Intelligently clean a Sonatype Nexus repository... keep the last 2 released versions of each "major.minor" artifact

cleanrepo.sh

#!/bin/bash
DRY_RUN=1
if [ "$1" != "" ]; then
  DRY_RUN="$1"
fi
MAX_VERSION=2
if [ "$2" != "" ]; then
  MAX_VERSION="$2"
fi

if [ $MAX_VERSION -lt 2 ]; then
  echo "You must keep at least 2 versions"
  exit 1
fi

total_space=0

pushd /devel/nexus/sonatype-work/nexus/storage/releases

TRASH=./.nexus/trash

metadata_files=`find . -not -path '*/\.*' -type f -name maven-metadata.xml`
for metadata_file in $metadata_files; do
  artifact_folder=`dirname $metadata_file`
  if [[ $artifact_folder != *"-setup" ]] && [[ $artifact_folder != *"-webapp" ]] && [[ $artifact_folder != *"-install" ]] && [[ $artifact_folder != *"-application-bundle" ]]; then
    continue
  fi
  minor_versions=`sed 's#.*<version>\([0-9]*\.[0-9]*\).*</version>#\1#;tx;d;:x' $metadata_file | uniq`
  for minor_version in $minor_versions; do
    inc_versions_todelete_count=`ls -l -d -v $artifact_folder/$minor_version* | wc -l`
    if [ $inc_versions_todelete_count -gt $MAX_VERSION ]; then
      echo "There are $inc_versions_todelete_count versions in $artifact_folder/$minor_version*... Need to delete old versions"

      if [ $DRY_RUN -eq 0 ]; then
        trash_artifact_folder=$TRASH${artifact_folder#"."}
        trash_artifact_folder_attr=$TRASH/.nexus/attributes${artifact_folder#"."}
        mkdir -p $trash_artifact_folder
        mkdir -p $trash_artifact_folder_attr
      fi

      for inc_version_todelete in `ls -l -d -v $artifact_folder/$minor_version* | head -n -$MAX_VERSION | awk '{print $9}'`; do
        version=`basename $inc_version_todelete`
        inc_version_todelete_attr=.nexus/attributes${inc_version_todelete#"."}
        echo "  Moving $version to trash..."

        space=`du -b -s $inc_version_todelete | awk '{print $1}'`
        total_space=$((total_space + space))
        space=`du -b -s $inc_version_todelete_attr | awk '{print $1}'`
        total_space=$((total_space + space))

        if [ $DRY_RUN -eq 0 ]; then
          mv $inc_version_todelete $trash_artifact_folder
          mv $inc_version_todelete_attr $trash_artifact_folder_attr
        fi
      done
    fi
  done
done

chown -R nexus:nexus $TRASH

popd

convert_bytes_human() {
  NUMBER=$1
  for DESIG in B K M G T P; do
   [ $NUMBER -lt 1024 ] && break
   let NUMBER=$NUMBER/1024
  done
  printf "%d%s\n" $NUMBER $DESIG
}

convert_bytes_human $total_space

For those interested, Nexus 3 version here:
https://gist.github.com/legege/1f8e7b82675fc15beae4a6d9a8640d03