Simple Bash Script that creates a monit config script from your PM2 Processes. Run using ./script.sh [-m YOUR_MONIT_DIR]

Monit Config Creator for PM2 - Better!

#!/bin/bash

# Some utility functions....
trailing_slash () {
    STR="${1}"
    length=${#STR}
    last_char=${STR:length-1:1}
    [[ $last_char != "/" ]] && STR="$monitDir/"; 

    echo $STR;
}
# To style messages for console
styled_echo () {

    case ${2} in
    red)
        text="\e[31m${1}\e[0m"
        ;;
    green)
        text="\e[32m${1}\e[0m"
        ;;
    blue)
        text="\e[34m${1}\e[0m"
        ;;
    yellow)
        text="\e[33m${1}\e[0m"
        ;;
    *)    # default color
        text="\e[39m${1}\e[0m"
        ;;
    esac

    echo -e $text
}


hasMonit=$(command -v monit)
hasJQ=$(command -v jq)

if ((${#hasMonit}==0))
then
    styled_echo "Hey! It doesn't look like monit is  installed! Get it here... https://mmonit.com/monit/" red
    exit 
fi

if ((${#hasJQ}==0))
then
    styled_echo "Hey! This script requires you to install JQ: https://stedolan.github.io/jq/" red
    exit 
fi

while [[ $# -gt 0 ]]
do
    # echo $#

    key="${1}"
    # echo $key

    case ${key} in
    -m|--monit)
        monitDir="${2}"
        ;;
    -h|--help)
        cat << EndOfMessage
Usage: ./pm2-make.sh [options]
Options are as follows:
	-c config     Path to the json configuration file
	-m monit      Path to the monit folder. (Often /etc/monit/)
EndOfMessage
        # shift # past argument
        shift
        ;;
    *)    # unknown option
        shift # past argument
        ;;
    esac
    shift

done

# Use Default Dir
monitDir=${monitDir:-"/etc/monit"}
# Ensure Trailing Slash
monitDir=$(trailing_slash  $monitDir )

# Ensure directory exists else
if [ ! -d "$monitDir" ]; then
  #No need to proceed, stop right here
  styled_echo "The monit folder entered '${monitDir}' does not exist!'" red
  exit 
fi

# Monit Folders
CONF_AVAILABLE_DIR="${monitDir}conf-available/" 
CONF_ENABLED_DIR="${monitDir}conf-enabled/" ;

styled_echo "NOTE: This script uses 'pm2 jlist' command to generate your monit script!"
printf '%*s\n' "${COLUMNS:-$(tput cols)}" '' | tr ' ' -

# Prepare monit config file
MONIT_FILE="${CONF_AVAILABLE_DIR}PM2";
# Drop File if exists
if [ -f $MONIT_FILE ] ; then
    styled_echo "Deleting old monit config file: ${MONIT_FILE}..." red
    rm $MONIT_FILE
fi

styled_echo "Writing monit config file: ${MONIT_FILE}..." blue
echo

# Loop through the processes
echo $(pm2 jlist)  | jq -cr ".[]" | while read o; do
    # Pick name & PID File...
    pid=$(echo $o | jq '.pid' | cut -d'"' -f 2)
    name=$(echo $o | jq '.name' | cut -d'"' -f 2)    
    status=$(echo $o | jq '.pm2_env.status' | cut -d'"' -f 2)
    pid_file=$(echo $o | jq '.pm2_env.pm_pid_path' | cut -d'"' -f 2)

    # echo "${status}";
    if [ "${status}" == "online" ]
    then
        styled_echo "Adding monit config for process '${name}' - [status=${status}]" yellow
        # make monit config command & write to file
        monitCMD="check process PM2-${name} with pidfile '$pid_file'"    
        echo $monitCMD $'\n' >> $MONIT_FILE 
    else
        styled_echo "Skipping monit config for process '${name}' - [status=${status}]" red
    fi

done

printf '%*s\n' "${COLUMNS:-$(tput cols)}" '' | tr ' ' - 
# create symbolic link...
styled_echo "Enabling monit config file ${MONIT_FILE} i.e (symbolic link to ${CONF_ENABLED_DIR})" blue

# Check that symbolink link points to the right file in /conf-available
if [[ -L "${CONF_ENABLED_DIR}PM2" && -f "${CONF_AVAILABLE_DIR}PM2" ]]
then
    # All good!
    styled_echo "Symbolic link exists!" green
else
    if [ -f "${CONF_ENABLED_DIR}PM2" ]        
    then
        # Symbolic link does not point to the right file or is broken, replace
        styled_echo "Replacing symbolic link..." red
        ln -sf $MONIT_FILE $CONF_ENABLED_DIR
    else
        # Symbolic link does not exist. Create
        styled_echo "Creating new symbolic link..." yellow
        ln -s $MONIT_FILE $CONF_ENABLED_DIR
    fi

fi

printf '%*s\n' "${COLUMNS:-$(tput cols)}" '' | tr ' ' -
# Reload Monit
styled_echo "Reloading Monit" blue
monit reload
styled_echo "All Ready!" green

Sample Monit Daemon

#!/bin/bash

#Where
#watchScript=/usr/local/bin/watchfile.sh
#pm2MonitScript=/usr/local/bin/pm2-monit.sh

#command
bash /usr/local/bin/watchfile.sh \ 
      -s "find PM2_HOME/pids/ -type f -print0 | xargs -0 stat" \
      -e /usr/local/bin/pm2-monit.sh > /dev/null &

You can automate this script by using a utility such as watchfile to run whenever PM2 pids change.

./watchfile.sh -s "find /PM2_HOME/pids/ -type f -print0 | xargs -0 stat" -e /PATH_TO_YOUR_SCRIPT/script.sh

See: https://stackoverflow.com/a/25404832