relay-cmd

   1 #!/bin/bash
   2
   3 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
   4
   5 usage() {
   6   cat <<EOF
   7 Usage: relay-cmd poweroff|poweron|reboot HOSTNAME|CHANNEL [RELAY_ID]
   8
   9 RELAY_ID is not needed if only 1 relay device is connected.  To
  10 understand CHANNEL and RELAY_ID, run hidusb-relay-cmd and
  11 hidusb-relay-cmd state.  I recommend writing a config in
  12 /etc/relay-cmd.conf , then using HOSTNAME instead of CHANNEL and
  13 RELAY_ID. It serves as documentation of what you connected the relay
  14 to. Example config:
  15
  16 # This config is just sourced from bash, so make sure its valid bash.
  17 # relay_id is not needed if only 1 relay is connected.
  18 cephserver3_channel=1
  19 cephserver3_relay_id=HURTM
  20 cephserver2_channel=2
  21 cephserver2_relay_id=HURTM
  22 EOF
  23   exit $1
  24 }
  25
  26
  27 if (( $# < 2 )); then
  28   usage
  29 fi
  30
  31 read action chan relay_id  <<<"$@"
  32
  33 if [[ -e /etc/relay-cmd.conf ]]; then
  34   source /etc/relay-cmd.conf
  35 fi
  36
  37 # we know HOSTNAME is given if it doesn't start with a number.
  38 if [[ $chan != [0-9]* ]]; then
  39   chan_var=${chan}_channel
  40   chan=${!chan_var}
  41   if [[ ! $chan ]]; then
  42     echo "error: channel not found in /etc/relay-cmd.conf" >&2
  43     exit 1
  44   fi
  45   if [[ ! $relay_id ]]; then
  46     relay_id_var=${chan}_relay_id
  47     relay=${!relay_id_var}
  48   fi
  49 fi
  50
  51
  52 if hidusb-relay-cmd state | grep ON; then
  53   printf "%s\n" "WARNING: output from hidusb-relay-cmd state shows an ON relay. this could mean another command instance is running, or it got stuck on due to an uncompleted command." >&2
  54 fi
  55
  56
  57 case $(hidusb-relay-cmd state|wc -l) in
  58   0)
  59     echo "error: got 0 lines from running hidusb-relay-cmd state" >&2
  60     exit 1
  61     ;;
  62   1) : ;;
  63   *)
  64     if [[ ! $relay_id ]]; then
  65       echo "error: more than 1 relay device, so passing its id is required" >&2
  66       exit 1
  67     fi
  68     ;;
  69 esac
  70
  71
  72 if [[ $relay_id ]]; then
  73   # leave this as an empty var if its not passed
  74   relay_id_arg="id=$relay_id"
  75 fi
  76
  77 # verbose command
  78 v() {
  79   printf "+ %s\n" "$*"
  80   "$@"
  81 }
  82
  83
  84 # ignore hup so we complete even if there is a connection problem.
  85 trap '' HUP
  86 echo "$0: doing $action. shell commands are printed to the terminal:"
  87 case $action in
  88   poweroff)
  89     v hidusb-relay-cmd $relay_id_arg on $chan
  90     v sleep 6
  91     v hidusb-relay-cmd $relay_id_arg off $chan
  92     ;;
  93   poweron)
  94     v hidusb-relay-cmd $relay_id_arg on $chan
  95     v sleep 1
  96     v hidusb-relay-cmd $relay_id_arg off $chan
  97     ;;
  98   reboot)
  99     v hidusb-relay-cmd $relay_id_arg on $chan
 100     v sleep 6
 101     v hidusb-relay-cmd $relay_id_arg off $chan
 102     v sleep 1
 103     v hidusb-relay-cmd $relay_id_arg on $chan
 104     v sleep 1
 105     v hidusb-relay-cmd $relay_id_arg off $chan
 106     ;;
 107   *)
 108     echo "error: action arg not supported" >&2
 109     exit 1
 110 esac
 111 echo "$0: script ended. exiting"