[Linux]Daily Health Check Script

제가 서버 상태를 체크하기 위해 실행하는 Shell Script입니다. “sysinfo.sh”을 crontab에 등록해서 메일 sysinfo.$(hostname).log를 생성시키고 있습니다. Postfix를 사용해서 이메일로 받아보고 있는데, Postfix 설정은 다음 Blog에서 소개시켜 드릴께요.

1. 아래 스크립트를 “sysinfo.sh” 파일에 저장합니다.

   #!/bin/bash
   
   # make seperators
   P=80
   S=$(printf '*%.s' {1..80})
   D=$(printf -- '-%.s' {1..80})
   
   function printTitleBox () {
   echo "$S"
   
   while [ $# -ne 0 ]
   do
   title=$1
   n=$((P / 2 - ${#title} / 2))
   m=$((P - n - ${#title}))
   
   printf "%-${n}s" "**"
   printf "$title"
   printf "%+${m}s\n" "**"
   shift
   done
   
   echo "$S"
   }
   
   # only print the header of output via pipeline
   function printHeaderOnly {
   IFS= read -r header
   printf '%s\n' "$header"
   echo "$D"
   "$@"
   }
   
   # get date
   NOW=$(date +"%Y-%m-%d")
   
   # create output file name
   OUTPUT=$(basename -s .sh $0)
   OUTPUT=$(dirname $0)"/${OUTPUT}.$(hostname).log"
   if ! [ -f $OUTPUT ]
   then
   touch $OUTPUT
   fi
   
   # Assign the fd 3 to $OUTPUT file
   exec 3> $OUTPUT
   
   printTitleBox "System Info for $(hostname) at ${NOW}" "(Updated by Archer of www.yesxyz.kr, 2023)" >&3
   
   echo "" >&3
   printTitleBox "Operating System Info" >&3
   hostnamectl >&3
   
   echo "" >&3
   printTitleBox "NTP and time configuration" >&3
   timedatectl >&3
   
   #uncomment if you run this script on a server for the first time
   #echo "" >&3
   #printTitleBox "Diplay information about the CPU architecture" >&3
   #lscpu | grep -i -v "flags" >&3
   
   echo "" >&3
   printTitleBox "Amount Of Free And Used Memory" >&3
   echo -e "CPU Usage:\t"`cat /proc/stat | awk '/cpu/{printf("%.2f%\n"), ($2+$4)*100/($2+$4+$5)}' | awk '{print $0}' | head -1` >&3
   avail=`cat /proc/meminfo | grep MemAvailable | awk '{print $2}'`
   total=`cat /proc/meminfo | grep MemTotal | awk '{print $2}'`
   usage=$((total - avail))
   echo -e "Memory Usage:\t"`echo "$usage $total" | awk '{printf("%.2f%"), $1/$2*100}'` >&3
   echo -e "Swap Usage:\t"`free | awk '/Swap/{printf("%.2f%"), $3/$2*100}'` >&3
   echo "$D" >&3
   lsmem | tail -3 >&3
   echo "$D" >&3
   free -h >&3
   #printf "%+${P}s\n" "(unit: mib)" >&3
   #vmstat -S m 3 5 >&3
   
   echo "" >&3
   printTitleBox "File System Disk Space Usage" >&3
   df -hT -x tmpfs -x devtmpfs -x iso9660 -x nfs | printHeaderOnly sort -nr -k 6 >&3
   echo "$D" >&3
   df -hT --total -x tmpfs -x devtmpfs -x iso9660 -x nfs | tail -1 >&3
   
   echo "" >&3
   printTitleBox "Top 5 Memory Eating Process" >&3
   ps -eo user,pid,ppid,%mem,%cpu,stat,start,time,comm --sort=-%mem | egrep -v top | head -6 >&3
   
   echo "" >&3
   printTitleBox "Top 5 CPU Eating Process" >&3
   ps -eo user,pid,ppid,%mem,%cpu,stat,start,time,comm --sort=-%cpu | egrep -v top | head -6 >&3
   
   echo "" >&3
   printTitleBox "Zombie Process Check" >&3
   top -bn 1 | grep zombie >&3
   ps -elf | grep defunct | grep -v grep >&3
   
   echo "" >&3
   printTitleBox "User Login History(Recent 5)" >&3
   last -5 -F >&3
   
   echo "" >&3
   printTitleBox "Users Failed to log in" >&3
   lastb -5 -F >&3
   
   echo "" >&3
   printTitleBox "Diagnostic Message" >&3
   dmesg -T -l emerg,alert,crit,err | tail -n 20 >&3
   
   echo "" >&3
   printTitleBox "Journal Database Log" >&3
   journalctl -p warning --since yesterday >&3
   
   exec 3>&-
   

2. chmod 755 sysinfo.sh 명령으로  실행권한을 부여합니다.
3. “sysinfo.sh” 파일을 실행시켜 “sysinfo.$(hostname).log” 파일이 생성되는 것을 확인합니다.
4. crontab -e 명령으로 cron에 등록해서 주기적으로 실행시키도록 합니다(매일 오전 7시 실행)

   [root@centos8 ~]# crontab -e
   0 7 * * * /path/sysinfo.sh