#!/bin/bash
#
# Copyright 2014 Red Hat, Inc.
#
# NAME
#     lab-nfsshare - grading script for RH254/RH299 NFS practice exercise
#
# SYNOPSIS
#     lab-nfsshare grade
#
#     This script only works on both desktopX and serverX.
#
# DESCRIPTION
#     This script is the grading script for a RH254 NFS practice
#     exercise.
#
# CHANGELOG
#   * Mon Jun 16 2014 George Hacker <ghacker@redhat.com>
#   - fixed this script so that it runs as root (required)
#   * Thu May 15 2014 Rudy Kastl <rkastl@redhat.com>
#   - original code

# Initialize and set some variables
MYHOST=""
CMD=""
RUN_AS_ROOT=true

SERV_PKG="sssd krb5-workstation"
CLNT_PKG="sssd krb5-workstation"
SERV_ERR="Error running script. Did you reset the server before running this script? \
Contact your instructor if you continue to see this message."
CLNT_ERR="Error running script. Did you reset the desktop before running this script? \
Contact your instructor if you continue to see this message."

# Source library of functions
source /usr/local/bin/labtool.shlib
trap on_exit EXIT
LOG_TAG=$(basename $0)

# Additional functions for this shell script
function srv_exit {
  # call debug with msg and exit with code
  DEBUG=true
  debug "$1"
  exit $2
}

# Grading scripts server
function check_enabled_nfs_server {
  echo -n "Checking nfs-server service is enabled... "
  if systemctl is-enabled nfs-server &> /dev/null
  then
    print_PASS
  else
    print_FAIL
    echo "Service nfs-server is not enabled."
    return 1
  fi
}

function check_isactive_nfs_server {
  echo -n "Checking nfs-server service is started... "
  if systemctl is-active nfs-server &> /dev/null
  then
    print_PASS
  else
    print_FAIL
    echo "Service nfs-server is not started."
    return 1
  fi
}

function check_nfs_share_dir_exists {
  echo -n "Checking /nfsshare directory exists... "
  if [ -d /nfsshare ]
  then
    print_PASS
  else
    print_FAIL
    echo "The /nfsshare directory does not exist."
    return 1
  fi
}

function check_nfs_export {
  echo -n "Checking for correct /etc/exports file... "
  if ! grep '/nfsshare' /etc/exports &>/dev/null
  then
    print_FAIL
    echo "The /nfsshare entry in /etc/exports does not exist."
    return 1
  elif ! (grep '/nfsshare' /etc/exports |grep 'desktop') &>/dev/null
    then
      print_FAIL
      echo "The /nfsshare entry in /etc/exports does not export to the desktopX system."
      return 1
  elif ! (grep '/nfsshare' /etc/exports |grep 'rw') &>/dev/null
    then
      print_FAIL
      echo "The /nfsshare entry in /etc/exports does not export with read-write permission."
      return 1
  else
    print_PASS
  fi
}

function check_exportfs {
  echo -n "Checking if the server knows about the exported directory... "
  if exportfs -v |grep '/nfsshare' &>/dev/null
  then
    print_PASS
  else
    print_FAIL
    echo "Did you forget to run: exportfs -r?"
    return 1
  fi
}

# Grading scripts desktop
function check_nfs_mountpoint {
  echo -n "Checking /mnt/nfsshare directory exists..."
  if [ -d /mnt/nfsshare ]
  then
    print_PASS
  else
    print_FAIL
    echo "The /mnt/nfsshare directory does not exist."
    return 1
  fi
}

function check_nfs_fstab {
  echo -n "Checking for correct /etc/fstab entry..."
  if ! (grep 'server.*:/nfsshare.*/mnt/nfsshare.*nfs.*' /etc/fstab) &>/dev/null
  then
    print_FAIL
    echo "The /etc/fstab entry is not present or not correct."
    return 1
  else
    print_PASS
  fi
}

function check_nfs_mounted {
  echo -n "Checking for mounted nfs share ..."
  if ! (mount |grep 'server.*:/nfsshare.*/mnt/nfsshare.*nfs4') &>/dev/null
  then
    print_FAIL
    echo "The nfs share is not mounted."
    return 1
  else
    print_PASS
  fi
}

function check_nfsmount_writeable {
  echo -n "Checking if nfs mount is writeable for nfsnobody ..."
  rm -f /mnt/nfsshare/mytestfile123321.txt &>/dev/null
  if ! touch /mnt/nfsshare/mytestfile123321.txt &>/dev/null
  then
    print_FAIL
    echo "The nfs share is not writable by nfsnobody."
    return 1
  else
    print_PASS
  fi
}


function print_usage {
echo "This script controls the setup and grading of this lab."
echo "Usage: $(basename $0) COMMAND"
echo "       $(basename $0) -h|--help"
echo "COMMAND is one of:"
echo "    setup - perform any setup steps for this lab on this machine"
echo "    grade - perform any grading steps and report on this machine"

}

function lab_setup {
    VMNAME=$1
    case $VMNAME in
        desktop)
            ERROR_MESSAGE="$CLNT_ERR"
            echo "This lab does not require setup."
            print_SUCCESS
            ;;
        server)
            ERROR_MESSAGE="$SERV_ERR"
            echo "This lab does not require setup."
            print_SUCCESS
            ;;
        *)
            # Should never get here, but what the hey....
            print_FAIL && echo "This lab does not require setup."
            ;;
    esac
}

function lab_grade {
    VMNAME=$1
    case $VMNAME in
        desktop)
            FAIL=0
            echo "Grading exercise IP-based NFS..."
            check_nfs_mountpoint || FAIL=1
            check_nfs_fstab || FAIL=1
            check_nfs_mounted || FAIL=1
            check_nfsmount_writeable || FAIL=1
            echo
            echo -n "Overall result: "
            if [ ${FAIL} -eq 0 ]; then
              print_PASS
              echo "Congratulations! You've passed all requirements."
            else
              print_FAIL
              echo "Please check your work and try again."
            fi
            ;;
        server)
            FAIL=0
            echo "Grading exercise IP-based NFS..."
            check_isactive_nfs_server || FAIL=1
            check_enabled_nfs_server || FAIL=1
            check_nfs_share_dir_exists || FAIL=1
            check_nfs_export || FAIL=1
            check_exportfs || FAIL=1
            echo
            echo -n "Overall result: "
            if [ ${FAIL} -eq 0 ]; then
              print_PASS
              echo "Congratulations! You've passed all requirements."
            else
              print_FAIL
              echo "Please check your work and try again."
            fi
            ;;
        *)
            # Should never get here, but what the hey....
            print_FAIL && echo "Something went wrong. Ask your instructor for assistance."
            ;;
    esac
}

# Main area

# Check if to be run as root (must do this first)
if [[ "${RUN_AS_ROOT}" == 'true' ]] && [[ "${EUID}" -gt "0" ]] ; then
  if [[ -x /usr/bin/sudo ]] ; then
    ${SUDO:-sudo} $0 "$@"
    exit
  else
    # Fail out if not running as root
    check_root
  fi
fi

# Process command line
# Parse input
case $1 in
    setup|grade)
        CMD=$1
        ;;
    -h|--help)
        print_usage
        exit 0
        ;;
    *)
        echo Bad option $1
        print_usage
        exit 1
        ;;
esac
# Validation
[ -z "$CMD" ] && debug "Missing command" && print_usage && exit 1

# Get local system information
get_X

# Branch based on short (without number) hostname
case $MYHOST in
    desktop|server)
        lab_$CMD $MYHOST
        ;;
    *)
        debug "Bad or missing hostname - $MYHOST"
        debug "This command needs to be run on desktop or server"
        exit 3
        ;;
esac