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[libremanage.git] / libremanage

#!/bin/bash

trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
set -eE -o pipefail

# verbose command
v() {
  printf "$0 running: %s\n" "$*"
  "$@"
}


usage() {
  cat <<EOF
Usage: libremanage poweroff|poweron|reboot HOSTNAME|CHANNEL [BOARD_ID]

HOSTNAME is based on configuration in /etc/libremanage.conf.

Note, the relay's channels default state when plugged in are off.

Example config:

# This config is sourced from bash, so make sure its valid bash.
cephserver3_channel=1
cephserver3_board_id=HURTM
cephserver2_channel=2
cephserver2_board_id=HURTM
# end of config

Example usage given the above config:

libremanage reboot cephserver3

BOARD_ID is not needed if only 1 relay device is connected, or if it is
defined in the config. To understand CHANNEL and BOARD_ID, run
hidusb-relay-cmd and hidusb-relay-cmd state.


WARNING: Avoid ever manually running "hidusb-relay-cmd on" in
production, because if you lose connectivity and can't turn it off, its
like the server's power button is stuck being pushed in and it won't
turn on in that state. You will need to physically replug usb power to
the relay so the channel goes back to its default off state. If this
script somehow dies after turning a relay on, running it again will turn
it off. That is why this script runs locally and ignores signals when
its running. If you run this script over ssh and lose connection as this
script is running, it will continue to run and complete.

EOF
  if [[ -e /etc/libremanage.conf ]]; then
    echo "Current config:"
    cat /etc/libremanage.conf
  else
    echo "Note: /etc/libremanage.conf does not exist on the current machine"
  fi
  exit 0
}


if (( $# < 2 )); then
  usage
fi

read action chan board_id  <<<"$@"

if [[ -e /etc/libremanage.conf ]]; then
  source /etc/libremanage.conf
fi

# Use config vars when appropriate. We know the arg is a HOSTNAME if it
# doesn't start with a number.
if [[ $chan != [0-9]* ]]; then
  if [[ ! $board_id ]]; then
    board_id_var=${chan}_board_id
    board_id=${!board_id_var}
  fi
  chan_var=${chan}_channel
  chan=${!chan_var}

  if [[ ! $chan ]]; then
    echo "error: channel not found in /etc/libremanage.conf" >&2
    exit 1
  fi
fi


if hidusb-relay-cmd state | grep ON; then
  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
  # TODO: exit in this case and print out the command to turn it off.
fi


case $(hidusb-relay-cmd state|wc -l) in
  0)
    echo "error: got 0 lines from running hidusb-relay-cmd state" >&2
    exit 1
    ;;
  1) : ;;
  *)
    if [[ ! $board_id ]]; then
      echo "error: more than 1 relay device, so passing its id is required" >&2
      exit 1
    fi
    ;;
esac


if [[ $board_id ]]; then
  # leave this as an empty var if its not passed
  board_id_arg="id=$board_id"
fi

# ignore errors and continue on if a command fails from here
set +eE +o pipefail
# ignore hup so we complete even if there is a connection problem, and
# force anyone to kill -9 so we might complete in more cases, for
# example if a reboot is happening
trap '' HUP INT QUIT TERM
echo "$0: doing $action. shell commands will be printed to the terminal."
case $action in
  poweroff)
    v hidusb-relay-cmd $board_id_arg on $chan
    v sleep 6
    v hidusb-relay-cmd $board_id_arg off $chan
    ;;
  poweron)
    v hidusb-relay-cmd $board_id_arg on $chan
    v sleep 1
    v hidusb-relay-cmd $board_id_arg off $chan
    ;;
  reboot)
    v hidusb-relay-cmd $board_id_arg on $chan
    v sleep 6
    v hidusb-relay-cmd $board_id_arg off $chan
    v sleep 1
    v hidusb-relay-cmd $board_id_arg on $chan
    v sleep 1
    v hidusb-relay-cmd $board_id_arg off $chan
    ;;
  *)
    echo "error: action arg not supported" >&2
    exit 1
esac
echo "$0: script ended. exiting"