fetch

#!/usr/bin/env bash

#################################################
### Fetch Hashi Product By Version from internet
#################################################

#Set Script Name variable
SCRIPT=`basename ${BASH_SOURCE[0]}`

DEFAULT_PLATFORM=$(uname -s -m | tr '[:upper:] ' '[:lower:]_' | sed -e 's/_aarch64$/_arm64/g' -e 's/_x86_64$/_amd64/g')

### # functions
function usage () {
  local ec=0
  local l_MSG=$1
  if [ "${l_MSG}" != "" ]; then
    echo "Usage Error: $l_MSG"
    echo ''
    ec=1
  fi
  echo "Usage: ${SCRIPT} -p <string>"
  echo '  where <string> specifies the product name'
  echo ''
  echo 'Recognized optional command line arguments'
  echo '-v <string>  -- specifies the target version.  Defaults to latest stable version.'
  echo "-a <string>  -- specifies the target architecture.  Defaults to \`${DEFAULT_PLATFORM}\`"
  echo '-e           -- download enterprise versions'
  echo '-n           -- do not create a symlink in /usr/local/bin'
  exit 1
}

## TODO: implement latest using `https://releases.hashicorp.com/«product»/index.json`
function getLatest () {
  local FILTER="-v"
  if [ "${ENT}" == "true" ]; then
    FILTER=""
  fi

  local LATEST_VERSION=$(curl -q -s https://releases.hashicorp.com/$1/ |\
    tr '<>' ' ' |\
    awk "/href=\\\"\\/$1/{ print \$3}" |\
    awk -F"_" '{print $2}' |\
    grep ${FILTER} "+ent" |\
    head -n 1
  )
  echo "${LATEST_VERSION}"
}

function maybeCreateSymlink () {
if [ -z "${NOCREATESYMLINK}" ]
then
  if [ -L "/usr/local/bin/${PRODUCT}" ]
  then
    if ! rm -rf "/usr/local/bin/${PRODUCT}"; then
	    echo "Unable to remove existing symlink. Trying with sudo..."
	    sudo rm -rf "/usr/local/bin/${PRODUCT}"
    fi
  fi
  if ! ln -s "/opt/${PRODUCT}/bin/${PRODUCT}-v${VERSION}" "/usr/local/bin/${PRODUCT}"; then
	  echo "Unable to create symlink in /usr/local/bin. Trying with sudo..."
	  sudo ln -s "/opt/${PRODUCT}/bin/${PRODUCT}-v${VERSION}" "/usr/local/bin/${PRODUCT}"
  fi
fi

}

### # starting main

### check number of command line arguments
NUMARGS=$#
if [ $NUMARGS -eq 0 ]; then
  usage 'No command line arguments specified'
fi

### Start getopts code ###
# Parse command line flags
# If an option should be followed by an argument, it should be followed by a ":".
# The leading ":" suppresses error messages from
# getopts. This is required to get my unrecognized option code to work.
while getopts :ndep:v:a: FLAG; do
  case $FLAG in
    p) # set option "p" specifying the product
      PRODUCT=$OPTARG
      ;;
    v) # set option "v"
      VERSION=$OPTARG
      ;;
    a) # set option "a"
      ARCHITECTURE=$OPTARG
      ;;
    n) # set option "n"
      NOCREATESYMLINK=0
      ;;
    e) # set option "e"
      ENT=true
      ;;
    d) # set option "d"
      DRYRUN=true
      ;;
    *) # invalid command line arguments
      usage "Invalid command line argument $OPTARG"
      ;;
  esac
done

#shift $((OPTIND-1))  # This tells getopts to move on to the next argument.

### # check that Product is not empty
if [ -z "${PRODUCT}" ]
then
  usage 'Product name must be specified using option -p <string>'
fi

if [ -z "${ARCHITECTURE}" ]
then
  ARCHITECTURE="${DEFAULT_PLATFORM}"
fi

if [ -z "${VERSION}" ]
then
  ## this is conditional because there is some effort in getting the latest version
  VERSION=$(getLatest ${PRODUCT})
fi

echo "Fetching ${PRODUCT} v${VERSION} for ${ARCHITECTURE}..."
URL="https://releases.hashicorp.com/${PRODUCT}/${VERSION}/${PRODUCT}_${VERSION}_${ARCHITECTURE}.zip"
if [ "${DRYRUN}" == "true" ]; then
  echo "  URL: ${URL}"
  echo ""
  echo "Skipping download in dry run mode."
  exit 0
fi

TMPDIR=`mktemp -d /tmp/fetch.XXXXXXXXXX` || exit 1
pushd ${TMPDIR} > /dev/null
if ! mkdir -p /opt/${PRODUCT}/bin; then
	echo "Unable to create /opt/${PRODUCT}/bin. Trying with sudo..."
	sudo mkdir -p /opt/${PRODUCT}/bin
fi
wget -q ${URL} -O ${PRODUCT}.zip
unzip -q ${PRODUCT}.zip
if ! mv ${PRODUCT} /opt/${PRODUCT}/bin/${PRODUCT}-v${VERSION}; then
	echo "Unable to move downloaded file to /opt/${PRODUCT}/bin/${PRODUCT}-v${VERSION}. Trying with sudo..."
	sudo mv ${PRODUCT} /opt/${PRODUCT}/bin/${PRODUCT}-v${VERSION}
fi
popd > /dev/null
rm -rf ${TMPDIR}
maybeCreateSymlink