Compressed Multipart Form Data POST with CURL

curl-multipart-gz.sh

#!/usr/bin/env bash

set -eufo pipefail

declare -A form_parts

function usage() {
    cat <<END >&2
USAGE: $0 [-F key=value] [-F key=@file] [curl-opts] [-v|-h]
        -F key=value      # curl post key=value
        -h|?              # usage
        -v                # verbose

eg,
     $0 -F connection_id=${users_db_id} -F upsert=false -F send_completion_email=false -F users=@users.json
END
    exit $1
}

function build_multipart() {
  local -n b=$1
  local -n parts=$2
  for key in "${!parts[@]}"; do
    printf "%s\r\n" "--${b}"
    local value="${parts[$key]}"
    if [[ $value == @* ]]; then
      local file="${value#?}"
      [[ ! -f "${file}" ]] && { echo >&2 "ERROR: file not found: ${file}"; exit 3; }
      printf "Content-Disposition: form-data; name=\"%s\"; filename=\"%s\"\r\n" "${key}" "$(basename "${file}")"
      #printf "Content-Type: %s\r\n\r\n" "$(file --mime-type -b "${file}")"
      printf "Content-Type: application/octet-stream\r\n\r\n"
      cat "${file}"
    else
      printf "Content-Disposition: form-data; name=\"%s\"\r\n\r\n" "${key}"
      echo -n "${value}"
    fi
    printf "\r\n"
  done
  printf "%s\r\n" "--${b}--"
}

function get_boundary() {
  echo $RANDOM | md5sum | head -c 32
}

function content_type_header() {
  echo "Content-Type: multipart/form-data; boundary=$1"
}

while getopts "F:hv?" opt; do
  case ${opt} in
  F) form_parts[${OPTARG%%=*}]=${OPTARG#*=} ;;
  ?) usage 0 ;;
  esac
done

readonly boundary=$(get_boundary)

export AUTH0_DOMAIN_URL=$(echo "${access_token}" | awk -F. '{print $2}' | base64 -di 2>/dev/null | jq -r '.iss')

# --trace-ascii trace-multipart.txt

build_multipart boundary form_parts | gzip | curl \
   -H "$(content_type_header "${boundary}")" \
   -H "Authorization: Bearer ${access_token}" \
   -H "Content-Encoding: gzip" \
   --url "${AUTH0_DOMAIN_URL}api/v2/jobs/users-imports" \
   --data-binary @-