dry_run;
-static int exclusive_fd = -1;
+static pid_t service_pid;
-static RC_DEPTREE *deptree = NULL;
-static char *runlevel = NULL;
-static bool sighup = false;
-static char *ibsave = NULL;
-static bool in_background = false;
-static RC_HOOK hook_out = 0;
-static pid_t service_pid = 0;
-static char *prefix = NULL;
 static int signal_pipe[2] = { -1, -1 };
-static int master_tty = -1;
 
-static RC_STRINGLIST *types_b = NULL;
+static RC_STRINGLIST *types_b, *types_n, *types_nu, *types_nua, *types_m;
-static RC_STRINGLIST *types_n = NULL;
-static RC_STRINGLIST *types_nu = NULL;
-static RC_STRINGLIST *types_nua = NULL;
-static RC_STRINGLIST *types_m = NULL;
 static RC_STRINGLIST *types_mua = NULL;
 
 #ifdef __linux__
@@ -569,26 +556,16 @@ setup_types(void)
 }
 
 static void
-svc_start(bool deps)
+svc_start_check(void)
 {
-	bool started;
-	bool background = false;
-	RC_STRING *svc;
-	RC_STRING *svc2;
-	int depoptions = RC_DEP_TRACE;
 	RC_SERVICE state;
-	bool first;
-	int n;
-	size_t len;
-	char *p;
-	char *tmp;
 
 	state = rc_service_state(service);
 	
-	if (rc_yesno(getenv("IN_HOTPLUG")) || in_background) {
+	if (in_background) {
 		if (!(state & (RC_SERVICE_INACTIVE | RC_SERVICE_STOPPED)))
 			exit(EXIT_FAILURE);
-		background = true;
+		if (rc_yesno(getenv("IN_HOTPLUG")))
 			rc_service_mark(service, RC_SERVICE_HOTPLUGGED);
 		if (strcmp(runlevel, RC_LEVEL_SYSINIT) == 0)
 			ewarnx("WARNING: %s will be started in the"
@@ -611,19 +588,30 @@ svc_start(bool deps)
 	if (state & RC_SERVICE_STARTED) {
 		ewarn("WARNING: %s has already been started", applet);
 		return;
-	} else if (state & RC_SERVICE_INACTIVE && ! background)
+	} else if (state & RC_SERVICE_INACTIVE && !in_background)
 		ewarnx("WARNING: %s has already started, but is inactive",
 		    applet);
 	
 	rc_service_mark(service, RC_SERVICE_STARTING);
 	hook_out = RC_HOOK_SERVICE_START_OUT;
 	rc_plugin_run(RC_HOOK_SERVICE_START_IN, applet);
+}
+
+static void
+svc_start_deps(void)
+{
+	bool first;
+	RC_STRING *svc, *svc2;
+	RC_SERVICE state;
+	int depoptions = RC_DEP_TRACE, n;
+	size_t len;
+	char *p, *tmp;
+	pid_t pid;
 	
 	errno = 0;
 	if (rc_conf_yesno("rc_depend_strict") || errno == ENOENT)
 		depoptions |= RC_DEP_STRICT;
 
-	if (deps) {
 	if (!deptree && ((deptree = _rc_deptree_load(0, NULL)) == NULL))
 		eerrorx("failed to load deptree");
 	if (!types_b)
@@ -648,11 +636,9 @@ svc_start(bool deps)
 	services = NULL;
 
 	need_services = rc_deptree_depends(deptree, types_n,
-		    applet_list,	runlevel,
+	    applet_list, runlevel, depoptions);
-		    depoptions);
 	use_services = rc_deptree_depends(deptree, types_nu,
-		    applet_list, runlevel,
+	    applet_list, runlevel, depoptions);
-		    depoptions);
 
 	if (!rc_runlevel_starting()) {
 		TAILQ_FOREACH(svc, use_services, entries) {
@@ -664,13 +650,20 @@ svc_start(bool deps)
 			    rc_runlevel_starting())
 				continue;
 			if (state & RC_SERVICE_STOPPED) {
-					pid_t pid = service_start(svc->value);
+				if (dry_run) {
+					printf(" %s", svc->value);
+					continue;
+				}
+				pid = service_start(svc->value);
 				if (!rc_conf_yesno("rc_parallel"))
 					rc_waitpid(pid);
 			}
 		}
 	}
 
+	if (dry_run)
+		return;
+
 	/* Now wait for them to start */
 	services = rc_deptree_depends(deptree, types_nua, applet_list,
 	    runlevel, depoptions);
@@ -686,10 +679,8 @@ svc_start(bool deps)
 		if (state & RC_SERVICE_STARTING &&
 		    state & RC_SERVICE_WASINACTIVE)
 		{
-				if (!rc_stringlist_find(need_services,
+			if (!rc_stringlist_find(need_services, svc->value) &&
-					svc->value) &&
+			    !rc_stringlist_find(use_services, svc->value))
-				    !rc_stringlist_find(use_services,
-					svc->value))
 				continue;
 		}
 
@@ -723,11 +714,9 @@ svc_start(bool deps)
 		TAILQ_FOREACH(svc, tmplist, entries) {
 			rc_service_schedule_start(svc->value, service);
 			use_services = rc_deptree_depend(deptree, 
-				    "iprovide",
+			    "iprovide", svc->value);
-				    svc->value);
 			TAILQ_FOREACH(svc2, use_services, entries)
-				    rc_service_schedule_start(svc2->value,
+			    rc_service_schedule_start(svc2->value, service);
-					service);
 			rc_stringlist_free(use_services);
 			use_services = NULL;
 			len += strlen(svc->value) + 2;
@@ -753,6 +742,11 @@ svc_start(bool deps)
 	services = NULL;
 }
 
+static void svc_start_real()
+{
+	bool started;
+	RC_STRING *svc, *svc2;
+	
 	if (ibsave)
 		setenv("IN_BACKGROUND", ibsave, 1);
 	hook_out = RC_HOOK_SERVICE_START_DONE;
@@ -803,20 +797,31 @@ svc_start(bool deps)
 }
 
 static void
-svc_stop(bool deps)
+svc_start(void)
 {
-	bool stopped;
+	if (dry_run)
-	RC_SERVICE state = rc_service_state(service);
+		einfon("start:");
-	int depoptions = RC_DEP_TRACE;
+	else
-	RC_STRING *svc;
+		svc_start_check();
+	if (deps)
+		svc_start_deps();
+	if (dry_run)
+		printf(" %s\n", applet);
+	else
+		svc_start_real();
+}
 
+static void
+svc_stop_check(RC_SERVICE *state)
+{
+	*state = rc_service_state(service);
 
-	if (rc_runlevel_stopping() && state & RC_SERVICE_FAILED)
+	if (rc_runlevel_stopping() && *state & RC_SERVICE_FAILED)
 		exit(EXIT_FAILURE);
 
-	if (rc_yesno(getenv("IN_HOTPLUG")) || in_background)
+	if (in_background &&
-		if (!(state & RC_SERVICE_STARTED) &&
+	    !(*state & RC_SERVICE_STARTED) &&
-		    !(state & RC_SERVICE_INACTIVE))
+	    !(*state & RC_SERVICE_INACTIVE))
 		exit(EXIT_FAILURE);
 
 	if (exclusive_fd == -1)
@@ -824,14 +829,14 @@ svc_stop(bool deps)
 	if (exclusive_fd == -1) {
 		if (errno == EACCES)
 			eerrorx("%s: superuser access required", applet);
-		if (state & RC_SERVICE_STOPPING)
+		if (*state & RC_SERVICE_STOPPING)
 			ewarnx("WARNING: %s is already stopping", applet);
-		eerrorx("ERROR: %s has been stopped by something else", applet);
+		eerrorx("ERROR: %s stopped by something else", applet);
 	}
 	fcntl(exclusive_fd, F_SETFD,
 	    fcntl(exclusive_fd, F_GETFD, 0) | FD_CLOEXEC);
 
-	if (state & RC_SERVICE_STOPPED) {
+	if (*state & RC_SERVICE_STOPPED) {
 		ewarn("WARNING: %s is already stopped", applet);
 		return;
 	}
@@ -846,8 +851,18 @@ svc_stop(bool deps)
 		else if (rc_service_in_runlevel(service, RC_LEVEL_BOOT))
 			ewarn("WARNING: you are stopping a boot service");
 	}
+}
+
+static void
+svc_stop_deps(RC_SERVICE state)
+{
+	int depoptions = RC_DEP_TRACE;
+	RC_STRING *svc;
+	pid_t pid;
+
+	if (state & RC_SERVICE_WASINACTIVE)
+		return;
 	
-	if (deps && !(state & RC_SERVICE_WASINACTIVE)) {
 	errno = 0;
 	if (rc_conf_yesno("rc_depend_strict") || errno == ENOENT)
 		depoptions |= RC_DEP_STRICT;
@@ -872,12 +887,16 @@ svc_stop(bool deps)
 		if (state & RC_SERVICE_STARTED ||
 		    state & RC_SERVICE_INACTIVE)
 		{
+			if (dry_run) {
+				printf(" %s", svc->value);
+				continue;
+			}
 			svc_wait(svc->value);
 			state = rc_service_state(svc->value);
 			if (state & RC_SERVICE_STARTED ||
 			    state & RC_SERVICE_INACTIVE)
 			{
-					pid_t pid = service_stop(svc->value);
+				pid = service_stop(svc->value);
 				if (!rc_conf_yesno("rc_parallel"))
 					rc_waitpid(pid);
 				rc_stringlist_add(tmplist, svc->value);
@@ -886,6 +905,8 @@ svc_stop(bool deps)
 	}
 	rc_stringlist_free(services);
 	services = NULL;
+	if (dry_run)
+		return;
 
 	TAILQ_FOREACH(svc, tmplist, entries) {
 		if (rc_service_state(svc->value) & RC_SERVICE_STOPPED)
@@ -910,7 +931,6 @@ svc_stop(bool deps)
 	rc_stringlist_free(tmplist);
 	tmplist = NULL;
 	
-
 	/* We now wait for other services that may use us and are
 	 * stopping. This is important when a runlevel stops */
 	services = rc_deptree_depends(deptree, types_mua, applet_list,
@@ -924,6 +944,11 @@ svc_stop(bool deps)
 	services = NULL;
 }
 
+static void
+svc_stop_real(void)
+{
+	bool stopped;
+	
 	/* If we're stopping localmount, set LC_ALL=C so that
 	 * bash doesn't load anything blocking the unmounting of /usr */
 	if (strcmp(applet, "localmount") == 0)
@@ -952,7 +977,25 @@ svc_stop(bool deps)
 }
 
 static void
-svc_restart(bool deps)
+svc_stop(void)
+{
+	RC_SERVICE state;
+
+	state = 0;
+	if (dry_run)
+		einfon("stop:");
+	else
+		svc_stop_check(&state);
+	if (deps)
+		svc_stop_deps(state);
+	if (dry_run)
+		printf(" %s\n", applet);
+	else
+		svc_stop_real();
+}
+
+static void
+svc_restart(void)
 {
 	/* This is hairly and a better way needs to be found I think!
 	 * The issue is this - openvpn need net and dns. net can restart
@@ -976,10 +1019,13 @@ svc_restart(bool deps)
 
 	if (!(rc_service_state(service) & RC_SERVICE_STOPPED)) {
 		get_started_services();
-		svc_stop(deps);
+		svc_stop();
+		if (dry_run)
+			ewarn("Cannot calculate restart start dependencies"
+			    " on a dry-run");
 	}
 
-	svc_start(deps);
+	svc_start();
 	start_services(restart_services);
 	rc_stringlist_free(restart_services);
 	restart_services = NULL;
@@ -1018,10 +1064,11 @@ service_plugable(void)
 }
 
 #include "_usage.h"
-#define getoptstring "dDsvl:" getoptstring_COMMON
+#define getoptstring "dDsvl:Z" getoptstring_COMMON
 #define extraopts "stop | start | restart | describe | zap"
 static const struct option longopts[] = {
 	{ "debug",      0, NULL, 'd'},
+	{ "dry-run",    0, NULL, 'Z'},
 	{ "ifstarted",  0, NULL, 's'},
 	{ "nodeps",     0, NULL, 'D'},
 	{ "lockfd",     1, NULL, 'l'},
@@ -1029,6 +1076,7 @@ static const struct option longopts[] = {
 };
 static const char *const longopts_help[] = {
 	"set xtrace when running the script",
+	"show what would be done",
 	"only run commands when started",
 	"ignore dependencies",
 	"fd of the exclusive lock from rc",
@@ -1039,19 +1087,12 @@ static const char *const longopts_help[] = {
 int
 runscript(int argc, char **argv)
 {
-	bool deps = true;
 	bool doneone = false;
-	char pidstr[10];
+	int retval, opt, depoptions = RC_DEP_TRACE;
-	int retval;
-	int opt;
 	RC_STRING *svc;
-	char path[PATH_MAX];
+	char path[PATH_MAX], lnk[PATH_MAX], *dir, *save = NULL, pidstr[10];
-	char lnk[PATH_MAX];
+	size_t l = 0, ll;
-	size_t l = 0;
-	size_t ll;
-	char *dir, *save = NULL;
 	const char *file;
-	int depoptions = RC_DEP_TRACE;
 	struct stat stbuf;
 
 	/* Show help if insufficient args */
@@ -1153,6 +1194,8 @@ runscript(int argc, char **argv)
 	setup_selinux(argc, argv);
 #endif
 
+	deps = true;
+	
 	/* Punt the first arg as it's our service name */
 	argc--;
 	argv++;
@@ -1176,7 +1219,10 @@ runscript(int argc, char **argv)
 		case 'D':
 			deps = false;
 			break;
-			case_RC_COMMON_GETOPT
+		case 'Z':
+			dry_run = true;
+			break;
+			case_RC_COMMON_GETOPT;
 		}
 
 	/* If we're changing runlevels and not called by rc then we cannot
@@ -1196,6 +1242,7 @@ runscript(int argc, char **argv)
 	if (rc_yesno(getenv("IN_HOTPLUG"))) {
 		if (!service_plugable())
 			eerrorx("%s: not allowed to be hotplugged", applet);
+		in_background = true;
 	}
 
 	/* Setup a signal handler */
@@ -1277,15 +1324,15 @@ runscript(int argc, char **argv)
 			{
 				if (rc_service_state(service) &
 				    RC_SERVICE_STARTED)
-					svc_restart(deps);
+					svc_restart();
 			} else if (strcmp(optarg, "restart") == 0) {
-				svc_restart(deps);
+				svc_restart();
 			} else if (strcmp(optarg, "start") == 0) {
-				svc_start(deps);
+				svc_start();
 			} else if (strcmp(optarg, "stop") == 0) {
 				if (deps && in_background)
 					get_started_services();
-				svc_stop(deps);
+				svc_stop();
 				if (deps) {
 					if (!in_background &&
 					    !rc_runlevel_stopping() &&