Commit 84e04ccf authored by Andrew Brooks's avatar Andrew Brooks
Browse files

dockerTools: Preprocess layers list before unpack to handle repeated layers

parent 298c543e

pkgs/build-support/docker/default.nix

+12 −3
Original line number Diff line number Diff line
@@ -229,6 +229,15 @@ rec { 
          mount /dev/${vmTools.hd} disk

          cd disk



          function dedup() {

            declare -A seen

            while read ln; do

              if [[ -z "''${seen["$ln"]:-}" ]]; then

                echo "$ln"; seen["$ln"]=1

              fi

            done

          }



          if [[ -n "$fromImage" ]]; then

            echo "Unpacking base image..."

            mkdir image
@@ -245,7 +254,8 @@ rec { 
              parentID="$(cat "image/manifest.json" | jq -r '.[0].Config | rtrimstr(".json")')"

            fi



            cat ./image/manifest.json  | jq -r '.[0].Layers | .[]' > layer-list

            # In case of repeated layers, unpack only the last occurrence of each

            cat ./image/manifest.json  | jq -r '.[0].Layers | .[]' | tac | dedup | tac > layer-list

          else

            touch layer-list

          fi
@@ -259,14 +269,13 @@ rec { 


            mkdir -p image/$extractionID/layer

            tar -C image/$extractionID/layer -xpf image/$layerTar

            rm image/$layerTar



            find image/$extractionID/layer -name ".wh.*" -exec bash -c 'name="$(basename {}|sed "s/^.wh.//")"; mknod "$(dirname {})/$name" c 0 0; rm {}' \;



            # Get the next lower directory and continue the loop.

            lowerdir=image/$extractionID/layer''${lowerdir:+:}$lowerdir

          done

          # Don't remove tarballs until all unpacked in case some are used more than once

          awk '{print "image/"$0}' layer-list | xargs rm -f



          mkdir work

          mkdir layer