#!/bin/bash
#
# Service Library Usage Check 
#
# Copyright 2016 Steadfast Networks, LLC
#
# This script checks to see if any services should be restarted after a library update
# Provide a list of package names or library sonames you want to check on the command line

OLDIFS=$IFS
LIBS="$@ "
SERVICES=
if [[ `uname -m` == 'x86_64' ]] ; then
  LIBDIR='/usr/lib64'
else
  LIBDIR='/usr/lib'
fi

rpm --version >/dev/null 2>&1
if [[ $? -ne 0 ]] ; then
  echo "Error: Need RPM to continue.  Maybe this isn't CentOS?";
  exit 1;
fi
for LIB in $LIBS; do
  echo $LIB | grep '\.' >/dev/null
  if [[ $? -ne 0 ]] ; then
    RPMLIBS=`rpm -ql $LIB | grep "\.so\.\?" | tr '\n' ' '`
    COUNT=(${RPMLIBS})
    COUNT=${#COUNT[@]}
    echo "+ Using $LIB as RPM name, found $COUNT libraries"
    LIBS="`echo $LIBS | sed 's/'$LIB'\( \|$\)//'` $RPMLIBS"
  fi
done

OSVER=`rpm -q centos-release --queryformat="%{VERSION}"`
for LIB in $LIBS; do
  if [[ `basename $LIB` == $LIB ]] ; then
    LIB=$LIBDIR/$LIB
  fi
  if [[ $OSVER -eq 5 ]] ; then
    MSTRING=n${LIB}'\s.path\sinode'
  elif [[ $OSVER -eq 6 ]] ; then
    MSTRING="fDEL n${LIB}"
  else
    MSTRING="n${LIB};"
  fi
  LIBFN=`basename $LIB`
  MATCH=`lsof -F fpn / | grep '^\(f\|p\|n\)' | tr '\n' ' ' | sed 's/ p/\np/g' | grep "${MSTRING}" | sed 's/^p\([0-9]\+\) f.*$/\1/'i`
  MATCHES="$MATCHES $MATCH"
  if [[ $MATCH != "" ]] ; then
    echo "+ Found $LIBFN PID matches: "$MATCH
  else
    echo "- Nothing was found running on an old $LIBFN"
  fi
done

EXES=""
# Deduplicate the PID list
MATCHES=`echo $MATCHES | tr ' ' '\n' | sort -n | uniq`
for PID in $MATCHES; do
  EXE=`readlink /proc/$PID/exe | sed 's/;.*$//' | sed 's/ (deleted)//'`
  # If this is a script, try to figure out what script was run and match the package for that instead 
  if [[ $EXE =~ /python || $EXE =~ /php || $EXE =~ /perl || $EXE =~ /sh || $EXE =~ /bash || $EXE =~ /ruby ]] ; then
    SCRIPT=`sed 's/\x00/\n/g' /proc/$PID/cmdline | tail -n +2 | grep '\(libexec\|bin\)'`
    if [[ $SCRIPT != "" ]] ; then
      EXE=$SCRIPT
    fi
  fi
  EXES="$EXES $EXE"
done

# Deduplicate the EXE list
EXES=`echo $EXES | tr ' ' '\n' | sort | uniq`
for EXE in $EXES; do 
  PACKAGE=`rpm -qf $EXE 2>/dev/null`
  if [[ $PACKAGE == "" ]] ; then
    NOPKG="$NOPKG $EXE"
  else
    if [[ $OSVER -ge 7 ]] ; then
      SVCS=`rpm -qf $EXE -l 2>/dev/null | grep '\.service$'`
    else
      SVCS=`rpm -qf $EXE -l 2>/dev/null | grep '/init.d/'`
    fi
    if [[ $SVCS == "" ]] ; then
      NOSVC="$NOSVC $EXE"
    fi
    for SVC in $SVCS; do
      SERVICES="$SERVICES `basename $SVC | sed 's/.service$//'`"
    done
  fi
done
if [[ $SERVICES != "" ]] ; then
  echo
  echo "You probably need to do the following:"
  echo
  for RESTART in `echo $SERVICES | sed 's/ /\n/g' | sort -u`; do
    service $RESTART status >/dev/null 2>&1
    if [[ $? -eq 0 ]] ; then
      SVCFOUND=1
      if [[ $OSVER -ge 7 ]] ; then
        echo "  systemctl restart $RESTART"
      else
        echo "  service $RESTART restart"
      fi
    fi
  done
  if [[ $SVCFOUND -ne 1 ]] ; then
    echo " * Some startup scripts matched, but none are running, so nothing seems relevant."
  fi
fi
if [[ $NOSVC != "" || $NOPKG != "" ]] ; then
  echo
  echo "You're on your own with these:"
  echo
  for EXE in `echo $NOPKG | sed 's/ /\n/g' | grep -v '(deleted)' | sort -u`; do
    echo "* The program $EXE does not appear to come from an installed package."
  done
  for EXE in `echo $NOSVC | sed 's/ /\n/g' | sort -u`; do
    echo "* The program $EXE does not appear to have any relevant services."
  done
fi
if [[ $SERVICES == "" && $NOSVC == "" && $NOPKG == "" ]] ; then
  echo
  echo "Good news! Nothing seems to need to be restarted."
fi
echo