startup

#!/bin/bash

# If you are looking for docs on this script, consult https://github.com/jshook/simple-startup
# or, preferably, just run ./startup

# functions
containsElement () {
  local e
  for e in "${@:2}"; do [[ "$e" == "$1" ]] && return 0; done
  return 1
}

# locate non-relative script dir
MAIN_SCRIPT_BASEDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

# normalize path to script
MAIN_SCRIPT="${MAIN_SCRIPT_BASEDIR}/"$( basename $0 )
EXECUTION_DIR=$(dirname ${MAIN_SCRIPT})


# locate .startup directory
MAIN_SCRIPT_DIRNAME=$(dirname $MAIN_SCRIPT)
if [ "${MAIN_SCRIPT_DIRNAME}" = ".startup" ]
then export COMPONENTS_DIRNAME="${MAIN_SCRIPT_DIRNAME}"
else export COMPONENTS_DIRNAME="${MAIN_SCRIPT_DIRNAME}/.startup"
fi

# sanity check for only one startup script
if [ -f "${COMPONENTS_DIRNAME}/startup" -a -f "${COMPONENTS_DIRNAME}/../startup" ]
then
 printf "ERROR: You must choose where to put your one and only 'startup' script.\n"
 printf "You have one in both locations below:\n%s\n%s\n" "${COMPONENTS_DIRNAME}/startup" "${COMPONENTS_DIRNAME}/../startup"
 exit 2
fi

if [ ! -d "${COMPONENTS_DIRNAME}" ]
then
 printf "ERROR: component scripts directory '${COMPONENTS_DIRNAME}' does not exist.\n"
 exit 2
fi

##
## Initialize known component scripts array
##
component_scriptnames_ary=()

SCRIPT_DATA=$(cd $COMPONENTS_DIRNAME; /bin/ls)
while read -r line
do
 if [ "$line" = "startup.order" ] ; then continue ; fi
 if [ "$line" = "startup" ] ; then continue ; fi
 if [ ! -x "${COMPONENTS_DIRNAME}/$line" ] ; then continue ; fi
 if [ -z "$line" ] ; then continue; fi
 component_scriptnames_ary+=("$line")
done <<< "$SCRIPT_DATA"
#printf "DEBUG: component_scriptname: %s\n" "${component_scriptnames_ary[@]}" 1>&2

##
## Initialize ordered components array
##
component_order_ary=()

export ORDER_FILE="${COMPONENTS_DIRNAME}/startup.order"
if [ -f "${ORDER_FILE}" ]
then
 # printf "DEBUG: loading order file: %s\n" "${ORDER_FILE}" 1>&2
 ORDER_DATA=$(cat ${ORDER_FILE})
 while read -r line
 do
  if [ "$line" = "startup.order" ] ; then continue ; fi
  if [ "$line" = "startup" ] ; then continue ; fi
#  if [ "${line:0:1}" = "3" ] ; then line= ${line#\#}; fi
  component_order_ary+=("$line")
  line=${line#\#}
  COMPONENT_SCRIPT="${COMPONENTS_DIRNAME}/$line"
  if [ ! -x "${COMPONENT_SCRIPT}" ]
  then
   printf "ERROR: component startup script '${COMPONENT_SCRIPT}' is not executable or it is missing.\n";
   printf "ERROR: (it was referenced in the startup.order file in ${COMPONENTS_DIRNAME} )\n";
   exit 2
  fi
 done <<< "${ORDER_DATA}"

  # verify that all named components found in script form
  # exist in the startup.order file
 for component_scriptname in "${component_scriptnames_ary[@]}"
 do
#  printf "checking %s for ordering membership.\n" "$component_scriptname" 1>&2
  if ! containsElement "${component_scriptname}" "${component_order_ary[@]}" && ! containsElement "#${component_scriptname}" "${component_order_ary[@]}"
  then
   printf "ERROR: There is a startup.order file, but script '${component_scriptname}' is not listed in it.\n"
   exit 2
  fi
 done
else
 component_order_ary=("${component_scriptnames_ary[@]}")
fi
#printf "DEBUG: component_order: %s\n" "${component_order_ary[@]}" 1>&2

# warn if no component scripts found
if [ "${#component_order_ary[@]}" -eq 0 ]
then
 printf "ERROR: There are no executable scripts in ${COMPONENTS_DIRNAME}\n";
 exit 2
fi

if [ ! -f "${ORDER_FILE}" ]
then
 printf "# WARNING: Component order is based on filenames.\n" 1>&2
 printf "# WARNING: Consider adding a startup.order file to control order of startup.\n" 1>&2
fi

##
## Initialized selected components array
##
selected_components_ary=()
# printf "DEBUG: arg:[%s]\n" $* 1>&2
if [ "all" = "$1" ]
then
 printf "# INFO: selecting all components\n"; 1>&2
 selected_components_ary=("${component_order_ary[@]}")
elif [ ! -z "$1" ]
then
 printf "# INFO: selecting specific components: $*\n"; 1>&2
 selected_components_ary=( "$@" )
 #do selected_components_ary+=("$line")
else
 printf "INFO: You must select from the following available components, or specify 'all':\n" 1>&2
 printf "%s\n" "${component_order_ary[@]}"
 exit 0
fi
#printf "DEBUG: selected_component: %s\n" "${selected_components_ary[@]}" 1>&2

for selected in "${selected_components_ary[@]}"
do
 if ! containsElement "${selected}" "${component_order_ary[@]}" && ! containsElement "#${selected}" "${component_order_ary[@]}"
 then
  printf "%s was specified, but no such component could be found.\n" "${selected}"
  exit 2
 fi
done

ordered_components_ary=()
for component in "${component_order_ary[@]}"
do
 component=${component#\#}
 if containsElement "${component}" "${selected_components_ary[@]}"
 then ordered_components_ary+=("${component}")
 else
  printf "# INFO: component '%s' is being skipped\n" "${component}" 1>&2
 fi
done

#printf "component_order_ary: %s\n" "${component_order_ary[@]}" 1>&2
#printf "ordered_components_ary: %s\n" "${ordered_components_ary[@]}" 1>&2

# execute components in order
for selected in "${ordered_components_ary[@]}"
do
 if containsElement "${selected}" "${component_order_ary[@]}" || containsElement "#${selected}" "${component_order_ary[@]}"
 then
  FULL_SCRIPT_PATH="${COMPONENTS_DIRNAME}/${selected}"
  printf "# INFO: executing: %s\n" "${selected}"
  export PROJECT_DIRECTORY=$(dirname ${COMPONENTS_DIRNAME})
  export SELECTED_COMPONENTS="${ordered_components_ary[@]}"
  export CURRENT_COMPONENT="${selected}"
  export COMPONENT_SCRIPT="${FULL_SCRIPT_PATH}"

  ( cd ${EXECUTION_DIR} && bash ${FULL_SCRIPT_PATH})
  last_status=$?
  if [[ last_status -ne 0 ]]
  then
   printf "ERROR: script %s failed with status: %s\n" "${FULL_SCRIPT_PATH}" "${last_status}"
  fi
 else
  printf "ERROR component '%s'  was not found in ${COMPONENTS_DIRNAME}\n" "${selected}"
  exit 2;
 fi
done