#!/bin/sh

#####################################################################
#
# Copyright (C) NGINX, Inc.
#
# Author:  NGINX Unit Team, F5 Inc.
# Version: 0.0.1
# Date:    2022-05-05
#
# This script will configure the repositories for NGINX Unit on Ubuntu,
# Debian, RedHat, CentOS, Oracle Linux, Amazon Linux, Fedora.
# It must be run as root.
#
# Note: curl and awk are required by this script, so the script checks to make
# sure they are installed.
#
#####################################################################

export LC_ALL=C

checkOSPrereqs () {

    if ! command -v curl > /dev/null 2>&1
    then
        echo "Error: curl not found in PATH.  It must be installed to run this script."
        exit 1
    fi

    if ! command -v awk > /dev/null 2>&1
    then
        echo "Error: awk not found in PATH.  It must be installed to run this script."
        exit 1
    fi

    return 0
}

#####################################################################
# Function getOS
#
# Getting the OS is not the same on all distributions.  First, we use
# uname to find out if we are running on Linux or FreeBSD. For all the
# supported versions of Debian and Ubuntu, we expect to find the
# /etc/os-release file which has multiple lines with name-value pairs
# from which we can get the OS name and version. For RedHat and its
# variants, the os-release file may or may not exist, depending on the
# version.  If it doesn't, then we look for the release package and
# get the OS and version from the package name. For FreeBSD, we use the
# "uname -rs" command.
#
# A string is written to stdout with three values separated by ":":
#    OS
#    OS Name
#    OS Version
#
# If none of these files was found, an empty string is written.
#
# Return: 0 for success, 1 for error
#####################################################################
getOS () {

    os=""
    osName=""
    osVersion=""

    LC_ALL=C

    os=$(uname | tr '[:upper:]' '[:lower:]')

    if [ "$os" != "linux" ] && [ "$os" != "freebsd" ]; then
        echoErr "Error: Operating system is not Linux or FreeBSD, can't proceed"
        echo "On macOS, try 'brew install nginx/unit/unit'"
        echo
        return 1
    fi

    if [ "$os" = "linux" ]; then
        if [ -f "$osRelease" ]; then
            # The value for the ID and VERSION_ID may or may not be in quotes
            osName=$( grep "^ID=" "$osRelease" | sed s/\"//g | awk -F= '{ print $2 }')
            osVersion=$(grep "^VERSION_ID=" "$osRelease" | sed s/\"//g | awk -F= '{ print $2 }')
        else
            # rhel or centos 6.*
            if rpm -q redhat-release-server >/dev/null 2>&1; then
                osName=rhel
                osVersion=$(rpm -q redhat-release-server |sed 's/.*-//' | awk -F. '{print $1"."$2;}')
            elif rpm -q centos-release >/dev/null 2>&1; then
                osName=centos
                osVersion=$(rpm -q centos-release | sed 's/centos-release-//' | sed 's/\..*//' | awk -F- '{print $1"."$2;}')
            else
                echoErr "Error: Unable to determine the operating system and version, or the OS is not supported"
                echo
                return 1
            fi
        fi
    else
        osName=$os
        osVersion=$(uname -rs | awk -F '[ -]' '{print $2}')
        if [ -z "$osVersion" ]; then
            echoErr "Unable to get the FreeBSD version"
            echo
            return 1
        fi
    fi

    # Force osName to lowercase
    osName=$(echo "$osName" | tr '[:upper:]' '[:lower:]')
    echoDebug "getOS: os=$os osName=$osName osVersion=$osVersion"
    echo "$os:$osName:$osVersion"

    return 0
}


installDebian () {

    echoDebug "Install on Debian"

    curl --output /usr/share/keyrings/nginx-keyring.gpg https://unit.nginx.org/keys/nginx-keyring.gpg

    apt install -y apt-transport-https lsb-release ca-certificates

    printf "deb [signed-by=/usr/share/keyrings/nginx-keyring.gpg] https://packages.nginx.org/unit/debian/ %s unit\n" "$(lsb_release -cs)" | tee /etc/apt/sources.list.d/unit.list
    printf "deb-src [signed-by=/usr/share/keyrings/nginx-keyring.gpg] https://packages.nginx.org/unit/debian/ %s unit\n" "$(lsb_release -cs)" | tee -a /etc/apt/sources.list.d/unit.list

    apt update

    return 0
}

installUbuntu () {

    echoDebug "Install on Ubuntu"

    curl --output /usr/share/keyrings/nginx-keyring.gpg https://unit.nginx.org/keys/nginx-keyring.gpg

    apt install -y apt-transport-https lsb-release ca-certificates

    printf "deb [signed-by=/usr/share/keyrings/nginx-keyring.gpg] https://packages.nginx.org/unit/ubuntu/ %s unit\n" "$(lsb_release -cs)" | tee /etc/apt/sources.list.d/unit.list
    printf "deb-src [signed-by=/usr/share/keyrings/nginx-keyring.gpg] https://packages.nginx.org/unit/ubuntu/ %s unit\n" "$(lsb_release -cs)" | tee -a /etc/apt/sources.list.d/unit.list

    apt update

    return 0
}

installRedHat () {

    echoDebug "Install on RedHat/CentOS/Oracle"

    case "$osVersion" in
        6|6.*|7|7.*|8|8.*)
            cat << __EOF__ > /etc/yum.repos.d/unit.repo
[unit]
name=unit repo
baseurl=https://packages.nginx.org/unit/rhel/\$releasever/\$basearch/
gpgcheck=0
enabled=1
__EOF__
            ;;
        *)
            echo "Unsupported $osName version: $osVersion"
            exit 1
            ;;
    esac

    yum makecache

    return 0
}

installAmazon () {

    echoDebug "Install on Amazon"

    case "$osVersion" in
        2)
            cat << __EOF__ > /etc/yum.repos.d/unit.repo
[unit]
name=unit repo
baseurl=https://packages.nginx.org/unit/amzn2/\$releasever/\$basearch/
gpgcheck=0
enabled=1
__EOF__
         ;;
        *)
            cat << __EOF__ > /etc/yum.repos.d/unit.repo
[unit]
name=unit repo
baseurl=https://packages.nginx.org/unit/amzn/\$releasever/\$basearch/
gpgcheck=0
enabled=1
__EOF__
         ;;
    esac

    yum makecache

    return 0
}

installFedora () {

    echoDebug "Install on Fedora"

    cat << __EOF__ > /etc/yum.repos.d/unit.repo
[unit]
name=unit repo
baseurl=https://packages.nginx.org/unit/fedora/\$releasever/\$basearch/
gpgcheck=0
enabled=1
__EOF__

    dnf makecache

    return 0
}


am_i_root() {

    USERID=$(id -u)
    if [ 0 -ne "$USERID" ]; then
        echoErr "This script requires root privileges to run; now exiting."
        exit 1
    fi

    return 0
}

echoErr () {

    echo "$*" 1>&2;
}

echoDebug () {

    if [ "$debug" -eq 1 ]; then
        echo "$@" 1>&2;
    fi
}

main() {
debug=0 # If set to 1, debug message will be displayed

checkOSPrereqs

# The name and location of the files that will be used to get Linux
# release info
osRelease="/etc/os-release"

os="" # Will be "linux" or "freebsd"
osName="" # Will be "ubuntu", "debian", "rhel",
          # "centos", "suse", "amzn", or "freebsd"
osVersion=""

am_i_root

echo "This script will setup repositories for NGINX Unit"

# Check the OS
osNameVersion=$(getOS)
if [ -z "$osNameVersion" ]; then
    echoErr "Error getting the operating system information"
    exit 1
fi

# Break out the OS, name, and version
os=$(echo "$osNameVersion" | awk -F: '{print $1}')
osName=$(echo "$osNameVersion" | awk -F: '{print $2}')
osVersion=$(echo "$osNameVersion" | awk -F: '{print $3}')

# Call the appropriate installation function
case "$osName" in
    debian)
        installDebian
        ;;
    ubuntu)
        installUbuntu
        ;;
    rhel)
        installRedHat
        ;;
    centos)
        installRedHat
        ;;
    ol)
        installRedHat
        ;;
    amzn)
        installAmazon
        ;;
    fedora)
        installFedora
        ;;
    *)
        echo "$osName is not supported"
        exit 1
        ;;
esac

echo
echo "All done - NGINX Unit repositories for "$osName" "$osVersion" are set up"
echo "Further steps: https://unit.nginx.org/installation/#official-packages"

}

main

exit 0