From d2b5d6a9419272bb521bd2a80af863fe0e16805a Mon Sep 17 00:00:00 2001
From: Ian Kelling <iank@fsf.org>
Date: Mon, 4 Mar 2019 10:42:27 -0500
Subject: [PATCH] make relay-cmd have config to replace libremanage

---
 README    | 12 ++++---
 relay-cmd | 94 ++++++++++++++++++++++++++++++++++++++++++-------------
 2 files changed, 79 insertions(+), 27 deletions(-)

diff --git a/README b/README
index ed10daf..01be120 100644
--- a/README
+++ b/README
@@ -1,11 +1,13 @@
-Run hidusb-relay-cmd-setup.
+First, run hidusb-relay-cmd-setup on the device its connected to.  Ian
+Kelling also has a package for openwrt, not yet published.  Ask him if
+you are interested.
 
-relay-cmd is a very simple command to use the relay.
+relay-cmd is a simple script config to use the relay from the device its
+connected to. NOT YET TESTED.
 
-libremanage is an overly complicated command. It requires a
-configuration. See the USAGE which will pop up if you make a mistake!
+libremanage is an overly complicated command that is deprecated. Some
+problems with it:
 
-TODO
 * IMPORTANT: libremanage right now does ssh relay command 1; sleep; ssh
   relay command 2. That whole thing needs to be made into a local script
   or else if the second ssh command fails, the relay stays in the state
diff --git a/relay-cmd b/relay-cmd
index 982e460..6ed7eae 100755
--- a/relay-cmd
+++ b/relay-cmd
@@ -1,13 +1,52 @@
 #!/bin/bash
 
-# usage: relay-cmd poweroff|poweron|reboot chan [relay_id]
-# relay_id not required if there is only one relay.
+trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
+
+usage() {
+  cat <<EOF
+Usage: relay-cmd poweroff|poweron|reboot HOSTNAME|CHANNEL [RELAY_ID]
+
+For CHANNEL and RELAY_ID, run hidusb-relay-cmd and hidusb-relay-cmd state.
+I recommend writing a config to use HOSTNAME instead. Config is /etc/relay-cmd.conf
+Example config:
+
+# This config is just bash that gets sourced.
+# relay_id is not needed if only 1 relay is connected.
+cephserver3_channel=1
+cephserver3_relay_id=HURTM
+EOF
+  exit $1
+}
+
+
+if (( $# < 2 )); then
+  usage
+fi
+
+read action chan relay_id  <<<"$@"
+
+if [[ -e /etc/relay-cmd.conf ]]; then
+  source /etc/relay-cmd.conf
+fi
+
+if [[ $chan != [0-9]* ]]; then
+  chan_var=${chan}_channel
+  chan=${!chan_var}
+  if [[ ! $chan ]]; then
+    echo "error: channel not found in /etc/relay-cmd.conf" >&2
+    exit 1
+  fi
+  if [[ ! $relay_id ]]; then
+    relay_id_var=${chan}_relay_id
+    relay=${!relay_id_var}
+  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
 fi
 
-read action chan relay_id  <<<"$@"
 
 case $(hidusb-relay-cmd state|wc -l) in
   0)
@@ -15,41 +54,52 @@ case $(hidusb-relay-cmd state|wc -l) in
     exit 1
     ;;
   1) : ;;
-  *) if [[ ! $relay_id ]]; then
-       echo "error: more than 1 relay device, so passing its id is required" >&2
-       exit 1
-     fi
-     ;;
+  *)
+    if [[ ! $relay_id ]]; then
+      echo "error: more than 1 relay device, so passing its id is required" >&2
+      exit 1
+    fi
+    ;;
 esac
 
+
 if [[ $relay_id ]]; then
   # leave this as an empty var if its not passed
   relay_id_arg="id=$relay_id"
 fi
 
-# ignore hup so we complete
+# verbose command
+v() {
+  printf "+ %s\n" "$*"
+  "$@"
+}
+
+
+# ignore hup so we complete even if there is a connection problem.
 trap '' HUP
+echo "$0: doing $action. shell commands are printed to the terminal:"
 case $action in
   poweroff)
-    hidusb-relay-cmd $relay_id_arg on $chan
-    sleep 6
-    hidusb-relay-cmd $relay_id_arg off $chan
+    v hidusb-relay-cmd $relay_id_arg on $chan
+    v sleep 6
+    v hidusb-relay-cmd $relay_id_arg off $chan
     ;;
   poweron)
-    hidusb-relay-cmd $relay_id_arg on $chan
-    sleep 1
-    hidusb-relay-cmd $relay_id_arg off $chan
+    v hidusb-relay-cmd $relay_id_arg on $chan
+    v sleep 1
+    v hidusb-relay-cmd $relay_id_arg off $chan
     ;;
   reboot)
-    hidusb-relay-cmd $relay_id_arg on $chan
-    sleep 6
-    hidusb-relay-cmd $relay_id_arg off $chan
-    sleep 1
-    hidusb-relay-cmd $relay_id_arg on $chan
-    sleep 1
-    hidusb-relay-cmd $relay_id_arg off $chan
+    v hidusb-relay-cmd $relay_id_arg on $chan
+    v sleep 6
+    v hidusb-relay-cmd $relay_id_arg off $chan
+    v sleep 1
+    v hidusb-relay-cmd $relay_id_arg on $chan
+    v sleep 1
+    v hidusb-relay-cmd $relay_id_arg off $chan
     ;;
   *)
     echo "error: action arg not supported" >&2
     exit 1
 esac
+echo "$0: script ended. exiting"
-- 
2.25.1