gpsd: add wrapper script for hotplug/respawn handling

utils/gpsd/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=gpsd
 PKG_VERSION:=3.26.1
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=@SAVANNAH/$(PKG_NAME)
@@ -141,6 +141,7 @@ define Package/gpsd/install
 	$(INSTALL_BIN) ./files/gpsd.init $(1)/etc/init.d/gpsd
 	$(INSTALL_DIR) $(1)/usr/sbin
 	$(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/sbin/gpsd $(1)/usr/sbin/
+	$(INSTALL_BIN) ./files/usr/sbin/gpsd-wrapper $(1)/usr/sbin/
 
 	$(INSTALL_DIR) $(1)/etc/gpsd
 	$(INSTALL_BIN) ./files/etc/gpsd/device-hook $(1)/etc/gpsd/

utils/gpsd/files/gpsd.init

@@ -3,8 +3,9 @@
 START=50
 
 USE_PROCD=1
-PROG=/usr/sbin/gpsd
+PROG=/usr/sbin/gpsd-wrapper
 NAME=gpsd
+SOCKET=/var/run/gpsd.sock
 
 LOG_LEVEL="0"
 
@@ -36,7 +37,7 @@ gpsd_instance()
 	procd_append_param command -S "$port"
 	procd_append_param command -D "$LOG_LEVEL"
 	[ "$readonly" = "1" ] && procd_append_param command -b
-	procd_append_param command -F /var/run/gpsd.sock
+	procd_append_param command -F "$SOCKET"
 	for device in $devices; do
 		procd_append_param command "$device"
 	done
@@ -55,12 +56,3 @@ service_triggers() {
 	procd_add_reload_trigger "$NAME"
 	procd_add_validation validate_section_gpsd
 }
-
-service_started() {
-	local enabled
-
-	enabled="$(uci_get gpsd core enabled 0)"
-	[ "$enabled" = "0" ] && return
-
-	env -i ACTION="STARTED" /sbin/hotplug-call gpsd
-}

utils/gpsd/files/usr/sbin/gpsd-wrapper

@@ -0,0 +1,46 @@
+#!/bin/sh
+
+SOCKET="/var/run/gpsd.sock"
+
+trap_with_arg() {
+	func="$1" ; shift
+	for sig; do
+		# shellcheck disable=SC2064
+		trap "$func $sig" "$sig"
+	done
+}
+
+func_trap() {
+	logger -t "gpsd-wrapper[$$]" "Sending signal ${1}..."
+	kill "-${1}" "$CHILD" 2>/dev/null
+}
+
+wait_for_socket_and_hotplug() {
+	local count=0
+	while [ $count -lt 15 ]; do
+		[ -S "$SOCKET" ] && break
+		sleep 1
+		count=$((count + 1))
+	done
+
+	if [ -S "$SOCKET" ]; then
+		logger -t "gpsd-wrapper[$$]" "Socket ready, sending hotplug call"
+		env -i ACTION="STARTED" /sbin/hotplug-call gpsd
+	else
+		logger -t "gpsd-wrapper[$$]" \
+			"Socket $SOCKET not ready after ${count}s, hotplug skipped"
+	fi
+}
+
+main() {
+	trap_with_arg func_trap INT TERM KILL
+
+	/usr/sbin/gpsd "$@" &
+	CHILD="$!"
+
+	wait_for_socket_and_hotplug
+
+	wait "$CHILD"
+}
+
+main "$@"