Shell script to replace variables docker-compose.yml

replace-var

#!/bin/bash
set -eu
 
main() {
  local args=("$@")
  local inFile=$(pwd)/docker-compose.yml
  local outFile=$(pwd)/$1
    
  if [[ $# -lt 2 ]]; then
  	usage
  fi
 
  cp $inFile $outFile
  for ((i=1; i<${#args[@]}; i++)); do
  	local pair=(${args[i]//=/ }) # tokenize by =
  	pair[1]="${pair[1]//\//\\/}" # escape paths
  	sed -i -e "s/\${${pair[0]}}/${pair[1]}/g" $outFile
    echo "Replacing: $i  \${${pair[0]}} with ${pair[1]}"
  done
}
 
usage(){
	echo "replace-var 1.0"
	echo "Substitutes variables of type \${VAR1} in docker-compose.yml and writes them into the file defined as the first argument"
	echo "Usage: replace-var result.yml VAR1=value1 VAR2=value2 ..."
}
 
main $@