This is a Bash script for fetching artifacts from Nexus via the command line

fetch_artifact_from_nexus.sh

#!/usr/bin/env bash

########################################################################################################
# This is a utility script to fetch artifacts from a Nexus server. It is based on an example           #
# from Sonartype Nexus: http://blog.sonatype.com/2011/01/downloading-artifacts-from-nexus-with-bash/   #
########################################################################################################

set -e

REST_PATH=/service/local
ART_REDIR=/artifact/maven/redirect

usage()
{
cat <<EOF
usage: $0 options
This script will fetch an artifact from a Nexus server using the Nexus REST redirect service.
OPTIONS:
   -h      Show this message
   -v      Verbose (Default: 0)
   -n      Nexus base URL including protocol (Required)
   -i      GAV coordinate groupId:artifactId:version (Required)
   -c      Artifact Classifier (Default: empty)
   -p      Artifact Packaging (Default: jar)
EOF
}

NEXUS_BASE=
GROUP_ID=
ARTIFACT_ID=
VERSION=
CLASSIFIER=""
PACKAGING="jar"
REPO=
VERBOSE=0

while getopts "hvn:i:c:p:" OPTION
do
     case $OPTION in
         h)
             usage
             exit 1
             ;;
         n)
             NEXUS_BASE=$OPTARG
             ;;
         i)
             OIFS=$IFS
             IFS=":"
             GAV_COORD=( $OPTARG )
             GROUP_ID=${GAV_COORD[0]}
             ARTIFACT_ID=${GAV_COORD[1]}
             VERSION=${GAV_COORD[2]}
             IFS=$OIFS
             ;;
         c)
             CLASSIFIER=$OPTARG
             ;;
         p)
             PACKAGING=$OPTARG
             ;;
         v)
             VERBOSE=1
             ;;
         ?)
             usage
             exit
             ;;
     esac
done

if [ ${VERBOSE} == 1 ]; then
  set -x
fi

if [[ -z $NEXUS_BASE ]] || [[ -z $GROUP_ID ]] || [[ -z $ARTIFACT_ID ]] || [[ -z $VERSION ]]
then
     echo "BAD ARGUMENTS: Either Nexus URL, groupId, artifactId, or version was not supplied" >&2
     usage
     exit 1
fi

if [[ "${VERSION}" =~ .*SNAPSHOT ]]
then
    : ${REPO:="snapshots"}
else
    : ${REPO:="releases"}
fi

REDIRECT_URL=${NEXUS_BASE}${REST_PATH}${ART_REDIR}

PARAM_KEYS=( g a v r p c )
PARAM_VALUES=( $GROUP_ID $ARTIFACT_ID $VERSION $REPO $PACKAGING $CLASSIFIER )
PARAMS=""
for index in ${!PARAM_KEYS[*]}
do
  if [[ ${PARAM_VALUES[$index]} != "" ]]
  then
    PARAMS="${PARAMS}${PARAM_KEYS[$index]}=${PARAM_VALUES[$index]}&"
  fi
done

REDIRECT_URL="${REDIRECT_URL}?${PARAMS}"
OUTPUT_FILENAME="output.tmp"

echo "Fetching Artifact from $REDIRECT_URL" >&2
RESPONSE_CODE=`curl -sS -L -o ${OUTPUT_FILENAME} -w "%{http_code}" ${REDIRECT_URL}`

if [ ! ${RESPONSE_CODE} == "200" ]; then
  cat ${OUTPUT_FILENAME}
  rm -f ${OUTPUT_FILENAME}
  exit 1
else
  mv ${OUTPUT_FILENAME} "${ARTIFACT_ID}.${PACKAGING}"
fi