Extracting docker services to be run from a complex docker-compose command

extractdockerservices.sh

#!/bin/bash
function getLinkedServices(){
  IFS=
  serviceToCheck=$1
  serviceDefintion=$(echo $finalDockerFile | grep "^\s\s$serviceToCheck:" -A $lengthOfDockerFile -m 1)
  nextServiceLine=$(echo $serviceDefintion | tail -n +2 | grep "^\s\s[a-zA-Z0-9]\+:" -m 1 -n | awk '{print $1}')
  if [ "$nextServiceLine" != "" ]
  then
      nextServiceLine=${nextServiceLine:0:-1}
  else
      nextServiceLine=$lengthOfDockerFile
  fi  
  serviceDefintion=$(echo $serviceDefintion | head -n $nextServiceLine)
  serviceLinks=$(echo $serviceDefintion | grep "^\s\s\s\slinks:" -A $nextServiceLine | tail -n +2 | grep "^\s\s\s\s[a-zA-Z]\+:" -B $nextServiceLine -m 1 | head -n -1)
  serviceLinks=${serviceLinks//\- /}
  IFS=$OLDIFS

  for serviceLink in $serviceLinks
  do
      indexToCheckIfServiceIsAliased=$(echo "$serviceLink" | awk '{print index($serviceLink, ":")}')
      if [ "$indexToCheckIfServiceIsAliased" != 0 ]
      then
          serviceLink=${serviceLink:0:$((indexToCheckIfServiceIsAliased-1))}
      fi
      serviceExistsCheck=$(echo ${servicesBeingStartedUp[@]} | grep "$serviceLink")
      if [ "$serviceExistsCheck" == "" ]
      then
          servicesBeingStartedUp+=($serviceLink)
          getLinkedServices $serviceLink
      fi
  done    
}

#run this script with something like the following command
#./checkclones "docker-compose -f docker-compose.yml -f .docker-compose-servicea.yml -f .docker-compose-service-b.yml" "some-service"
#where some-service is a service defined within one of those docker-compose files. 
dockerComposeCommandWithFiles=$1
servicesToUp=$2
servicesToIterateThrough=$(echo ${servicesToUp:1} | tr " " "\n")
OLDIFS=$IFS
IFS=
finalDockerFile=$(eval ${dockerComposeCommandWithFiles} config)
lengthOfDockerFile=$(echo $finalDockerFile | wc -l)
servicesBeingStartedUp=()
for service in $servicesToIterateThrough
do
    getLinkedServices $service
done
echo ${servicesBeingStartedUp[@]}