Sync-IcingaRepository

#!/bin/bash
#
# Icinga custom repository synchronisation for Linux
#
#  Argument list matches powershell command
#  except for the "-Latest" option which downloads only
#  most recent packages in order to keep the local repo
#  small and reduce download traffic
#
#   Sync-IcingaRepository
#    -Name 'Icinga Stable Local'
#    -Path './var/www'
#    -RemotePath 'https://monitoring.example.org/repo'
#    -Source 'https://packages.icinga.com/IcingaForWindows/stable/ifw.repo.json';
#   [-Latest] 
#
# required dependencies:
#  curl, jq

trap "exit 1" TERM
export MYPID=$$

TMP="/tmp/"
JQ="/usr/bin/jq -r"

REPONAME=""
LOCALSOURCE=""
REMOTESOURCE=""
SOURCEREPO=""
REPOJSON=""
FULL="true"

usage()
{
    echo "Sync-IcingaRepository \\"
    echo "  -Name 'Icinga Stable Local' \\"
    echo "  -Path '/var/www' \\"
    echo "  -RemotePath 'https://monitoring.example.org/repo' \\"
    echo "  -Source 'https://packages.icinga.com/IcingaForWindows/stable/ifw.repo.json' \\"
    echo " [-Latest]"
    kill -s TERM $MYPID
}

check_arg()
{
    if [ "${2#-}" != "${2}" -o -z "$2" ] ; then
        echo "ERROR: missing argument for ${1}"
        usage
    fi
}

while [ "$#" -gt 0 ] ; do
    case "$1" in
            -Name|-name|--Name|--name|-n)
                check_arg $1 $2
                REPONAME=$2
                shift
                ;;
            -Path|-path|--Path|--path|-p)
                check_arg $1 $2
                LOCALSOURCE=$2
                shift
                ;;
            -RemotePath|-remotepath|--RemotePath|--remotepath|-r)
                check_arg $1 $2
                REMOTESOURCE=$2
                shift
                ;;
            -Source|-source|--Source|--source|-s)
                check_arg $1 $2
                SOURCEREPO=${2%/*}
                REPOJSON=${2##*/}
                shift
                ;;
            -Latest|-latest|--Latest|--latest|-l)
                FULL=""
                ;;
            *)
                echo "ERROR: unknown option ${1}"
                usage
                ;;
        esac
        shift
done

if [ -z "${REPONAME}" -o -z "${LOCALSOURCE}" -o -z "${REMOTESOURCE}" -o -z "${SOURCEREPO}" -o -z "${REPOJSON}" ] ; then
    echo "ERROR: missing argument(s)"
    usage
fi

# download current repo JSON to temp location
REMOTEREPOFILE="$(mktemp ${TMP}/icinga_repo.XXXXXXXXX)" || exit 1
curl -s "${SOURCEREPO}/${REPOJSON}" -o "${REMOTEREPOFILE}"

# check if remote repo file is more recent than local repo file
LOCALREPOFILE="${LOCALSOURCE}/${REPOJSON}"
if [ -f "${LOCALREPOFILE}" ] ; then
    LOCALREPODATE=$(${JQ} '.Info.Updated' "${LOCALREPOFILE}" | awk -F' |/' '{printf "%s-%s-%s %s",$1,$2,$3,$4}')
    REMOTEREPODATE=$(${JQ} '.Info.Updated' "${REMOTEREPOFILE}" | awk -F' |/' '{printf "%s-%s-%s %s",$1,$2,$3,$4}')
    if [ $(date -d "${LOCALREPODATE}" +%s) -lt $(date -d "${REMOTEREPODATE}" +%s) ] || [ -z "${LOCALREPODATE}" ] ; then
        echo "repo needs updating"
    else
        echo "repo didn't change"
        rm -f "${REMOTEREPOFILE}"
        exit 0
    fi
else
    echo "repo needs creating"
fi

# create target directory if it doesn't exist
if ! [ -d "${LOCALSOURCE}" ] ; then
    mkdir -p "${LOCALSOURCE}"
fi

CURRENTDATE=$(date +"%Y/%m/%d %H:%M:%S")

if [ -n "${FULL}" ] ; then
    # if script is runs without "-Latest" argument then do a complete repo sync
    ${JQ} --arg Name "${REPONAME}" --arg LocalSource "${LOCALSOURCE}" --arg RemoteSource "${REMOTESOURCE}" --arg Created "${CURRENTDATE}" --arg Updated "${CURRENTDATE}" \
        '{ "Info": (.Info | .Name=$Name | .LocalSource=$LocalSource | .RemoteSource=$RemoteSource | .Created=$Created | .Updated=$Updated), "Packages": (.Packages) }' \
        "${REMOTEREPOFILE}" > "${LOCALREPOFILE}"
else
    # otherwise only download the highest version of each package
    ${JQ} --arg Name "${REPONAME}" --arg LocalSource "${LOCALSOURCE}" --arg RemoteSource "${REMOTESOURCE}" --arg Created "${CURRENTDATE}" --arg Updated "${CURRENTDATE}" \
        '{ "Info": (.Info | .Name=$Name | .LocalSource=$LocalSource | .RemoteSource=$RemoteSource | .Created=$Created | .Updated=$Updated), "Packages": (.Packages | to_entries | map({ (.key): .value | group_by(.key, .Architecture) | map(sort_by(.Version | split(".") | map(tonumber))[-1]) }) | add ) }' \
        "${REMOTEREPOFILE}" > "${LOCALREPOFILE}"
fi
rm -f "${REMOTEREPOFILE}"

# keep track of all files belonging to the repository
FILELIST="${LOCALREPOFILE}"

# check if new files need to be downloaded
for REPOFILE in $(${JQ} '.Packages[] | .[] | "\(.Hash)#\(.Location)"' "${LOCALREPOFILE}") ; do
    FILE=${REPOFILE#*#}
    FILE=${FILE//\\/\/}
    HASH=${REPOFILE%#*}

    FILELIST="${FILELIST} ${LOCALSOURCE}/${FILE}"

    # if file exists
    if [ -f "${LOCALSOURCE}/${FILE}" ] ; then
        # compare repo file hash with sha256sum of already downloaded file
        if [ $(sha256sum "${LOCALSOURCE}/${FILE}" | cut -d' ' -f1 | tr '[:lower:]' '[:upper:]') = "${HASH}" ] ; then
            echo "${FILE} didn't change"
            continue
        else
            echo "${FILE} changed"
        fi
    else
            echo "${FILE} dosn't exist"
    fi

    # create package directories if necessary
    SUBDIR=${FILE%/*}
    if ! [ -d "${LOCALSOURCE}/${SUBDIR}" ] ; then
        mkdir -p "${LOCALSOURCE}/${SUBDIR}"
    fi

    # download package file
    curl -s "${SOURCEREPO}/${FILE}" -o "${LOCALSOURCE}/${FILE}" 
done

# cleanup files that are not referenced by repo json
for DELFILE in $(find ${LOCALSOURCE} -type f) ; do
    if [[ $FILELIST != *"${DELFILE}"* ]] ; then
        echo "deleting unreferenced ${DELFILE}"
        rm -f "${DELFILE}"
    fi
done