gow

#!/bin/sh
# ----------------------------------------------------------------------------
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you 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.
# ----------------------------------------------------------------------------

# ----------------------------------------------------------------------------
# GO Start Up Batch script
#
#
# Optional ENV vars
# -----------------
#   GOROOT=/app/go - if go already installed locally
#   GOW_VERBOSE=true - to make it verbose
#   GOW_REPOURL=https://dl.google.com/go - default REPOURL
# ----------------------------------------------------------------------------

# OS specific support.  $var _must_ be set to either true or false.
cygwin=false;
darwin=false;
mingw=false
os="linux";
arch="amd64";
extension="tar.gz"

case "`uname`" in
  CYGWIN*) cygwin=true;os="windows";extension="zip";;
  MINGW*) mingw=true;os="windows";extension="zip";;
  Darwin*) darwin=true;os="darwin";;
esac
case "`uname -m`" in
  x86_64) arch="amd64";;
  x86) arch="386";;
esac


if [ -z "$GOW_REPOURL" ]
then
  GOW_REPOURL="https://dl.google.com/go"
fi


# traverses directory structure from process work directory to filesystem root
# first directory with .go subdirectory is considered project base directory
find_go_basedir() {
  if [ -z "$1" ]
  then
    echo "Path not specified to find_maven_basedir"
    return 1
  fi

  basedir="$1"
  wdir="$1"
  while [ "$wdir" != '/' ] ; do
    if [ -d "$wdir"/.go ] ; then
      basedir=$wdir
      break
    fi
    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
    if [ -d "${wdir}" ]; then
      wdir=`cd "$wdir/.."; pwd`
    fi
    # end of workaround
  done
  echo "${basedir}"
}

# concatenates all lines of a file
concat_lines() {
  if [ -f "$1" ]; then
    echo "$(tr -s '\n' ' ' < "$1")"
  fi
}

BASE_DIR=`find_go_basedir "$(pwd)"`
if [ -z "$BASE_DIR" ]; then
  exit 1;
fi

##########################################################################################
# Extension to allow automatically downloading GO
# This allows using the go-wrapper in projects that prohibit checking in binary data.
##########################################################################################

goVersionUrl="https://go.dev/dl/"
goWrapperPath="$BASE_DIR/.go/wrapper"
goWrapperProperties="$goWrapperPath/go-wrapper.properties"
goInstallPath="$goWrapperPath/go"
goTmpPath="$goWrapperPath/tmp"
goWrapperDate="$goInstallPath/go.date"
goVersionPath="$goTmpPath/go.version"
goZipPath="$goTmpPath/go.$extension"

if $cygwin; then
  goWrapperPath=`cygpath --path --windows "$goWrapperPath"`
  goWrapperProperties=`cygpath --path --windows "$goWrapperProperties"`
  goInstallPath=`cygpath --path --windows "$goInstallPath"`
  goTmpPath=`cygpath --path --windows "$goTmpPath"`
  goWrapperDate=`cygpath --path --windows "$goWrapperDate"`
  goVersionPath=`cygpath --path --windows "$goVersionPath"`
  goZipPath=`cygpath --path --windows "$goZipPath"`
fi

retrieve_version() {
  if [ -z "$1" ]
  then
    echo "Path not specified to retrieve_version"
    return 1
  fi
  go_version=`cat "$1" | grep toggleVisible | awk -F'"' 'NR==1{print substr($4,3)}'`
  echo "${go_version}"
}

unpack_archive(){
  if [ "$extension" == "zip" ]; then
    unzip "$goZipPath" -d "$goWrapperPath"
  else
    tar -C "$goWrapperPath" -zxvf "$goZipPath"
  fi
  if [ -f "$goVersionPath" ]; then
    rm "$goVersionPath"
  fi
  date > "$goWrapperDate"
}

get_local_go() {
    if [ -f "$goWrapperDate" ]; then
        if [ "$GOW_VERBOSE" = true ]; then
          echo "Found $goInstallPath"
        fi
    elif [ -f "$goZipPath" ]; then
        if [ "$GOW_VERBOSE" = true ]; then
          echo "Found $goZipPath"
          unpack_archive
        fi
    else
        if [ "$GOW_VERBOSE" = true ]; then
          echo "Couldn't find $goInstallPath, downloading it ..."
        fi
        mkdir -p "$goTmpPath"
        if [ -f "$goWrapperProperties" ]; then
            while IFS="=" read key value  || [ "$key" ]; do
              case "$key" in (distributionUrl) goUrl=`echo "$value" | sed 's/ *$//g'`; break ;;
                             (goVersion) go_version=$value; break ;;
              esac
            done < "$goWrapperProperties"
        fi

        if command -v wget > /dev/null; then
            if [ "$GOW_VERBOSE" = true ]; then
              echo "Found wget ... using wget"
            fi
            if [ -z "$goUrl" ]; then
              if [ -z "$go_version" ]; then
                if [ ! -f "$goVersionPath" ]; then
                    if [ -z "$GOW_USERNAME" ] || [ -z "$GOW_PASSWORD" ]; then
                        wget "$goVersionUrl" -O "$goVersionPath"
                    else
                        wget --http-user=$GOW_USERNAME --http-password=$GOW_PASSWORD "$goVersionUrl" -O "$goVersionPath"
                    fi
                fi
                go_version=`retrieve_version "$goVersionPath"`
              fi
              goUrl="$GOW_REPOURL/go$go_version.$os-$arch.$extension"
            fi
            if [ "$GOW_VERBOSE" = true ]; then
              echo "Downloading from: $goUrl"
            fi
            if [ -z "$GOW_USERNAME" ] || [ -z "$GOW_PASSWORD" ]; then
                wget "$goUrl" -O "$goZipPath"
            else
                wget --http-user=$GOW_USERNAME --http-password=$GOW_PASSWORD "$goUrl" -O "$goZipPath"
            fi
            unpack_archive
        elif command -v curl > /dev/null; then
            if [ "$GOW_VERBOSE" = true ]; then
              echo "Found curl ... using curl"
            fi
            if [ -z "$goUrl" ]; then
              if [ -z "$go_version" ]; then
                if [ ! -f "$goVersionPath" ]; then
                    if [ -z "$GOW_USERNAME" ] || [ -z "$GOW_PASSWORD" ]; then
                        curl -o "$goVersionPath" "$goVersionUrl" -f -s
                    else
                        curl --user $GOW_USERNAME:$GOW_PASSWORD -o "$goVersionPath" "$goVersionUrl" -f -s
                    fi
                fi
                go_version=`retrieve_version "$goVersionPath"`
              fi
              goUrl="$GOW_REPOURL/go$go_version.$os-$arch.$extension"
            fi
            if [ "$GOW_VERBOSE" = true ]; then
              echo "Downloading from: $goUrl"
            fi
            if [ -z "$GOW_USERNAME" ] || [ -z "$GOW_PASSWORD" ]; then
                curl -o "$goZipPath" "$goUrl" -f
            else
                curl --user $GOW_USERNAME:$GOW_PASSWORD -o "$goZipPath" "$goUrl" -f
            fi
            unpack_archive
        else
            echo "TODO: default downloader"
        fi
    fi
}
##########################################################################################
# End of extension
##########################################################################################

if [ -z "$GOROOT" ]; then
    get_local_go
    GOROOT="$goInstallPath"
fi

# Set GOPATH in case there is none 
if [ -z "$GOPATH" ]; then
    GOPATH=`$GOROOT/bin/go env GOPATH`
fi

# For Cygwin, switch paths to Windows format before running go
if $cygwin; then
  [ -n "$GOROOT" ] &&
    GOROOT=`cygpath --path --windows "$GOROOT"`
  [ -n "$GOPATH" ] &&
    GOPATH=`cygpath --path --windows "$GOPATH"`
fi

# Provide a "standardized" way to retrieve the CLI args that will
# work with both Windows and non-Windows executions.
GO_CMD_LINE_ARGS="$@"
export GO_CMD_LINE_ARGS

# Export Go Variables for downstream executions
export GOROOT
export GOPATH
export PATH="$GOROOT/bin:$GOPATH/bin:$PATH"

if [ "$1" = "printenv" ]; then 
  echo "export GOROOT=\"$GOROOT\""
  echo "export GOPATH=\"$GOPATH\""
  echo "export PATH=\"\$GOROOT/bin:\$GOPATH/bin:\$PATH\""
  echo ''
  echo '# Run this command to configure your shell:'
  echo '# eval "$(./gow printenv)"'
else
  exec "$GOROOT/bin/go" "$@"
fi