Short script to upload a file to a GCS bucket and print its public URL

fup

#!/usr/bin/env bash
prog="$(basename "$0")"

## Defaults

# : ${FUP_BUCKET:=YOUR-BUCKET}
# : ${FUP_URL_PREFIX:=https://CUSTOM-URL/}
: ${FUP_PAR_UPLOAD_THRESHOLD:=100M}
: ${FUP_URL_PREFIX:=https://storage.googleapis.com/${FUP_BUCKET}/}


## Support functions

usage() {
  cat <<EOF
Usage: ${prog} [OPTIONS] [--] [FILE...]

Upload a file to a Google Cloud Storage bucket with a SHA2 base64
directory prefix. If file is '-' (or /dev/stdin), or no file is given,
fup will read stdin to a temporary file and upload it as a 'stdin' file.

You can set the FUP_BUCKET and FUP_SHASUM environment variables to
declare a default bucket (-b) and shasum program (-c). FUP_SHASUM
defaults to the first available of shasum, sha224sum, or sha3-224sum.

Other environment variables are listed in the options below.

Options:
-b <BUCKET> Set the bucket to copy files to. Can have a path prefix.
            Required if FUP_BUCKET is not set. May not contain
            a trailing slash.
-c <PROG>   Program command-line for computing a checksum from a file.
            Must output one line in shasum format.
            Defaults to a sha224sum program if FUP_SHASUM is not set.
-t <THR>    Sets the parallel upload threshold used by gsutil.
            Defaults to 100M if FUP_PAR_UPLOAD_THRESHOLD is not set.
-u <URL>    Set the URL prefix printed by $prog.
            Defaults to the Google storage bucket's URL if
            FUP_URL_PREFIX is not set.
-p          Copy file URL(s) to clipboard.
-P          Do not copy file URL(s) to clipboard (default).
            Overrides previous uses of -p.
-v          Emit gsutil progress output.
-V          Do not emit gsuitl progress output (default).
            Overrides previous uses of -v.
-h, --help  Print this usage text.
EOF
  exit 2
}

FATAL() {
  local ec="$1"
  shift
  echo 'ERR' "$@" 1>&2
  exit "$ec"
}

bsum() {
  if ! sum="$($FUP_SHASUM "$@")"; then
    return 1
  fi
  echo -n "$sum" |
    awk '{print $1}' |
    xxd -r -p | base64 |
    tr /+ _- | tr -d = |
    sed -e 's/^\(.\)\(.\)/\1\/\2\//'
}

upload() {
  local desc="$1"
  local file="${desc%%:*}"
  local istmp=0
  # Special case standard input
  if [[ "$file" = - ]] || [[ "$file" = /dev/stdin ]]; then
    istmp=1
    if ! file="$(mktemp)"; then
      FATAL 1 "Cannot create temporary file for standard input"
    fi
    cat > "$file"
    desc=stdin
  fi
  if [[ ! -f "$file" ]]; then
    FATAL 1 "Cannot upload non-file: $file"
  fi
  local name="$(basename "${desc#*:}")"
  if ! sum="$(bsum "$file" | awk '{print $1}')"; then
    FATAL 1 "Unable to get the checksum of $name"
  fi
  local path="${sum}/$name"
  local gspath="gs://$FUP_BUCKET/$path"
  if ! gsutil $quiet -o "GSUtil:parallel_composite_upload_threshold=$FUP_PAR_UPLOAD_THRESHOLD" cp -- "$file" "$gspath" 1>&2; then
    FATAL 1 "Unable to upload $name"
  fi
  if ! gsutil $quiet acl ch -u AllUsers:R "$gspath" 1>&2; then
    if [[ "$istemp" = 1 ]] && [[ -f "$file" ]]; then
      rm "$file"
    fi
    FATAL 1 "Unable to set ACL on $gspath to publicly readable"
  fi
  if [[ "$istemp" = 1 ]] && [[ -f "$file" ]]; then
    rm "$file"
  fi
  printf '%s%s%s' "$FUP_URL_PREFIX" "$path"
}


## Main

if [[ -z "$(command -v gsutil)" ]]; then
	FATAL 1 $'gsutil not found in PATH. Please install the Google Cloud SDK:\n\n\thttps://cloud.google.com/sdk/install'
fi

tmpout=/dev/null
pasteprefix=
paste=0
quiet=-q

while [ $# -gt 0 ]; do
  case "$1" in
  -b)   FUP_BUCKET="$2"; shift;;
  -b=*) FUP_BUCKET="${1#-b=}";;
  -b?*) FUP_BUCKET="${1#-b}";;

  -c)   FUP_SHASUM="$2"; shift;;
  -c=*) FUP_SHASUM="${1#-c=}";;
  -c?*) FUP_SHASUM="${1#-c}";;

  -t)   FUP_PAR_UPLOAD_THRESHOLD="$2"; shift;;
  -t=*) FUP_PAR_UPLOAD_THRESHOLD="${1#-t=}";;
  -t?*) FUP_PAR_UPLOAD_THRESHOLD="${1#-t}";;

  -u)   FUP_URL_PREFIX="$2"; shift;;
  -u=*) FUP_URL_PREFIX="${1#-u=}";;
  -u?*) FUP_URL_PREFIX="${1#-u}";;

  # Toggles
  -p) paste=1;;
  -P) paste=0;;

  -v) quiet=;;
  -V) quiet=-q;;

  -h|--help) usage;;

  --) shift; break;;
  *) break;;
  esac
  shift
done

if [[ -z "$FUP_BUCKET" ]]; then
  FATAL 2 'FUP_BUCKET is not set -- it must be set to a GCS bucket name'
elif [[ "$FUP_BUCKET" = */ ]]; then
  FATAL 2 'FUP_BUCKET may not contain a trailing slash'
fi

# Set default shasum
if [ -z "$FUP_SHASUM" ]; then
  if [ -n "$(command -v sha224sum)" ]; then
    FUP_SHASUM='sha224sum'
  elif [ -n "$(command -v gsha224sum)" ]; then
    FUP_SHASUM='gsha224sum'
  elif [ -n "$(command -v shasum)" ]; then
    FUP_SHASUM='shasum -a224'
  elif [ -n "$(command -v sha3-224sum)" ]; then
    # Just because we want something with some length here
    FUP_SHASUM=sha3-224sum
  else
    FATAL 1 'None of sha224sum, shasum, nor sha3-224sum are available'
  fi
fi

if [[ $# -eq 0 ]]; then
  set -- -
fi

if [[ "$1" = -p ]]; then
  shift
  paste=1
fi

if [[ $paste -eq 1 ]]; then
  if ! tmpout="$(mktemp)"; then
    FATAL 1 "Cannot create temporary URLs file"
  fi
  trap 'rm "$tmpout"' EXIT
fi

for file; do
  if ! url="$(upload "$file")"; then
    FATAL 1 "Upload failed: $file"
  fi

  echo "$url"
  if [[ $paste -eq 1 ]]; then
    printf "%s%s" "$pasteprefix" "$url" >>"$tmpout"
    pasteprefix=$'\n'
  fi
done

if [[ $paste -eq 1 ]]; then
  # TODO: Add checks for x11 clipboard managers
  <"$tmpout" pbcopy
fi