nut: comment and simplify server script

Attempt to de-mystify the nut-server initscript by adding comments
and factoring out some common code that adds to complexity of the
functions of which it is part.

Signed-off-by: Daniel F. Dickinson <redacted>

diff --git a/net/nut/files/nut-server.init b/net/nut/files/nut-server.init
index 52c001edbd97f9dac767fbe281e2127047c7f930..caa0a2398db2472a007085cc4947db25d5d13697 100755 (executable)
--- a/net/nut/files/nut-server.init
+++ b/net/nut/files/nut-server.init
@@ -410,6 +410,24 @@ list_running_instances() {
        fi
 }
 
+signal_instance() {
+       local instance_name="$1"
+       local process_name="$2"
+       local signal_command="$3"
+       local signal="$4"
+       local pidfile="$5"
+       local secondary_command="$6"
+
+       if [ -s "$pidfile" ]; then
+               $signal_command | logger -t nut-server
+       elif pgrep "$process_name" >/dev/null 2>/dev/null; then
+               procd_send_signal nut-server "$instance_name" "$signal" 2>&1 | logger -t nut-server
+       fi
+       if [ -n "$secondary_command" ] && procd_running "$instance_name"; then
+               $secondary_command 2>&1 | logger -t nut-server
+       fi
+}
+
 stop_ups_driver() {
        local ups="$1" # The ups (driver instance)
        local requested="$2"
@@ -423,6 +441,7 @@ stop_ups_driver() {
        srv_statepath
        build_ups_config "$ups"
 
+       # If we don't have UPS configuration simply stop all instances
        if [ "$haveupscfg" != "1" ]; then
                if procd_running nut-server '*' >/dev/null 2>&1; then
                        procd_kill nut-server '*' 2>&1 | logger -t nut-server
@@ -433,13 +452,9 @@ stop_ups_driver() {
        config_get driver "$ups" driver "usbhid-ups"
 
        if procd_running nut-server "$ups"; then
-               if [ -s "${STATEPATH}/${driver}-${ups}".pid ]; then
-                       /lib/nut/"${driver}" -c exit -a "${ups}" 2>&1 | logger -t nut-server
-               elif pgrep "${driver}" >/dev/null 2>/dev/null; then
-                       procd_send_signal nut-server "${driver}" TERM 2>&1 | logger -t nut-server
-               fi
+               signal_instance "$ups" "$driver" "/lib/nut/'${driver}' -c exit -a '${ups}'" "TERM" "${STATEPATH}/${driver}-${ups}.pid"
                if procd_running nut-server upsd >/dev/null 2>&1; then
-                       procd_kill nut-server upsd 2>&1 | logger -t nut-server
+                       signal_instance upsd upsd "upsd -c stop" "TERM" "${STATEPATH}/upsd.pid" "procd_kill upsd"
                fi
        fi
 }
@@ -467,12 +482,7 @@ reload_ups_driver() {
 
        # Try to reload, otherwise exit politely, then stop and restart procd instance
        if procd_running nut-server "$ups"; then
-               if [ -s "${STATEPATH}/${driver}-${ups}".pid ]; then
-                       # should be respawned by procd
-                       /lib/nut/"${driver}" -c reload-or-exit -a "${ups}" 2>&1 | logger -t nut-server
-               elif pgrep "${driver}" >/dev/null 2>/dev/null; then
-                       procd_send_signal nut-server "${driver}" TERM 2>&1 | logger -t nut-server
-               fi
+               signal_instance "$ups" "$driver" "/lib/nut/'${driver}' -c reload-or-exit -a '${ups}'" HUP "${STATEPATH}/${driver}-${ups}.pid"
        fi
        /etc/init.d/nut-server start "$ups" 2>&1 | logger -t nut-server
 }
@@ -512,23 +522,25 @@ reload_service() {
                done
        fi
 
+       # If nut-server was started but has no instances (even upsd)
        if server_active; then
                logger -t nut-server "nut-server active with no instances"
                /etc/init.d/nut-server start 2>&1 | logger -t nut-server
+       # Otherwise, if we have at least one instance running
        elif procd_running nut-server; then
+               # If server (upsd) is running
                if procd_running nut-server upsd; then
                        # Try to signal server (upsd) to reload configuration
-                       if [ -s "${STATEPATH}/upsd.pid" ]; then
-                               upsd -c reload 2>&1 | logger -t nut-server
-                       elif pgrep upsd >/dev/null 2>/dev/null; then
-                               procd_send_signal nut-server upsd HUP 2>&1 | logger -t nut-server
-                       fi
+                       signal_instance "upsd" "upsd" "upsd -c reload" HUP "${STATEPATH}/upsd.pid"
+               # If server (upsd) is not running
                else
+                       # Start server (upsd)
                        /etc/init.d/nut-server start "upsd" 2>&1 | logger -t nut-server
                fi
                config_foreach reload_ups_driver driver
 
                # Stop any driver instances which are no longer configured
+               # We can only reliably do this for instances managed by procd
                for instance in $(list_running_instances "nut-server"|sed -e 's/upsd//'); do
                        unset driver
                        config_get driver "$instance" driver
@@ -536,6 +548,7 @@ reload_service() {
                                procd_kill nut-server "$instance" 2>&1 | logger -t nut-server
                        fi
                done
+       # Nut-server is not started, so start it
        else
                /etc/init.d/nut-server start 2>&1 | logger -t nut-server
        fi
@@ -547,21 +560,13 @@ stop_service() {
 
        case $@ in
        "")
+               # If nut-server was started but has no instances (even upsd)
                if server_active; then
                        logger -t nut-server "nut-server active with no instances"
                        procd_kill nut-server 2>&1 | logger -t nut-server
                elif procd_running nut-server; then # if have at least one instance
-                       if procd_running nut-server upsd; then
-                               # Try to exit politely, then stop procd instance
-                               if [ -s "${STATEPATH}/upsd.pid" ]; then
-                                       upsd -c stop 2>&1 | logger -t nut-server
-                               elif pgrep upsd >/dev/null 2>/dev/null; then
-                                       procd_send_signal nut-server upsd TERM 2>&1 | logger -t nut-server
-                               fi
-                               if procd_running nut-server upsd >/dev/null 2>&1; then
-                                       procd_kill nut-server upsd 2>&1 | logger -t nut-server
-                               fi
-                       fi
+                       signal_instance "upsd" "upsd" "upsd -c stop" TERM "${STATEPATH}/upsd.pid" "procd_kill nut-server upsd"
+
                        config_foreach stop_ups_driver driver
 
                        # Also stop any driver instances which are no longer configured
@@ -571,6 +576,7 @@ stop_service() {
                                fi
                        done
 
+                       # If nut-server active but has no instances (even upsd)
                        if server_active >/dev/null 2>&1; then
                                procd_kill nut-server 2>&1 | logger -t nut-server
                        fi
@@ -578,12 +584,8 @@ stop_service() {
                ;;
        *upsd*)
                if procd_running nut-server upsd; then
-                       # Try to exit politely, then stop procd instance
-                       if [ -s "${STATEPATH}/upsd.pid" ]; then
-                               upsd -c stop 2>&1 | logger -t nut-server
-                       elif pgrep upsd >/dev/null 2>/dev/null; then
-                               procd_send_signal nut-server upsd TERM 2>&1 | logger -t nut-server
-                       fi
+                       signal_instance "upsd" "upsd" "upsd -c stop" TERM "${STATEPATH}/upsd.pid" "procd_kill nut-server upsd"
+                       # If nut-server is active with no instances
                        if server_active; then
                                procd_kill nut-server 2>&1 | logger -t nut-server
                        fi