check_new_release

#!/usr/bin/env bash
# @file check_new_release
# Update tap script if there is a new VKE CLI build
# @author Alister Lewis-Bowen <alister@lewis-bowen.org>

[[ -n $DEBUG ]] && set -x
set -eou pipefail

SCRIPT_PATH="$( cd "$(dirname "$0")" ; pwd -P )"
LAST_BUILD_FILE="$SCRIPT_PATH/.last_build_date"
CLI_URL=''
CMD_SHA256=''
VERBOSE='n'

help() {
    echo "Update tap script if there is a new VKE CLI build"
    echo
    echo "Usage: chec_new_release [options]"
    echo "Options:"
    echo "  -h, --help, help .... displays this help information"
    echo "  -v, --verbose ....... display informational messages"
    return 0
}

while [[ $# -gt 0 ]]; do
    case "$1" in
        -v | --verbose )      VERBOSE='y'; shift;;
        help | -h | --help )  help; exit 0;;
        * ) shift ;;
    esac
done

# Platform dependencies ------------------------------------------------------

case "$OSTYPE" in
    darwin*)  
        CMD_SHA256='shasum -a 256'
        CLI_URL="$(curl -s https://api.vke.cloud.vmware.com/v1/cli | jq -r .latest.urls.mac)"
        ;;
    linux*)
        CMD_SHA256='sha256sum'
        CLI_URL="$(curl -s https://api.vke.cloud.vmware.com/v1/cli | jq -r .latest.urls.linux64)"
        ;;
    *)  return 1;;
esac

# Helper functions -----------------------------------------------------------

get_last_modified() { 
    curl -s -I "$CLI_URL" | grep Last-Modified | sed 's/Last-Modified: //'
}

message() {
    [[ "$VERBOSE" == 'y' ]] && echo "$@"
}

# Check if we have anything to compare against -------------------------------

if [[ ! -e "$LAST_BUILD_FILE" ]]; then
    get_last_modified > "$LAST_BUILD_FILE"
    message "Storing current build date: $(cat "$LAST_BUILD_FILE")"
    exit 0
fi

# Check for build update before updating tap ---------------------------------

LAST_BUILD_DATE=$(cat "$LAST_BUILD_FILE")
TAP_SCRIPT="$SCRIPT_PATH/vke-cli.rb"
SHA256=$(grep sha256 "$TAP_SCRIPT" | cut -d'"' -f 2)
VERSION=$(grep version\  "$TAP_SCRIPT"  | cut -d'"' -f 2)

if curl -s -I --header "If-Modified-Since: $LAST_BUILD_DATE" "$CLI_URL" | grep -q '304 Not Modified'; then
    message "No build since $LAST_BUILD_DATE"
    message "  SHA256: $SHA256"
    message "  Version: $VERSION"
else
    curl -s "$CLI_URL" -o /tmp/vke && chmod 755 /tmp/vke
    SHA256_NEW=$($CMD_SHA256 /tmp/vke | cut -d' ' -f1)
    BUILD=$(/tmp/vke --version | cut -d'(' -f2 | cut -d')' -f1 | cut -d':' -f2 | sed 's/ //')
    VERSION_NEW="0.9.0.$BUILD"
    rm -fR /tmp/vke
    sed -i.tmp -e "s/$SHA256/$SHA256_NEW/g" -- "$TAP_SCRIPT" && rm "${TAP_SCRIPT}.tmp"
    sed -i.tmp -e "s/$VERSION/$VERSION_NEW/g" -- "$TAP_SCRIPT" && rm "${TAP_SCRIPT}.tmp"
    get_last_modified > "$LAST_BUILD_FILE"
    message "New build $BUILD created $(cat "$LAST_BUILD_FILE")"
    message "  SHA256: $SHA256 → $SHA256_NEW"
    message "  Version: $VERSION → $VERSION_NEW"
fi