install-binary.sh

#!/bin/bash

# Shamelessly copied from https://github.com/technosophos/helm-template

PROJECT_NAME="helm-diff"
PROJECT_GH="databus23/$PROJECT_NAME"

: ${HELM_PLUGIN_PATH:="$(helm home --debug=false)/plugins/helm-diff"}

# Convert the HELM_PLUGIN_PATH to unix if cygpath is
# available. This is the case when using MSYS2 or Cygwin
# on Windows where helm returns a Windows path but we
# need a Unix path

if type cygpath > /dev/null 2>&1; then
  HELM_PLUGIN_PATH=$(cygpath -u $HELM_PLUGIN_PATH)
fi

if [[ $SKIP_BIN_INSTALL == "1" ]]; then
  echo "Skipping binary install"
  exit
fi

# initArch discovers the architecture for this system.
initArch() {
  ARCH=$(uname -m)
  case $ARCH in
    armv5*) ARCH="armv5";;
    armv6*) ARCH="armv6";;
    armv7*) ARCH="armv7";;
    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
    # Msys support
    msys*) OS='windows';;
    # Minimalist GNU for Windows
    mingw*) OS='windows';;
    darwin) OS='macos';;
  esac
}

# verifySupported checks that the os/arch combination is supported for
# binary builds.
verifySupported() {
  local supported="linux-amd64\nmacos-amd64\nwindows-amd64"
  if ! echo "${supported}" | grep -q "${OS}-${ARCH}"; then
    echo "No prebuild binary for ${OS}-${ARCH}."
    exit 1
  fi

  if ! type "curl" > /dev/null && ! type "wget" > /dev/null; then
    echo "Either curl or wget is required"
    exit 1
  fi
}

# getDownloadURL checks the latest available version.
getDownloadURL() {
  local version=$(git -C $HELM_PLUGIN_PATH describe --tags --exact-match 2>/dev/null)
  if [ -n "$version" ]; then
    DOWNLOAD_URL="https://github.com/$PROJECT_GH/releases/download/$version/helm-diff-$OS.tgz"
  else
    # Use the GitHub API to find the download url for this project.
    local url="https://api.github.com/repos/$PROJECT_GH/releases/latest"
    if type "curl" > /dev/null; then
      DOWNLOAD_URL=$(curl -s $url | grep $OS | awk '/\"browser_download_url\":/{gsub( /[,\"]/,"", $2); print $2}')
    elif type "wget" > /dev/null; then
      DOWNLOAD_URL=$(wget -q -O - $url | grep $OS | awk '/\"browser_download_url\":/{gsub( /[,\"]/,"", $2); print $2}')
    fi
  fi
}

# downloadFile downloads the latest binary package and also the checksum
# for that binary.
downloadFile() {
  PLUGIN_TMP_FILE="/tmp/${PROJECT_NAME}.tgz"
  echo "Downloading $DOWNLOAD_URL"
  if type "curl" > /dev/null; then
    curl -L "$DOWNLOAD_URL" -o "$PLUGIN_TMP_FILE"
  elif type "wget" > /dev/null; then
    wget -q -O "$PLUGIN_TMP_FILE" "$DOWNLOAD_URL"
  fi
}

# installFile verifies the SHA256 for the file, then unpacks and
# installs it.
installFile() {
  HELM_TMP="/tmp/$PROJECT_NAME"
  mkdir -p "$HELM_TMP"
  tar xf "$PLUGIN_TMP_FILE" -C "$HELM_TMP"
  HELM_TMP_BIN="$HELM_TMP/diff/bin/diff"
  echo "Preparing to install into ${HELM_PLUGIN_PATH}"
  mkdir -p "$HELM_PLUGIN_PATH/bin"
  cp "$HELM_TMP_BIN" "$HELM_PLUGIN_PATH/bin"
}

# fail_trap is executed if an error occurs.
fail_trap() {
  result=$?
  if [ "$result" != "0" ]; then
    echo "Failed to install $PROJECT_NAME"
    echo "\tFor support, go to https://github.com/databus23/helm-diff."
  fi
  exit $result
}

# testVersion tests the installed client to make sure it is working.
testVersion() {
  set +e
  echo "$PROJECT_NAME installed into $HELM_PLUGIN_PATH/$PROJECT_NAME"
  $HELM_PLUGIN_PATH/bin/diff -h
  set -e
}

# Execution

#Stop execution on any error
trap "fail_trap" EXIT
set -e
initArch
initOS
verifySupported
getDownloadURL
downloadFile
installFile
testVersion