tidhub.sh

#!/bin/bash

########################################
### Global constants/variables
########################################

declare -A WIKI # declare user defined associative array
rcfile=~/.config/tidhub/tidhubrc # path to config file containing WIKI array
rctempl="# This file is sourced from tidhub.sh

# This file contains wiki associative array definition: WIKI[key]=value.
#   'Key'   is the unique user defined identifier of user's wiki instance.
#   'Value' is the path to the wiki instance — i.e. to the directory
#           where 'tiddlywiki.info' file is at the top.

WIKI[hnts]=~/Notes/home_notes/
WIKI[wnts]=~/Notes/work_notes/
WIKI[train]=~/Training/my_journal/
WIKI[3]=~/Todo/"
wiki_status_csv="" # wiki status CSV list


########################################
### Functions definitions follows
########################################


########################################
# Print TidHub version and copyright
#
# Outputs:
#   STDOUT TidHub version info
########################################
print_version () {
  cat << _EOF_
Version: 1.0.2, date 2021-01-20

Copyright notice:
    Copyright  2021 by MarHaj at https://github.com/MarHaj/tidhub
    under GNU General Public Licence version 3 or later:
    https://www.gnu.org/licenses/gpl-3.0.txt

    This is free software, and you are welcome to redistribute it
    under conditions of GNU GPL Licence.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty
    of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    See the GNU General Public License for more details.
_EOF_
}
########################################

########################################
# Print short usage
########################################
print_usage () {
  cat << _EOF_
Usage: tidhub.sh [option] | [command] [keylist]
  Options: [-h|--help] | [-s|--status] | [-v|--version]
  Commands: start | stop | view
    Keylist: space separated wiki keys (see --help)
_EOF_
}
########################################

########################################
# Check existence of rcfile and
# create it from the template if doesn't exist
#
# Globals:
#   rcfile used
#   rctempl used
#
# Outputs:
#   STDERR: if rcfile missing
#   STDERR: if unrecognised user input
#   STDERR: if unable to create rcfile
#   rcfile: if user interractively agrees about creating this file (incl dir)
#
# Returns:
#   exit 0: user responds not to create file by tidhub
#   exit 1: unregognised user input
#   exit 2: unable to create rcfile
########################################
check_rc () {
  local rcdir="${rcfile%/*}"

  if [[ ! -r "${rcfile}" ]]; then
    echo "ERR: required config file '$rcfile' is missing." >&2
    read -n 1 -p "Can I create it? Reply: y|n > "
    echo ""
    if [[ $REPLY == n ]]; then
      echo -e "\nYou should create '$rcfile' by yourself. It's required by tidhub."
      exit 0
    elif [[ $REPLY == y ]]; then
      [[ -d "${rcdir}" ]] || mkdir "$rcdir" && echo "$rctempl" > "$rcfile"
      if [[ -r "${rcfile}" ]]; then
        echo -e  "\nFile '$rcfile' successfully created."
        echo "You should edit it to reflect your own wikis placement."
      else
        echo -e "\nERR: unable to create '$rcfile'. Something is wrong." >&2
        exit 1
      fi
    else
      echo -e "\nERR: reply unregognized." >&2
      exit 2
    fi
  fi
}
########################################

########################################
# Print detailed help
########################################
print_help (){

  cat << _EOF_
Purpose:
  Manage multiple local 'Tiddlywikis' on 'Node.js'

Usage:
  There are two modes of usage: Informative and Executive.

  Informative mode of usage: tidhub.sh [option]
    Options:
      [-h|--help]           print this document default, i.e. when no option or
                            command is provided)
      [-s|--status]         print status info about configured and running wikis
      [-v|--version]        print program version
      [ ]                   print short usage info

  Executive mode of usage: tidhub command [keylist]
    Commands:
      start                 start wikis
      stop                  stop wikis
      view                  view vikis in the default browser

      [keylist]             list of wiki keys (see below) separated by space.
                            If no keylist is provided, then command will be
                            executed on all configured wikis possible.

  Usage examples:
    tidhub -s               print status info about wikis
    tidhub start hnts 3     start wikis identified by the keys 'hnts' and '3'
    tidhub stop 3           stop wiki identified by the key '3'

Configuration:
    TidHub makes use of '~/${rcfile#/*/*/}' file, where you have to configure
    your specific wikis setup.
    If the file does'not exist it will be automatically created from the template.
    You have to edit it to reflect your own wikis specifications.
    How to do it can be found directly in the file itself.
    See the template/example below:
--------------------------------------
${rctempl}
--------------------------------------

Requirements:
  External programs required by TidHub:
    Tiddlywiki on Node.js, awk, sed, pgrep, ss|netstat
    xdg-open|x-wwwbrowser|sensible-browser
_EOF_
}
########################################

########################################
# Make CSV config list from wiki array
# and remove element with repeating value (path) if exists
#
# Globals:
#   WIKI: array used
#
# Outputs:
#   STDOUT: CSV list of configured wiki: key,path,,
########################################
conf2csv () {
  local i j

# clear WIKI from posssible repeating paths
  for i in ${!WIKI[@]}; do
    for j in ${!WIKI[@]}; do
      if [[ $i != $j ]]; then
        [[ "${WIKI[$i]}" == "${WIKI[$j]}" ]] && unset 'WIKI[$j]'
      fi
    done
  done

# make csv
  for i in ${!WIKI[@]}; do
    echo "$i,"${WIKI[$i]}",,"
  done
}
########################################

########################################
# Make CSV list of live wikis
# Filter ouput only to processes that contain 'tiddlywiki' word in command line
#
# Outputs:
#   STDOUT: CSV list of running wikis: ,path,pid,port
#
# Requires:
#   EXT: pgrep, awk
########################################
live2csv () {
# output from $(pgrep -a node)
  pgrep -a node | \
    awk '$3 ~ /tiddlywiki$/ { sub(/port=/,"",$6) ; print ","$4","$1","$6 }'
}
########################################

########################################
# Merge conf and live CSV lists
# Merging based on common field "path to wiki"
# Output also live and not configured wikis
#
# Outputs:
#   STDOUT: csv status list: key,path,pid,port
#
# Requires:
#   INT: conf2csv, live2csv
#   EXT: sed
########################################
merge_csv () {
  local live_line
  local conf_line
  local output_line=""
  local live_list="$(live2csv)"

  while IFS=, read -r -a conf_line; do # loop config
    output_line=$(printf '%s,%s,%s,%s\n' "${conf_line[@]}")
    while IFS=, read -r -a live_line; do # loop live
      if [[ "${conf_line[1]}" == "${live_line[1]}" ]]; then # merge lines
        output_line="${conf_line[0]},${conf_line[1]},${live_line[2]},${live_line[3]}"
        live_list=$(echo "$live_list" \
          | sed "/${live_line[3]}/d") # remove this line from live_list
        break # no need to continue inner loop
      fi
    done <<< "$(live2csv)"
    echo "$output_line"
  done <<< "$(conf2csv)"
  echo "$live_list" # remaning live_list
}
########################################

########################################
# Create global wiki_status_csv list
# If config path does not point to tiddlywiki.info then add prefix 'WNA: '.
#
# Globals:
#   wiki_status_csv: changed
#
# Outputs:
#   csv list: key,path,pid,port
#
# Requires:
#   INT: merge_csv
########################################
mk_wiki_status () {
  local line
  wiki_status_csv=""

  while IFS=, read -r -a line; do
    [[ -f "${line[1]}tiddlywiki.info" ]] || line[1]="WNA: ${line[1]}"
    echo "${line[0]},${line[1]},${line[2]},${line[3]}"
  done <<< $(merge_csv)
}
########################################

########################################
# Prints formatted wiki status with header and footer
#
# Globals:
#   wiki_status_csv: used
#
# Outputs:
#   STDOUT: CSV list: key,path,pid,port + footer if WMA found
#
# Requires:
#   EXT: awk
########################################
print_status () {
  local header="KEY,PATH,PID,PORT"
  local footer="WNA: this Wiki Not Avalilable on the path configured"
  local mxpl # maximum of paths lengths

# determine max path length for formatting purpose
  mxpl=$(echo "${wiki_status_csv}" \
    | awk -F, '{ if (length($2) > max) max = length($2)} END { print max }'
  )
  (( $mxpl < 4 )) && mxpl=6 || mxpl=$(( $mxpl + 2 ))

# final output
  echo -e "${header}\n${wiki_status_csv}" | \
    awk -F, -v afoot="$footer" \
      'BEGIN { print "--------" } \
      { printf( "%-8s %-'${mxpl}'s %-6s %-6s \n", $1, $2, $3, $4); \
        if ( $2 ~ /^WNA:\s/ ) foot_flag = 1; \
      } \
      END { print "--------"; if ( foot_flag ) print afoot}'
}
########################################

########################################
# Run provided url in the default browser
#
# Arguments:
#   $1: url
#
# Outputs:
#   STDERR: if requirements are not met
#
# RETURNS
#   exit 3: if requirements are not met
#
# Requires:
#   EXT: xdg-open|x-www-browser|sensible-browser
########################################
run_browser () {
  local url=$1
  local msg="required app
 'xdg-open'|'x-www-browser'|'sensible-browser' not installed."

  xdg-open $url 1>/dev/null 2>&1 \
  || x-www-browser $url 1>/dev/null 2>&1\
  || sensible-browser $url 1>/dev/null 2>&1\
  || ( echo "ERR: $msg" >&2; exit 3 )
}

########################################
# View all/selected running wikis in the default browser
#
# Globals:
#   wiki_status_csv: used
#
# Arguments:
#   [keylist]: space separated list of wikis key to stop, default is stop all
#
# Requires:
#   INT: run_browser
########################################
view_wikis () {
  declare -A ports_arr # associative array ( key port) of all running wikis
  local line
  local i
  local url="http://localhost:"

# Get ports_arr=( key port )
  while IFS="," read -a line; do # line array=( key path pid port )
    [[ -n "${line[3]}" ]] && ports_arr[${line[0]}]=${line[3]}
  done <<< "$wiki_status_csv"

  [[ ${#ports_arr[@]} -eq 0 ]] && return # there si nothing to view

# View all wikis
  if [[ $# -eq 0 ]]; then
    for i in ${ports_arr[@]}; do
      url+=$i
      run_browser $url
    done
  fi

# View wikis according keylist, prevent multiple views of one key
  while (( $# > 0 )); do # args cycle
    for i in ${!ports_arr[@]}; do
      if [[ "$1" == "$i" ]]; then
        url+=${ports_arr[$i]}
        run_browser $url && unset ports_arr[$i]
      fi
    done
    shift
  done
}
########################################

########################################
# Find first free TCP port from defined range
#
# Arguments:
#   $1: name of the array of tcp ports range
#   $2: name of the array with already listening tcp ports
#
# OUTPUTS:
#   STDOUT: free port or ""
#   STDERR: message if no free port found
#
# RETURNS:
#   return 0: success
#   exit 2: no free TCP port in the range
########################################
get_free_port () {
  local -n range=$1 # referenced array of ports to select from
  local -n busy=$2  # referenced array of listening ports
  local i j
  local found_flag

  for i in "${range[@]}"; do # loop through range tcp values
    found_flag="true"
    # echo "Testing tcp: ${range[$i]}"
    for j in "${busy[@]}"; do # loop through busy tcp values
      [[ $i -eq $j ]] && found_flag="false" && break
    done
    if [[ "$found_flag" == "true" ]]; then
      echo "$i"
      return 0 # on the first occurrence of free port
    fi
  done
  echo "ERR: no free TCP port has been found in the range ${range[@]}." >&2
  exit 2 # cannot continue because no free port in the range has been found
}
########################################

########################################
# Start all/selected wikis thar are not running yet
#
# Globals:
#   wiki_status_csv: used
#
# Arguments:
#   [keylist]: of wikis to run, default is all
#
# OUTPUTS:
#   STDOUT: list of started wikis + total count
#   STDERR: if (key path) and (key port) arrays are of unequal lengths
#   STDERR: if neither ss|netstat is not installed
#
# RETURNS:
#   exit 2: if (key path) and (key port) arrays are of unequal lengths
#   exit 3: if requirements are not met
#
# Requires:
#   INT: get_free_port
#   EXT: awk, ss|netstat
########################################
start_wikis () {
  local tcp_range=( {8001..8050} ) # array of ports to select from
  local tcp_busy # array of already listening ports
  local started=0 # total started count
  local line # line array
  local wport # wiki port
  local key # wiki key
  declare -A path_arr # associative array key->path
  declare -A port_arr # associative array key->port

# Get busy tcp_busy with ss|nestat
  wport=$(ss -tln 2>/dev/null || netstat -tln 2>/dev/null)
  [[ $? -ne 0 ]] \
    && echo "ERR: required app 'ss'|'netstat' not installed." >&2 \
    && exit 3
  tcp_busy=( $(echo "$wport" \
    | awk 'NR > 1 && $4 !~ /::/ { sub(/.*:/,"",$4); print $4 }') )

# Make path_arr (key path) and port_arr (key port) for wikis available to start
  while IFS="," read -a line; do # array=( key path pid port )
    key=${line[0]}
    path_arr[$key]="${line[1]}"
    wport=$(get_free_port tcp_range tcp_busy)
    port_arr[$key]=$wport
    tcp_busy+=($wport) # after port_arr assignment make port looks like busy
  done <<< "$(echo "$wiki_status_csv" \
    | awk -F, '$2 !~ /^WNA:\s/ && $4 !~ /^[0-9]+$/')" # don't start WNA or running

# Verify for each case arrays are of equal length
  [[ ${#port_arr[@]} -ne ${#path_arr[@]} ]] \
    && echo "ERR: unexpected error." >&2 \
    && exit 2

# Start all wikis available to start in bgr
  if [[ $# -eq 0 ]]; then
    for key in ${!path_arr[@]}; do
      tiddlywiki "${path_arr[$key]}" \
        --listen port=${port_arr[$key]} &>/dev/null &
      echo "Started wiki $key on '${path_arr[$key]}' port ${port_arr[$key]}"
      sleep 0.5
      (( started+=1 ))
    done
  fi

# Start wikis according keylist in bgr, prevent multiple starts one key
  while (( $# > 0 )); do # args cycle
    key=$1
    if [[ ${path_arr[$key]} ]]; then
      tiddlywiki "${path_arr[$key]}" \
        --listen port=${port_arr[$key]} &>/dev/null &
      echo "Started wiki $key on '${path_arr[$key]}' port ${port_arr[$key]}"
      sleep 0.5
      unset path_arr[$key]
      unset port_arr[$key]
      (( started+=1 ))
    fi
    shift
  done
  echo "Started total: $started"
}
########################################

########################################
# Stop all/selected already running wikis
#
# Globals:
#   wiki_status_csv: used
#
# Arguments:
#   [keylist]: space separated list of wikis key to stop, default is stop all
#
# Outputs:
#   STDOUT: list of stopped wikis + total count
########################################
stop_wikis () {
  local killed=0 # total killed count
  declare -A pids_arr # associative array ( key pid ) of running & conf wikis
  local line
  local pid
  local i

  # Kill all running wikis (having pid) including those not configured
  if [[ $# -eq 0 ]]; then
    while IFS="," read -a line; do # line array=(key|'' path pid port)
      pid=${line[2]}
      if [[ $pid ]]; then
        kill $pid || kill -9 $pid \
          && echo "Stopped wiki ${line[0]} pid '$pid'" \
          && sleep 0.5 \
          && (( killed+=1 ))
      fi
    done <<< "$wiki_status_csv"
  fi

  # Kill configured wikis according keylist
  # and prevent multiple kills of repeating key on keylist
  if [[ $# -gt 0 ]]; then
    # Get pids_arr=( key pid ) of running & configure wikis
    while IFS="," read -a line; do # line array=( key path pid port )
      [[ ${line[0]} ]] && [[ -n "${line[2]}" ]] && pids_arr[${line[0]}]=${line[2]}
    done <<< "$wiki_status_csv"
    # Kill them according keylist
    while (( $# > 0 )); do # args cycle
      key=$1
      pid=${pids_arr[$key]}
      if [[ $pid ]]; then
        kill $pid || kill -9 $pid \
          && echo "Stopped wiki $key pid '$pid'" \
          && sleep 0.5 \
          && unset pids_arr[$key] \
          && (( killed+=1 ))
       fi
       shift
    done
  fi
  echo "Stopped total: $killed"
}
########################################


########################################
# Main
########################################
main () {
# Prepare
check_rc
source "$rcfile"
wiki_status_csv=$(mk_wiki_status)

# Read opts/args and run service functions accordingly
case $1 in
  -h | --help)
    print_help
    ;;
  -s | --status)
    print_status
    ;;
  -v | --version)
    print_version
    ;;
  start)
    shift # necessary shift to provide start with keylist
    start_wikis "$@"
    wiki_status_csv=$(mk_wiki_status) # view updated status
    print_status
    ;;
  stop)
    shift # necessary shift to provide stop with keylist
    stop_wikis "$@"
    wiki_status_csv=$(mk_wiki_status) # view updated status
    print_status
    ;;
  view)
    shift # necessary shift to provide view with keylist
    view_wikis "$@"
    ;;
  *)
    [[ -z $1 ]] || echo -e "ERR: unregognized input '$1'.\n" >&2 && print_usage
    ;;
esac
}
########################################

main "$@"