gistfile1.txt

#!/bin/bash -ex

replace_template_entries() {
  
  MAP=$1
  REPLACEMENT_TAG=$2
  ACTION=$3

  TOOLCHAIN_DOCKERFILE="/tmp/testsetup"

  echo "MAP=$MAP, REPLACEMENT_TAG=$REPLACEMENT_TAG, ACTION=$ACTION"

  for PAIR in $MAP
  do
    SRC=$(echo $PAIR | cut -f1 -d=)
    DEST=$(echo $PAIR | cut -f2 -d=)
    sed -i.bak  "/$REPLACEMENT_TAG/i \\
$ACTION $SRC $DEST" $TOOLCHAIN_DOCKERFILE
  done

  sed -i.bak "s#$REPLACEMENT_TAG##g" $TOOLCHAIN_DOCKERFILE
}