auth/sample/bin/pod_wait.sh

#!/bin/bash
#
# A Script for use in Pods... Check for status files, and validate before moving on.
#
DIR="/opt/app/aaf/status"
APP=$1
shift
OTHER=$1
shift

function status {
  if [ -d "$DIR" ]; then
     echo "$@" > $DIR/$APP
  fi
}

echo $APP $OTHER

function check {
  if [ -d "$DIR" ]; then
    if [ -e "$DIR/$OTHER" ]; then
      echo "$(cat $DIR/$OTHER)"
    else 
      echo "$DIR/$OTHER does not exist"
    fi
  else 
    echo "$DIR does not exist"
  fi
}

echo "App $APP is waiting to start until $OTHER is ready"
status "waiting for $OTHER"

n=0
while [ $n -lt 40  ]; do 
   rv="$(check)"
   echo "$OTHER is $rv"
   if [ "$rv" = "ready" ]; then
     # This is critical.  Until status is literally "ready" in the status directory, no processes will start
     status ready
     echo "Starting $@"
     n=10000
   else 
     (( ++n )) 
     echo "Sleep 10 (iteration $n)"
     sleep 10
   fi
done

eval "$@"