#! /bin/bash

########################
### System Variables ###
########################
if [ "$(command -v lsb_release)" ]; then
    OS=$(lsb_release -i | awk '{print $3}' | tr '[:upper:]' '[:lower:]')
    OSVER=$(lsb_release -r | awk '{print $2}' | awk -F. '{print $1}')
else 
    OS=$(grep PRETTY_NAME /etc/os-release | sed 's/PRETTY_NAME=//g' | tr -d '="' | awk '{print $1}' | tr '[:upper:]' '[:lower:]')
    OSVER=$(grep VERSION_ID /etc/os-release | sed 's/VERSION_ID=//g' | tr -d '="' | awk -F. '{print $1}')
fi

###########################################################
#### Detect Package Manger from OS and OSVer Variables ####
###########################################################
if [[ "${OS}" = amazon || "${OS}" = red ]]; then
        if [[ "${OSVER}" = 2 || "${OSVER}" = 7 ]]; then
                pkgmgr="yum -y"
        else
                pkgmgr="dnf -y"
        fi
elif [ "${OS}" = ubuntu ]; then
        pkgmgr="apt -y"
fi

#############################
#### Check for Directory ####
#############################
if [ ! -d "/var/lib/node_exporter/" ]; then
    mkdir -p /var/lib/node_exporter
    chown prometheus. /var/lib/node_exporter
fi

############################
#### Check for Cron Job ####
############################
if ! crontab -l | grep -q "cpu_usage.sh"; then
    echo -e "$(crontab -u root -l)\n*/3 * * * * /usr/local/bin/cpu_usage.sh > /var/lib/node_exporter/cpu_usage.prom 2>&1" | crontab -u root -
fi

if [ ! "$(command -v lsof)" ]; then
    $pkgmgr install lsof
fi

touch /usr/local/bin/cpu_usage.sh

{
    echo '#! /bin/bash'
    echo ''
    echo '########################################################'
    echo '###                                                  ###'
    echo '### Description: Expose metrics from cpu by process. ###'
    echo '###                                                  ###'
    echo '### Phil Connor pconnor@ara.com                      ###'
    echo '### Version 2.7.8.020524                             ###'
    echo '###                                                  ###'
    echo '########################################################'
    echo ''
    echo '#############################'
    echo '### Process List Function ###'
    echo '#############################'
    echo 'processes_list() {'
    echo '    {'
    # shellcheck disable=SC2016
    echo '        PList=$(ps aux)'
    echo ''
    echo '        while read -r PList'
    echo '        do'
    # shellcheck disable=SC2016
    echo '            pl=$(/usr/bin/awk '\''{print "node_cpu_usage{process=\""$11"\", pid=\""$2"\", owner=\""$1"\"}", $3}'\'')'
    # shellcheck disable=SC2016
    echo '        done <<< "$PList"'
    echo ''
    echo '        echo '\''# HELP node_cpu_usage Usage of CPU by process.'\'' '
    echo '        echo '\''# TYPE node_cpu_usage gauge'\'' ' 
    # shellcheck disable=SC2016
    echo '        echo "$pl"'
    echo '    }'
    echo '}'
    echo ''
    echo '##################################'
    echo '### File Handler List Function ###'
    echo '##################################'
    echo 'filehandlers_list() {'
    echo '    {'
    # shellcheck disable=SC2016,SC2028
    echo '        Fhlist=$(/usr/sbin/lsof | /usr/bin/awk '\''{gsub(/\\/,"",$1)}1 {gsub(/\\|\:/,"",$4)}1 {print $1 " " $2 " " $4}'\'' | sort | uniq -c | sort -rn | head -30)' 
    echo ''        
    echo '        while read -r Fhlist'
    echo '        do'
    # shellcheck disable=SC2016
    echo '            fhl=$(/usr/bin/awk '\''{print "node_file_handlers{pid=\""$1"\", program=\""$2"\"}", $3}'\'')'
    # shellcheck disable=SC2016
    echo '        done <<< "$Fhlist"'
    echo '        echo '\''# HELP node_file_handler Usage of File Handlers.'\'' '
    echo '        echo '\''# TYPE node_file_handler gauge'\'' '
    # shellcheck disable=SC2016
    echo '        echo "$fhl"'
    echo ''        
    # shellcheck disable=SC2016
    echo '        fhmax=$(cat /proc/sys/fs/file-nr | awk '\''{print $3}'\'')'
    # shellcheck disable=SC2016
    echo '        fhfree=$(cat /proc/sys/fs/file-nr | awk '\''{print $2}'\'')'
    # shellcheck disable=SC2016
    echo '        fhopen=$(cat /proc/sys/fs/file-nr | awk '\''{print $1}'\'')'
    echo '        echo '\''# HELP node_max_files Max File Limit Handlers.'\'' '
    echo '        echo '\''# TYPE node_max_files gauge'\'' '
    # shellcheck disable=SC2016
    echo '        echo "node_total_max_files_handles $fhmax"'
    # shellcheck disable=SC2016
    echo '        echo "node_total_free_file_handles $fhfree"'
    # shellcheck disable=SC2016
    echo '        echo "node_total_open_file_handles $fhopen"'
    echo ''
    echo '    }'
    echo '}'
    echo ''
    echo '################################'
    echo '### File Handler Connections ###'
    echo '################################'    
    echo 'filehandler_connections() {'
    echo '    {'
    # shellcheck disable=SC2016,SC2028
    echo '        fhconn=$(/usr/sbin/lsof -i | /usr/bin/awk '\''{gsub(/\\/,"_",$1)}1 {gsub(/\*|\:/"_",$2)}1 {gsub(/\*|\:|\\/,"",$9)}1'\'')'
    echo ''
    echo '        while read -r fhconn'
    echo '            do'
    # shellcheck disable=SC2016
    echo '                conn=$(/usr/bin/awk '\''NR>1 {print "node_file_handle_connection{command=\""$1"\", connection=\""$9"\", user=\""$3"\", protocol=\""$5"\", type=\""$8"\"}", $2}'\'')'
    # shellcheck disable=SC2016
    echo '            done <<< "$fhconn"'
    echo '        echo '\''# HELP node_file_handle_connection Connections by process.'\'' '
    echo '        echo '\''# TYPE node_file_handle_connection gauge'\'' '
    # shellcheck disable=SC2016
    echo '        echo "$conn"'
    echo '    }'
    echo '}'
    echo ''
    echo '######################'
    echo '### Function Calls ###'
    echo '######################'
    echo 'processes_list'
    echo 'filehandlers_list'
    echo 'filehandler_connections'
} > /usr/local/bin/cpu_usage.sh

chmod 755 /usr/local/bin/cpu_usage.sh


#################
### SEARCH="java"
### for i in $(ps -C "${SEARCH}" -o pid | grep -v PID); do        echo "PID # ${i} open files count : $(sudo ls -l /proc/${i}/fd | wc -l)"; done
###############

###############
### fuser -vm / 2>&1 | awk '$3 ~ /f|F/' | while read user pid flags rest; do printf '%10s %10s %10s %s\n' $user $pid $flags "$(</proc/$pid/cmdline)"; done
##############