After using the simple watchdog for a while I needed to monitor another network interface. Since the old script couldn’t be extended nicely (without creating lots of redundant code), I decided to rewrite the whole thing! This new version allows me to set up multiple watchdogs with custom commands within the configuration file. See how you can use it too:
Configuration
First create a new configuration file /etc/config/watchping:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 |
config watchping 'wifi' option enabled '1' option host 'wifi.accesspoint' option timeout '3' option command '/sbin/wifi' # "If wifi is already up when you run "wifi" with no parameters, the wifi system will be stopped and restarted." config watchping 'network' option enabled '0' option host 'network.uplink' option timeout '3' option command '/etc/init.d/network restart' config watchping 'openvpn' option enabled '1' option host 'my.vpn.server' option timeout '5' option command '/etc/init.d/openvpn restart' |
This configures watchping with three instances. Each instance will ping the specified host and issue the restart command after the timeout expires. Customize this file to your needs, e.g. add your own hosts or disable instances you don’t need.
The scripts
Next create the folder /usr/lib/watchping/ and upload the following script:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 |
#!/bin/sh # # Pings a remote host and restarts WiFi/OpenVPN if the connection is down # Requires "fping" -> opkg install fping # # Copyright (C) 2020 luani.de . /lib/functions.sh # check prerequisites if [ ! -x "$(command -v fping)" ]; then echo 'watchping error: fping is not installed, exiting' >&2 exit 1 fi config_load watchping if [ $? -ne 0 ]; then echo 'watchping error: configuration not found, exiting' >&2 exit 1 fi # setup function, parse config & check ranges setup_check() { local job=$1 if [ -z $job ]; then return 1; fi local enabled config_get_bool enabled ${job} enabled "false" if [ "$enabled" -eq "1" ]; then local host local timeout local command config_get host ${job} host "localhost" config_get timeout ${job} timeout "5" config_get command ${job} command "" if [ $timeout -le 0 ]; then $timeout=5 fi if [ -z "$command" ]; then return 1 fi eval "${job}_host"=\$host eval "${job}_timeout"=\$timeout eval "${job}_command"=\$command eval "${job}_failcount"=0 joblist="${joblist} ${job}" logger -t "watchping" "job '${job}' setup: host '${host}', timeout ${timeout} min" fi } # check function perform_check() { local job=$1 local host local timeout local command local failcount local failure=0 eval host=\$"${job}_host" eval timeout=\$"${job}_timeout" eval command=\$"${job}_command" eval failcount=\$"${job}_failcount" # ping host fping --ipv4 --quiet --count 1 --random ${host} &> /dev/null if [ $? -ne 0 ]; then failure=1 let "failcount++" else failcount=0 fi if [ $failcount -ge $timeout ]; then failcount=0 logger -t "watchping" "job '${job}' failure: host (${host}) is down for $timeout min, command initiated!" # restart service eval "$command" fi eval "${job}_failcount"=\$failcount return $failure } # read configuration joblist="" config_foreach setup_check watchping # check loop firstrun=true while sleep 60; do for job in $joblist; do perform_check ${job} if [ $? -eq 0 ] && [ "$firstrun" = true ]; then logger -t "watchping" "job '${job}' first run: executed successfully, host reachable" elif [ "$firstrun" = true ]; then logger -t "watchping" "job '${job}' first run: failed, host unavailable" fi done if [ "$firstrun" = true ]; then firstrun=false; fi done exit 0 |
Finally upload the init script to /etc/init.d/watchping:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 |
#!/bin/sh /etc/rc.common # # start watchdog # # https://openwrt.org/docs/guide-developer/procd-init-script-example # Copyright (C) 2020 luani.de # Init sequence START=99 STOP=10 # PROCD USE_PROCD=1 start_service() { procd_open_instance watchping procd_set_param command /bin/sh "/usr/lib/watchping/watchping.sh" procd_set_param respawn ${respawn_threshold:-3600} ${respawn_timeout:-5} ${respawn_retry:-5} procd_set_param stdout 1 # forward stdout of the command to logd procd_set_param stderr 1 # same for stderr procd_set_param pidfile /var/run/watchping.pid procd_close_instance } stop_service() { logger -t "watchping" "watchdog stopped!" } service_triggers() { procd_add_reload_trigger "watchping" } reload_service() { stop start } |
Final touches
The watchping script requires fping to be installed on the router:
|
1 2 3 4 5 6 7 8 9 10 11 12 |
# install dependencies opkg update opkg install fping # make executable chmod +x /usr/lib/watchping/watchping.sh chmod +x /etc/init.d/watchping # enable & start service # you can also do this from LuCI, system -> startup /etc/init.d/watchping enable /etc/init.d/watchping start |
Check your system log and verify the watchdog started correctly:
|
1 2 |
user.notice watchping: job 'wifi' setup: host 'wifi.accesspoin', timeout 3 min user.notice watchping: job 'wifi' first run: executed successfully, host reachable |
Tested with OpenWRT 19.07
Pingback:OpenWRT: FRITZ!Box reboot/reconnect script – LUANI
I have a question:
What do I have to enter in the config if I want to ping 192.168.0.4?
Hi, you can specify an IP as the host address:
config …
option host ‚192.168.0.4‘