vnstat2: fix all interfaces being monitored when none are configured

By default, vnstatd adds all available interfaces on startup when its
database is empty. The --noadd option prevents this, but it breaks
import of legacy databases, and causes vnstatd to exit immediately
after startup, which breaks reloading.

This changes the init script to add the --noadd option when no legacy
databases need to be imported, and patches vnstatd to keep running
even when no interfaces are configured.

Signed-off-by: Jan Hoffmann <jan@3e8.eu>

net/vnstat2/Makefile

@@ -7,7 +7,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=vnstat2
 PKG_VERSION:=2.8
-PKG_RELEASE:=1
+PKG_RELEASE:=$(AUTORELEASE)
 
 PKG_SOURCE:=vnstat-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://humdi.net/vnstat

net/vnstat2/files/vnstat.init

@@ -11,13 +11,19 @@ vnstat_option() {
 }
 
 init_database() {
-	local lib="$(vnstat_option DatabaseDir)"
+	local lib database_count
 
-	local database_count="$(ls "$lib" 2>/dev/null | wc -l)"
+	lib="$(vnstat_option DatabaseDir)"
+	[ -n "$lib" ] || lib="/var/lib/vnstat"
+
+	database_count="$(ls "$lib" 2>/dev/null | wc -l)"
 
 	# only init database when folder is empty, as it would prevent import of legacy databases
 	if [ "$database_count" -eq "0" ]; then
 		/usr/sbin/vnstatd --initdb >/dev/null
+	else
+		# if vnstat.db doesn't exist, there are legacy databases to import
+		[ ! -f "$lib/vnstat.db" ] && echo -n "1"
 	fi
 }
 
@@ -31,12 +37,15 @@ init_ifaces() {
 	}
 
 	config_list_foreach "$cfg" interface init_iface
-
-	return 1
 }
 
 start_service() {
-	init_database
+	local options needs_import
+
+	needs_import="$(init_database)"
+
+	# --noadd would prevent import of legacy databases
+	[ -z "$needs_import" ] && options="--noadd --noexit"
 
 	config_load vnstat
 	config_foreach init_ifaces vnstat
@@ -44,7 +53,7 @@ start_service() {
 	procd_open_instance
 	procd_set_param stdout 1
 	procd_set_param stderr 1
-	procd_set_param command /usr/sbin/vnstatd --nodaemon
+	procd_set_param command /usr/sbin/vnstatd --nodaemon $options
 	procd_set_param file /etc/vnstat.conf
 	procd_set_param respawn
 	procd_close_instance

net/vnstat2/patches/100-noexit.patch

@@ -0,0 +1,60 @@
+--- a/src/daemon.c
++++ b/src/daemon.c
+@@ -252,6 +252,7 @@ void initdstate(DSTATE *s)
+ 	s->sync = 0;
+ 	s->forcesave = 0;
+ 	s->noadd = 0;
++	s->noexit = 0;
+ 	s->initdb = 0;
+ 	s->iflisthash = 0;
+ 	s->cfgfile[0] = '\0';
+@@ -282,6 +283,9 @@ void preparedatabase(DSTATE *s)
+ 	}
+ 
+ 	if (s->noadd) {
++		if (s->noexit) {
++			return;
++		}
+ 		printf("No interfaces found in database, exiting.\n");
+ 		exit(EXIT_FAILURE);
+ 	}
+@@ -300,6 +304,9 @@ void preparedatabase(DSTATE *s)
+ 	}
+ 
+ 	if (!addinterfaces(s) && s->dbifcount == 0) {
++		if (s->noexit) {
++			return;
++		}
+ 		printf("Nothing to do, exiting.\n");
+ 		exit(EXIT_FAILURE);
+ 	}
+--- a/src/daemon.h
++++ b/src/daemon.h
+@@ -4,7 +4,7 @@
+ typedef struct {
+ 	int updateinterval, saveinterval;
+ 	short running, dodbsave, rundaemon;
+-	short dbsaved, showhelp, sync, forcesave, noadd, initdb;
++	short dbsaved, showhelp, sync, forcesave, noadd, noexit, initdb;
+ 	short bootdetected, cleanuphour, dbretrycount;
+ 	uint32_t iflisthash;
+ 	uint64_t dbifcount;
+--- a/src/vnstatd.c
++++ b/src/vnstatd.c
+@@ -248,6 +248,7 @@ void showhelp(void)
+ 	printf("      --config <config file>   select used config file\n");
+ 	printf("      --noadd                  prevent startup if database has no interfaces\n");
+ 	printf("      --alwaysadd [mode]       automatically start monitoring all new interfaces\n");
++	printf("      --noexit                 keep running even when database has no interfaces\n");
+ 	printf("      --initdb                 create empty database and exit\n\n");
+ 
+ 	printf("See also \"man vnstatd\".\n");
+@@ -319,6 +320,8 @@ void parseargs(DSTATE *s, int argc, char
+ 			} else {
+ 				cfg.alwaysadd = 1;
+ 			}
++		} else if (strcmp(argv[currentarg], "--noexit") == 0) {
++			s->noexit = 1;
+ 		} else if (strcmp(argv[currentarg], "--initdb") == 0) {
+ 			s->initdb = 1;
+ 			s->showhelp = 0;