#!/usr/bin/env bash

# This program is part of Percona Toolkit: http://www.percona.com/software/
# See "COPYRIGHT, LICENSE, AND WARRANTY" at the end of this file for legal
# notices and disclaimers.

# ###########################################################################
# log_warn_die package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/bash/log_warn_die.sh
#   t/lib/bash/log_warn_die.sh
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################

set -u

EXIT_STATUS=0

log() {
   TS=$(date +%F-%T | tr :- _);
   echo "$TS $1"
}

warn() {
   log "$1" >&2
   EXIT_STATUS=$((EXIT_STATUS | 1))
}

die() {
   warn "$1"
   exit 1
}

# ###########################################################################
# End log_warn_die package
# ###########################################################################

# ###########################################################################
# parse_options package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/bash/parse_options.sh
#   t/lib/bash/parse_options.sh
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################

set -u

declare -a ARGV   # non-option args (probably input files)
declare EXT_ARGV  # everything after -- (args for an external command)
OPT_ERR=${OPT_ERR:""}

usage() {
   local file=$1

   local usage=$(grep '^Usage: ' $file)
   local opts=$(grep -A 2 '^=item --' $file | sed -e 's/^=item //' -e 's/^\([A-Z]\)/   \1/' -e 's/^--$//' > $TMPDIR/help)

   if [ "$OPT_ERR" ]; then
      echo "Error: ${OPT_ERR}" >&2
   fi
   echo $usage >&2
   echo >&2
   echo "Options:" >&2
   echo >&2
   cat $TMPDIR/help >&2
   echo >&2
   echo "For more information, 'man $TOOL' or 'perldoc $file'." >&2
}

parse_options() {
   local file=$1
   shift

   local opt=""
   local val=""
   local default=""
   local version=""
   local i=0

   awk '
      /^=head1 OPTIONS/ {
         getline
         while ($0 !~ /^=head1/) {
            if ($0 ~ /^=item --.*/) {
               long_opt=substr($2, 3, length($2) - 2)
               short_opt=""
               required_arg=""

               if ($3) {
                  if ($3 ~ /-[a-z]/)
                     short_opt=substr($3, 3, length($3) - 3)
                  else
                     required_arg=$3
               }

               if ($4 ~ /[A-Z]/)
                  required_arg=$4

               getline # blank line
               getline # short description line

               if ($0 ~ /default: /) {
                  i=index($0, "default: ")
                  default=substr($0, i + 9, length($0) - (i + 9))
               }
               else
                  default=""

               print long_opt "," short_opt "," required_arg "," default
            }
            getline
         }
         exit
      }' $file > $TMPDIR/options

   while read spec; do
      opt=$(echo $spec | cut -d',' -f1 | sed 's/-/_/g' | tr [:lower:] [:upper:])
      default=$(echo $spec | cut -d',' -f4)
      eval "OPT_${opt}"="$default"
   done < <(cat $TMPDIR/options)

   for opt; do
      if [ $# -eq 0 ]; then
         break
      fi
      opt=$1
      if [ "$opt" = "--" ]; then
         shift
         EXT_ARGV="$@"
         break
      fi
      if [ "$opt" = "--version" ]; then
         version=$(grep '^pt-[^ ]\+ [0-9]' $0)
         echo "$version"
         exit 0
      fi
      if [ "$opt" = "--help" ]; then
         usage $file
         exit 0
      fi
      shift
      if [ $(expr "$opt" : "-") -eq 0 ]; then
         ARGV[i]="$opt"
         i=$((i+1))
         continue
      fi
      opt=$(echo $opt | sed 's/^-*//')
      spec=$(grep -E "^$opt,|,$opt," "$TMPDIR/options")
      if [ -z "$spec"  ]; then
         die "Unknown option: $opt"
      fi
      opt=$(echo $spec | cut -d',' -f1)
      required_arg=$(echo $spec | cut -d',' -f3)
      val="yes"
      if [ -n "$required_arg" ]; then
         if [ $# -eq 0 ]; then
            die "--$opt requires a $required_arg argument"
         else
            val="$1"
            shift
         fi
      fi
      opt=$(echo $opt | sed 's/-/_/g' | tr [:lower:] [:upper:])
      eval "OPT_${opt}"="$val"
   done
}

# ###########################################################################
# End parse_options package
# ###########################################################################

# ###########################################################################
# tmpdir package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/bash/tmpdir.sh
#   t/lib/bash/tmpdir.sh
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################

set -u

TMPDIR=""
OPT_TMPDIR=${OPT_TMPDIR:""}

mk_tmpdir() {
   if [ -n "$OPT_TMPDIR" ]; then
      TMPDIR="$OPT_TMPDIR"
      if [ ! -d "$TMPDIR" ]; then
         mkdir $TMPDIR || die "Cannot make $TMPDIR"
      fi
   else
      local tool=`basename $0`
      local pid="$$"
      TMPDIR=`mktemp -d /tmp/${tool}.${pid}.XXXXX` \
         || die "Cannot make secure tmpdir"
   fi
}

rm_tmpdir() {
   if [ -n "$TMPDIR" ] && [ -d "$TMPDIR" ]; then
      rm -rf $TMPDIR
   fi
   TMPDIR=""
}

# ###########################################################################
# End tmpdir package
# ###########################################################################

# ###########################################################################
# Subroutines
# ###########################################################################
set +u

grep_processlist() {
   local file=$1
   local col=$2
   local pat=${3:-""}
   local gt=${4:-0}
   local quiet=${5:-0}

   awk "
      BEGIN {
         FS=\"|\"
         OFS=\" | \"
         n_cols=0
         found=0
      }

      /^\|/ {
         if ( n_cols ) {
            val=colno_for_name[\"$col\"]
            if ((\"$pat\"  && match(\$val, \"$pat\")) || ($gt && \$val > $gt) ) {
               found++
               if (!$quiet) print \$0
            }
         }
         else {
            for (i = 1; i <= NF; i++) {
               gsub(/^[ ]*/, \"\", \$i)
               gsub(/[ ]*$/, \"\", \$i)
               if ( \$i != \"\" ) {
                  name_for_colno[i]=\$i
                  colno_for_name[\$i]=i
                  n_cols++
               }
            }
         }
      }

      END {
         if ( found )
            exit 0
         exit 1
      }
   " $file
}

set_trg_func() {
   if [ -f "$OPT_TRIGGER_FUNCTION" ]; then
      source $OPT_TRIGGER_FUNCTION
      TRIGGER_FUNCTION="trg_plugin"
   else
      TRIGGER_FUNCTION="trg_$OPT_TRIGGER_FUNCTION"
   fi
}

trg_status() {
   local var=$1
   mysqladmin "$EXT_ARGV" extended-status | grep "$OPT_VARIABLE" | awk '{print $4}'
}

trg_processlist() {
   local var=$1
   local tmpfile="$TMPDIR/processlist"
   mysqladmin "$EXT_ARGV" processlist              > $tmpfile-1
   grep_processlist $tmpfile-1 $var $OPT_MATCH 0 0 > $tmpfile-2
   wc -l $tmpfile-2 | awk '{print $1}'
   rm -rf $tmpfile*
   return
}

trg_magic() {
   echo "TODO"
   return
}

# ###########################################################################
# Main program loop, called below if tool is ran from the command line.
# ###########################################################################

main() {
   mk_tmpdir
   parse_options $0 "$@"

   # Make the collection location
   # mkdir -p "$OPT_DEST" || die "Can't make the destination directory"
   # test -d "$OPT_DEST"  || die "$OPT_DEST isn't a directory"
   # test -w "$OPT_DEST"  || die "$OPT_DEST isn't writable"

   # Test if we have root; warn if not, but it isn't critical.
   if [ "$(id -u)" != "0" ]; then
      echo 'Not running with root privileges!';
   fi

   # We increment this variable every time that the check is true,
   # and set it to 0 if it's false.
   local cycles_true=0
   local matched="no"

   set_trg_func

   while true; do

      # This is where we decide whether to execute 'collect'.
      # The idea is to generate a number and store into $detected,
      # and if $detected > $OPT_THRESHOLD, then we'll execute pt-collect.
      local value=$($TRIGGER_FUNCTION $OPT_VARIABLE)
      local trg_exit_status=$?

      if [ -z "$value" ]; then
         # No value.  Maybe we failed to connect to MySQL?
         warn "Detected value is empty; something failed?  Trigger exit status: $trg_exit_status"
         matched="no"
         cycles_true=0
      elif [ $value -gt $OPT_THRESHOLD ]; then
         matched="yes"
         cycles_true=$(($cycles_true + 1))
      else
         matched="no"
         cycles_true=0
      fi

      log "Check results: $OPT_VARIABLE=$value, matched=$matched, cycles_true=$cycles_true"

      if [ "$matched" = "yes" -a $cycles_true -ge $OPT_CYCLES ]; then 
         log "$OPT_COLLECT triggered"

         # PREFIX="$(date +%F-%T | tr :- _)"
         # echo "${NOTE}" > "${DEST}/${PREFIX}-trigger"

         # Run pt-collect.
         $OPT_COLLECT               \
            -i "$OPT_RUN_TIME"      \
            -g "$OPT_GDB"           \
            -o "$OPT_OPROFILE"      \
            -p "$OPT_PREFIX"        \
            -s "$OPT_STRACE"        \
            -t "$OPT_TCPDUMP"       \
            -f "$OPT_PCT_THRESHOLD" \
            -m "$OPT_MB_THRESHOLD"  \
            -- "$EXT_ARGV"

         log "Sleeping $OPT_SLEEP seconds to avoid DOS attack"
         sleep $OPT_SLEEP
      else
         sleep $OPT_INTERVAL
      fi

      # Delete things more than $PURGE days old
      #find "$OPT_DEST" -type f -mtime +$OPT_PURGE -exec rm -f '{}' \;
      #find "/var/lib/oprofile/samples" -type d -name 'pt_collect_*' \
      #   -depth -mtime +$OPT_PURGE -exec rm -f '{}' \;

   done

   # Remove the secure tmpdir.  This is not actually called because
   # this tool runs forever.
   rm_tmpdir
}

# Execute the program if it was not included from another file.
# This makes it possible to include without executing, and thus test.
if [ "$(basename "$0")" = "pt-stalk" ] || [ "$(basename "$0")" = "bash" -a "$_" = "$0" ]; then
   main "$@"
fi

exit $EXIT_STATUS

# ############################################################################
# Documentation
# ############################################################################
:<<'DOCUMENTATION'
=pod

=head1 NAME

pt-stalk - Wait for a condition to occur then begin collecting data.

=head1 SYNOPSIS

Usage: pt-stalk [OPTIONS] [-- MYSQL OPTIONS]

pt-stalk watches for a condition to become true, and when it does, executes
a script.  By default it executes L<pt-collect>, but that can be customized.
This tool is useful for gathering diagnostic data when an infrequent event
occurs, so an expert person can review the data later.

=head1 RISKS

The following section is included to inform users about the potential risks,
whether known or unknown, of using this tool.  The two main categories of risks
are those created by the nature of the tool (e.g. read-only tools vs. read-write
tools) and those created by bugs.

pt-stalk is a read-only tool.  It should be very low-risk.

At the time of this release, we know of no bugs that could cause serious harm
to users.

The authoritative source for updated information is always the online issue
tracking system.  Issues that affect this tool will be marked as such.  You can
see a list of such issues at the following URL:
L<http://www.percona.com/bugs/pt-stalk>.

See also L<"BUGS"> for more information on filing bugs and getting help.

=head1 DESCRIPTION

Although pt-stalk comes pre-configured to do a specific thing, in general
this tool is just a skeleton script for the following flow of actions:

=over

=item 1.

Loop infinitely, sleeping between iterations.

=item 2.

In each iteration, run some command and get the output.

=item 3.

If the command fails or the output is larger than the threshold,
execute the collection script; but do not execute if the destination disk
is too full.

=back

By default, the tool is configured to execute mysqladmin extended-status and
extract the value of the Threads_running variable; if this is greater than
25, it runs the collection script.  This is really just placeholder code,
and almost certainly needs to be customized!

If the tool does execute the collection script, it will wait for a while
before checking and executing again.  This is to prevent a continuous
condition from causing a huge number of executions to fire off.

The name 'stalk' is because 'watch' is already taken, and 'stalk' is fun.

=head1 CONFIGURING

TODO

=head1 OPTIONS

=over

=item --collect DIRECTORY

Location of the C<collect> tool. (default: ${HOME}/bin/pt-collect)

=item --cycles N

Number of times condition must be met before triggering collection. (default: 5)

=item --dest DIRECTORY 

Where to store collected data.

=item --disk-byte-limit MEGABYTES

Exit if the disk has less than this many MB free. (default: 100)

=item --disk-pct-limit PERCENT

Exit if the disk is less than this %full. (default: 5)

=item --email ADDRESS

Send mail to this list of addresses when the script triggers.

=item --gdb

Collect GDB stacktraces.

=item --help

Print help and exit.

=item --interval SECONDS

Interval between checks. (default: 1)

=item --match PATTERN

Match pattern for C<processles> L<"--trigger-function">.

=item --oprofile

Collect oprofile data. (default: yes)

=item --purge DAYS

Remove samples after this many days. (default: 30)

=item --run-time SECONDS

How long to collect statistics data for? (default: 30)

Make sure that this isn't longer than SLEEP.

=item --strace

Collect strace data.

=item --sleep SECONDS

How long to sleep after collecting? (default: 300)

=item --tcpdump

Collect tcpdump data? (default: yes)

=item --trigger-function

Built-in function name or plugin file name which returns the value of C<VARIABLE>.  (default: status)

Possible values are:

=over

=item * status

Grep the value of C<VARIABLE> from C<mysqladmin extended-status>.

=item * processlist

Count the number of processes in C<mysqladmin processlist> whose
C<VARIABLE> column matches C<MATCH>.  For example:

   TRIGGER_FUNCTION="processlist" \
   VARIABLE="State"               \
   MATCH="statistics"             \
   THRESHOLD="10"

The above triggers when more than 10 processes are in the "statistics" state.
C<MATCH> must be specified for this trigger function.

=item * magic

TODO

=item * plugin file name

A plugin file allows you to specify a custom trigger function.  The plugin
file must contain a function called C<trg_plugin>.  For example:

   trg_plugin() {
      # Do some stuff.
      echo "$value"
   }

The last output if the function (its "return value") must be a number.
This number is compared to C<THRESHOLD>.  All L<"ENVIRONMENT"> variables
are available to the function.

Do not alter the tool's existing global variables.  Prefix any plugin-specific
global variables with "PLUGIN_".

=back

=item --threshold N

Max number of C<N> to tolerate. (default: 25)

=item --variable NAME

This is the thing to check for. (default: Threads_running)

=item --version

Print tool's version and exit.

=back

=head1 ENVIRONMENT

No env vars used.

=head1 SYSTEM REQUIREMENTS

This tool requires Bash v3 or newer.

=head1 BUGS

For a list of known bugs, see L<http://www.percona.com/bugs/pt-stalk>.

Please report bugs at L<https://bugs.launchpad.net/percona-toolkit>.
Include the following information in your bug report:

=over

=item * Complete command-line used to run the tool

=item * Tool L<"--version">

=item * MySQL version of all servers involved

=item * Output from the tool including STDERR

=item * Input files (log/dump/config files, etc.)

=back

If possible, include debugging output by running the tool with C<PTDEBUG>;
see L<"ENVIRONMENT">.

=head1 DOWNLOADING

Visit L<http://www.percona.com/software/percona-toolkit/> to download the
latest release of Percona Toolkit.  Or, get the latest release from the
command line:

   wget percona.com/get/percona-toolkit.tar.gz

   wget percona.com/get/percona-toolkit.rpm

   wget percona.com/get/percona-toolkit.deb

You can also get individual tools from the latest release:

   wget percona.com/get/TOOL

Replace C<TOOL> with the name of any tool.

=head1 AUTHORS

Baron Schwartz, Justin Swanhart, Fernando Ipar, and Daniel Nichter

=head1 ABOUT PERCONA TOOLKIT

This tool is part of Percona Toolkit, a collection of advanced command-line
tools developed by Percona for MySQL support and consulting.  Percona Toolkit
was forked from two projects in June, 2011: Maatkit and Aspersa.  Those
projects were created by Baron Schwartz and developed primarily by him and
Daniel Nichter, both of whom are employed by Percona.  Visit
L<http://www.percona.com/software/> for more software developed by Percona.

=head1 COPYRIGHT, LICENSE, AND WARRANTY

This program is copyright 2010-2011 Baron Schwartz, 2011 Percona Inc.
Feedback and improvements are welcome.

THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, version 2; OR the Perl Artistic License.  On UNIX and similar
systems, you can issue `man perlgpl' or `man perlartistic' to read these
licenses.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA  02111-1307  USA.

=head1 VERSION

pt-stalk 2.0.0

=cut

DOCUMENTATION