detect linux OS from packagecloud.io

detect_os.sh

: '
thanks to https://packagecloud.io/
You can find a list of supported OSes and distributions on our website: https://packagecloud.io/docs#os_distro_version
'

detect_os_deb ()
{
  if [[ ( -z "${os}" ) && ( -z "${dist}" ) ]]; then
    # some systems dont have lsb-release yet have the lsb_release binary and
    # vice-versa
    if [ -e /etc/lsb-release ]; then
      . /etc/lsb-release

      if [ "${ID}" = "raspbian" ]; then
        os=${ID}
        dist=`cut --delimiter='.' -f1 /etc/debian_version`
      else
        os=${DISTRIB_ID}
        dist=${DISTRIB_CODENAME}

        if [ -z "$dist" ]; then
          dist=${DISTRIB_RELEASE}
        fi
      fi

    elif [ `which lsb_release 2>/dev/null` ]; then
      dist=`lsb_release -c | cut -f2`
      os=`lsb_release -i | cut -f2 | awk '{ print tolower($1) }'`

    elif [ -e /etc/debian_version ]; then
      # some Debians have jessie/sid in their /etc/debian_version
      # while others have '6.0.7'
      os=`cat /etc/issue | head -1 | awk '{ print tolower($1) }'`
      if grep -q '/' /etc/debian_version; then
        dist=`cut --delimiter='/' -f1 /etc/debian_version`
      else
        dist=`cut --delimiter='.' -f1 /etc/debian_version`
      fi

    else
      unknown_os
    fi
  fi

  if [ -z "$dist" ]; then
    unknown_os
  fi

  # remove whitespace from OS and dist name
  os="${os// /}"
  dist="${dist// /}"

  echo "Detected operating system as $os/$dist."
}

detect_os_rpm ()
{
  if [[ ( -z "${os}" ) && ( -z "${dist}" ) ]]; then
    if [ -e /etc/os-release ]; then
      . /etc/os-release
      os=${ID}
      if [ "${os}" = "poky" ]; then
        dist=`echo ${VERSION_ID}`
      elif [ "${os}" = "sles" ]; then
        dist=`echo ${VERSION_ID}`
      elif [ "${os}" = "opensuse" ]; then
        dist=`echo ${VERSION_ID}`
      elif [ "${os}" = "opensuse-leap" ]; then
        os=opensuse
        dist=`echo ${VERSION_ID}`
      else
        dist=`echo ${VERSION_ID} | awk -F '.' '{ print $1 }'`
      fi

    elif [ `which lsb_release 2>/dev/null` ]; then
      # get major version (e.g. '5' or '6')
      dist=`lsb_release -r | cut -f2 | awk -F '.' '{ print $1 }'`

      # get os (e.g. 'centos', 'redhatenterpriseserver', etc)
      os=`lsb_release -i | cut -f2 | awk '{ print tolower($1) }'`

    elif [ -e /etc/oracle-release ]; then
      dist=`cut -f5 --delimiter=' ' /etc/oracle-release | awk -F '.' '{ print $1 }'`
      os='ol'

    elif [ -e /etc/fedora-release ]; then
      dist=`cut -f3 --delimiter=' ' /etc/fedora-release`
      os='fedora'

    elif [ -e /etc/redhat-release ]; then
      os_hint=`cat /etc/redhat-release  | awk '{ print tolower($1) }'`
      if [ "${os_hint}" = "centos" ]; then
        dist=`cat /etc/redhat-release | awk '{ print $3 }' | awk -F '.' '{ print $1 }'`
        os='centos'
      elif [ "${os_hint}" = "scientific" ]; then
        dist=`cat /etc/redhat-release | awk '{ print $4 }' | awk -F '.' '{ print $1 }'`
        os='scientific'
      else
        dist=`cat /etc/redhat-release  | awk '{ print tolower($7) }' | cut -f1 --delimiter='.'`
        os='redhatenterpriseserver'
      fi

    else
      aws=`grep -q Amazon /etc/issue`
      if [ "$?" = "0" ]; then
        dist='6'
        os='aws'
      else
        unknown_os
      fi
    fi
  fi

  if [[ ( -z "${os}" ) || ( -z "${dist}" ) ]]; then
    unknown_os
  fi

  # remove whitespace from OS and dist name
  os="${os// /}"
  dist="${dist// /}"

  echo "Detected operating system as ${os}/${dist}."

  if [ "${dist}" = "8" ]; then
    _skip_pygpgme=1
  else
    _skip_pygpgme=0
  fi
}

unknown_os ()
{
  echo "Unfortunately, your operating system distribution and version are not supported by this script."
  echo
  echo "You can override the OS detection by setting os= and dist= prior to running this script."
  echo
  echo "For example, to force CentOS 6: os=el dist=6 ./detect_os.sh"
  echo "For example, to force Ubuntu Trusty: os=ubuntu dist=trusty ./detect_os.sh"
  echo
  exit 1
}

detect_os_deb
detect_os_rpm