CODEWITHSUNDEEP
bashshellcron
Ariane Martins Gomes Do Rego
Ariane Martins Gomes Do Rego

Reputation: 155

A shell script that checks if the nginx service is running, with action

#!/bin/bash
date=$(date +"%Y-%m-%d %H:%M:%S")
getpid=$(pgrep nginx | wc -l 
if [ "$getpid" > 0 ]
then
  echo 'Nginx is Fine, It is Running at' $date
else
  echo "Error on Nginx and stoped at" $date
  sudo fuser -k 443/tcp
  sudo service nginx start
  sudo service  monit start
  sudo monit monitor all
  echo "Error on Nginx and stoped at" $date | mailx -s "The Nginx Stop - But it is Fixed" -A /root/nginx_log3.txt mymail.com
fi
exit 0;

I see several ways to check the service:

$(ps ax | grep myName | fgrep -v grep | awk '{ print $1 }')

or

if (( $(ps -ef | grep -v grep | grep $service | wc -l) > 0 ))

and several ways...

innumerable means of checking if a process is running, but the problem, is that even though I terminate nginx, any command using PS always brings many results with pid values! since pgrep always shows 0 after I do service nginx stop, and the gprep seems perfect to compare with value 0 which is less than any pid,

because if it has run, always show pid above velor 0, pgrep is the path , but the problem is that I have a crontab that runs this script every 3 minutes, and even with the process running, with a pid greater than zero, it is restarting the service!

I found several blogs teaching several scripts for this, but none works!

I have the monit to keep the services alive, but sometimes it fails.

clearly I am not sure how to compare the values, of the extracted pid with the value 0:

getpid=$(pgrep nginx | wc -l)
    if [ "$getpid" > 0 ]

because the service is always restarting every 3 minutes, even the service running with a pid running (value greater than 0)

I really appreciate your help!

Upvotes: 0

Views: 3404

Answers (1)

Mike Q
Mike Q

Reputation: 7327

I would maybe check the www services that you are trying to serve instead of if the service is running. Take a look at these various examples :

    https=$(nc -z localhost 443)
    http=$(nc -z localhost 80)
    netstt_cnt=$(netstat -ntlp | grep httpd | wc -l)

    http_issues=""
    if [[ ! $https ]] || [[ ! $http ]] ;then
        http_issues=" -Http/https ports not detected "
    fi
    if [ $netstt_cnt -ne 2 ] ;then
        http_issues="${http_issues} -Netstat not reporting httpd "
    fi

    # -- if http_host_check is set perform httpd checks
    local code_stat=""
    if [[ $http_host_check ]] ;then
        http_code=$(curl --write-out %{http_code} --silent --output /dev/null $http_host_check)
        if [ $http_code -lt 1 ] ;then
            http_issues="${http_issues} -Apache NOT serving pages http_code=$http_code. "
        elif [ $http_code -gt 399 ] ;then
            http_issues="${http_issues} -Apache Error http_code=$http_code on test page ${http_host_check}. "
        fi
        code_stat=", (http_code=${http_code}) "
    fi

    # -- php FPM sock, see readonly var $PHP_FPM_SOCK for use set to "" to disable this check.
    if [[ $PHP_FPM_SOCK ]] ;then
        if ! echo /dev/null | socat UNIX:${PHP_FPM_SOCK} - ;then
            http_issues="${http_issues} -php-fpm sock not communicating"
        fi
    fi

    if [[ $http_issues ]] ;then
            echo "Error on Nginx and stoped at" $date
            sudo service nginx stop
            sudo service  monit stop
            sudo fuser -k 443/tcp
            sleep 10    
            sudo service nginx start
            sudo service  monit start
            sudo monit monitor all
            if [[ $http_host_check ]] ;then
                http_code=$(curl --write-out %{http_code} --silent --output /dev/null $http_host_check)
             if [ $http_code -lt 1 ] ;then
                http_issues="${http_issues} -Apache NOT serving pages http_code=$http_code. "
            elif [ $http_code -gt 399 ] ;then
                http_issues="${http_issues} -Apache Error http_code=$http_code on test page ${http_host_check}. "
            fi
            sleep 5
            code_stat=", (http_code=${http_code}) "
            echo "Webserver had a problem, current status is $code_stat" $date | mailx -s "The Nginx stop: $code_stat" -A /root/nginx_log3.txt mymail.com  
    fi

    echo "Current Status : $http_issues"

Update: super simple example added here :

http_code=$(curl --write-out %{http_code} --silent --output /dev/null http://my_domain.com/)
    if [ $http_code -lt 1 ] ;then
        echo "${http_issues} -Apache NOT serving pages http_code=$http_code. "
        // ... do something here (restart web server)..
    fi

Upvotes: 2

Related Questions