The Server Health Check

Linux lab Advanced 5 tasks 30 points

Write healthcheck.sh, a script that checks a short list of things a server needs and reports OK or FAIL for each, like a real monitoring script. Use a function so each check is one line.

How it works: the terminal below is a real Linux machine running in your browser. Click it and type. Tasks tick themselves off as you complete them; questions are answered in the box under each task. Press Reset any time for a fresh machine. Your password on this machine (for sudo) is student.

Getting your Linux machine ready…

The first start downloads about 20 MB. After that your browser keeps it, and labs start in a moment.

Hints

Write the function first and call it once; add the checks when it works.

"$@" inside the function runs whatever command and arguments you passed after the label.

Solution explanation

The check function takes a label and then a command to run. It runs the command quietly and prints OK or FAIL, setting fail=1 on any failure. id deploy and test -s /srv/app/config are ordinary commands whose exit codes say whether the check passed, and exit $fail makes the whole script succeed only if nothing failed.

Show solution

cat <<'EOF' > healthcheck.sh
#!/bin/bash
fail=0
check() {
  local label=$1; shift
  if "$@" >/dev/null 2>&1; then
    echo "$label: OK"
  else
    echo "$label: FAIL"
    fail=1
  fi
}
check "user deploy" id deploy
check "config present" test -s /srv/app/config
exit $fail
EOF
chmod +x healthcheck.sh
./healthcheck.sh; echo $?