Generate deps graph from multistage Dockerfile

dockerfile-deps-graph-gen.sh

#!/usr/bin/env bash

function extract_key_value() {
  egrep -o "$1[:=]['\"[:alnum:]\-]+" | egrep -o "['\"[:alnum:]\-]+$" | egrep -o "[[:alnum:]\-]+"
}

function docker_multistage_deps() {
  cat Dockerfile \
    | grep -i 'FROM ' \
    | grep -i ' AS ' \
    | awk '{print $2 " --> " $4}'
}

function docker_copy_between_images_deps() {
  cat Dockerfile \
    | grep -i 'from' \
    | while read line 
      do
        if [[ $line == COPY* ]]
        then
          source=`echo $line | extract_key_value from`
          target=`echo $context | awk '{print $4}'`
          
          echo "$source -.- $target "
        fi

        if [[ $line == FROM* ]]
        then
          context=$line
        fi

      done
}

echo '``` mermaid'
echo "graph LR"
echo ""
docker_multistage_deps
echo ""
docker_copy_between_images_deps
echo '```'