oras

#!/usr/bin/env bash

# Copyright The Hedgehog Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# The install script is based off of the Helm v3 install script:
# https://github.com/helm/helm/blob/main/scripts/get-helm-3

: ${BINARY_NAME:="oras"}
: ${USE_SUDO:="true"}
: ${DEBUG:="false"}
: ${INSTALL_DIR:="/usr/local/bin"}

HAS_CURL="$(type "curl" &> /dev/null && echo true || echo false)"
HAS_WGET="$(type "wget" &> /dev/null && echo true || echo false)"

# initArch discovers the architecture for this system.
initArch() {
  ARCH=$(uname -m)
  case $ARCH in
    armv5*) ARCH="armv5";;
    armv6*) ARCH="armv6";;
    armv7*) ARCH="arm";;
    aarch64) ARCH="arm64";;
    x86) ARCH="386";;
    x86_64) ARCH="amd64";;
    i686) ARCH="386";;
    i386) ARCH="386";;
  esac
}

# initOS discovers the operating system for this system.
initOS() {
  OS=$(echo `uname`|tr '[:upper:]' '[:lower:]')

  case "$OS" in
    # Minimalist GNU for Windows
    mingw*|cygwin*) OS='windows';;
  esac
}

# runs the given command as root (detects if we are root already)
runAsRoot() {
  if [ $EUID -ne 0 -a "$USE_SUDO" = "true" ]; then
    sudo "${@}"
  else
    "${@}"
  fi
}

# verifySupported checks that the os/arch combination is supported for
# binary builds, as well whether or not necessary tools are present.
verifySupported() {
  local supported="darwin-amd64\ndarwin-arm64\nlinux-amd64\nlinux-arm64"
  if ! echo "${supported}" | grep -q "${OS}-${ARCH}"; then
    echo "No prebuilt binary for ${OS}-${ARCH}."
    echo "To build from source, go to https://github.com/oras-project/oras"
    exit 1
  fi

  if [ "${HAS_CURL}" != "true" ] && [ "${HAS_WGET}" != "true" ]; then
    echo "Either curl or wget is required"
    exit 1
  fi
}

findLatestVersion() {
    local latest_release_url="https://api.github.com/repos/oras-project/oras/releases/latest"
    local latest_release_response=""
    if [ "${HAS_CURL}" == "true" ]; then
      latest_release_response=$( curl -L --silent --show-error --fail "$latest_release_url" 2>&1 || true )
    elif [ "${HAS_WGET}" == "true" ]; then
      latest_release_response=$( wget "$latest_release_url" -O - 2>&1 || true )
    fi
    TAG=$( echo "$latest_release_response" | grep '"tag_name"' | sed -E 's/.*"(v[0-9\.]+)".*/\1/g' | cut -c 2- )
    if [ "x$TAG" == "x" ]; then
      printf "Could not retrieve the latest release tag information from %s: %s\n" "${latest_release_url}" "${latest_release_response}"
      exit 1
    fi
}

downloadFile() {
  DIST="oras_${TAG}_${OS}_${ARCH}.tar.gz"
  DOWNLOAD_URL="https://github.com/oras-project/oras/releases/download/v$TAG/$DIST"
  TMP_ROOT="$(mktemp -dt oras-XXXXXX)"
  TMP_FILE="$TMP_ROOT/$DIST"
  echo "Downloading $DOWNLOAD_URL"
  if [ "${HAS_CURL}" == "true" ]; then
    curl -SsL "$DOWNLOAD_URL" -o "$TMP_FILE"
  elif [ "${HAS_WGET}" == "true" ]; then
    wget -q -O "$TMP_FILE" "$DOWNLOAD_URL"
  fi
}

installFile() {
  TMP="$TMP_ROOT/$BINARY_NAME"
  mkdir -p "$TMP"
  tar xf "$TMP_FILE" -C "$TMP"
  TMP_BIN="$TMP/oras"
  echo "Preparing to install $BINARY_NAME into ${INSTALL_DIR}"
  runAsRoot cp "$TMP_BIN" "$INSTALL_DIR/$BINARY_NAME"
  echo "$BINARY_NAME installed into $INSTALL_DIR/$BINARY_NAME"
}

# fail_trap is executed if an error occurs.
fail_trap() {
  result=$?
  if [ "$result" != "0" ]; then
    if [[ -n "$INPUT_ARGUMENTS" ]]; then
      echo "Failed to install $BINARY_NAME with the arguments provided: $INPUT_ARGUMENTS"
      help
    else
      echo "Failed to install $BINARY_NAME"
    fi
  fi
  cleanup
  exit $result
}

# cleanup temporary files to avoid https://github.com/helm/helm/issues/2977
cleanup() {
  if [[ -d "${TMP_ROOT:-}" ]]; then
    rm -rf "$TMP_ROOT"
  fi
}

# Execution

#Stop execution on any error
trap "fail_trap" EXIT
set -e
set -o pipefail

# Set debug if desired
if [ "${DEBUG}" == "true" ]; then
  set -x
fi

initArch
initOS
verifySupported
findLatestVersion
downloadFile
installFile
cleanup