Run node server on boot

Question

I am trying to run a node app on boot. The script runs ok from the command line, I can stop and start it but when I try to do it on boot I get an error as if the script were reading the node_app.js line by line.

Here is my script my_node_server:

#! /bin/bash

### BEGIN INIT INFO
# Provides:          skeleton
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Example initscript
# Description:       This file should be used to construct scripts to be
#                    placed in /etc/init.d.
### END INIT INFO


# Some things that run always

APP_DIR="/home/pi/node_app_folder"

NODE_APP="node_app.js"

LOG_FILE="/home/pi/my_node_server.log"

PID_FILE="/home/pi/my_node_server.pid"

NODE_EXEC=$(which node)


# Carry out specific functions when asked to by the system
case "$1" in
  start)
    echo "Starting script my_node_server "
    echo "Check log in /home/pi/my_node_server.log"

    echo "" > "$LOG_FILE"
    echo "" > "$PID_FILE"

    "$NODE_EXEC" "$APP_DIR/$NODE_APP" > "$LOG_FILE" 2>&1 &

    echo $! > "$PID_FILE"
    echo  "my_node_server is working with pid: $(cat $PID_FILE)" | tee "$LOG_FILE"
    echo "Check pid in /home/pi/my_node_server.pid"
    ;;
  stop)
    echo "Stopping script my_node_server" | tee -a "$LOG_FILE"
    PID="$(cat "$PID_FILE")"
    echo killing PID: "$PID"
    kill "$PID"
    ;;
  *)
    echo "Usage: /etc/init.d/my_node_server {start|stop}"
    exit 1
    ;;
esac

exit 0

It also works on the command line, from both pi and root users:

APP_DIR="/home/pi/node_app_folder"

NODE_APP="node_app.js"

NODE_PROGRAM=$(which node)

"$NODE_PROGRAM" "$APP_DIR/$NODE_APP" 2>&1

Why does it not do it at boot time? I have done:

sudo update-rc.d my_node_server defaults

By the way my shell is bash:

$ echo $0
/bin/bash

If I replace

"$NODE_EXEC" "$APP_DIR/$NODE_APP" > "$LOG_FILE" 2>&1 &

for

/home/pi/my-node-dir/bin/node /home/pi/node_app.js > "$LOG_FILE" 2>&1 &

it works ok.

So, what am I missing?

Answer 1

You could confirm this by logging the value of $NODE_EXEC somewhere, but I think it is probably not what you think it is.

NODE_EXEC=$(which node)

It certainly won't be /home/pi/my-node-dir/bin/node, because that path isn't in $PATH. If there's a node in $PATH, it would use that. If there isn't, that variable will be "which: no node in (...)".

You could add to path at beginning:

PATH=$PATH:/home/pi/my-node-dir/bin

Or you could just hardcode $NODE_EXEC to the value you actually want.