bootstrap

#!/usr/bin/env bash

set -euo pipefail

# ——— Functions definition —————————————————————————————————————————————————————

function bootstrap::cloneBranch() {
    local -r repository="$1"
    local -r branch="$2"
    local -r directory="$3"

    command -v git &>/dev/null || bootstrap::installGit || return $?

    printf 'Checking if git repository has an installer for your distribution\n' >&2
    # get all branches in one call. This prevent from doing a second request if we can't find the branch
    allBranches="$( git ls-remote --quiet --heads "$repository" | sed -E -e 's/^.*refs\/heads\///' | grep -vE '^main$' )"

    if ! echo "$allBranches" | grep -q -E "^$branch\$"
    then
        printf $'\e''[38;5;1m' >&2
        printf 'Your current distribution version is not supported (yet?).\n' >&2
        printf $'\e''[39m' >&2
        printf 'detected distribution: %s\n' "$branch" >&2
        printf 'Supported distributions\n' >&2
        printf -- '-----------------------\n' >&2

        printf '%s\n' "$allBranches" | while IFS= read -r branchFound
        do
            printf ' * %s\n' "$branchFound" >&2
        done

        printf 'Maybe you can clone one of them?\n' >&2
        printf '$ git clone --quiet --single-branch --depth=1 --branch "\e[4m<distribution>\e[24m" "%s" "%s"\n' "$repository" "$directory" >&2

        return 1
    fi

    printf >&2 'Found! Cloning repository...\n'
    git clone --quiet --single-branch --depth=1 --branch "$branch" "$repository" "$directory"
}
declare -rf bootstrap::cloneBranch

function bootstrap::detectOperatingSystem() {
    if [[ $OSTYPE != linux-gnu* ]]
    then
        printf 'Your operating system is not supported.\n' >&2

        return 1
    fi

    # lsb_release for easiest, complete, cross-distro discovery
    if command -v lsb_release &>/dev/null
    then
        lsb_dist="$( lsb_release -i -s )"
        DIST_DISTRIBUTION="${lsb_dist,,}"  # Convert to lowercase
        # Assuming version is numeric therefore doesn't need lowercasing
        DIST_VERSION="$( lsb_release -r -s )"
    # release file methods
    elif [[ -e /etc/redhat-release ]]
    then
        # RedHat family distributions all have this file
        # sed to make it conform to what `lsb_release -d` would produce if it were available
        file_dist=$( sed 's/ release [0-9].*$//; s/ linux$//i; s/ linux //ig; s/ //g' /etc/redhat-release )
        DIST_DISTRIBUTION="${file_dist,,}"
        DIST_VERSION=$( sed 's/^.* release \([0-9][0-9.]*\).*$/\1/' /etc/redhat-release )
    elif [[ -e /etc/lsb-release ]]
    then
        # Convert to lowercase
        DIST_DISTRIBUTION="$( source /etc/lsb-release ; echo "${DISTRIB_ID,,}" )"
        # Assuming version is numeric therefore doesn't need lowercasing
        DIST_VERSION="$( source /etc/lsb-release ; echo "$DISTRIB_RELEASE" )"
    elif [[ -e /etc/debian_version ]]
    then
        # Can only be Debian (Ubuntu caught by /etc/lsb-release, above)
        DIST_DISTRIBUTION=debian
        DIST_VERSION="$( cat /etc/debian_version )"
    # systemd's os-release (might not have full version number)
    elif [[ -e /etc/os-release ]]
    then
        DIST_DISTRIBUTION="$( source /etc/os-release ; echo "$ID" )"
        DIST_VERSION="$( source /etc/os-release ; echo "$VERSION_ID" )"
    elif [[ -e /usr/lib/os-release ]]
    then
        DIST_DISTRIBUTION="$( source /usr/lib/os-release; echo "$ID" )"
        DIST_VERSION="$( source /usr/lib/os-release; echo "$VERSION_ID" )"
    else
        case "$OSTYPE" in
            linux-gnu*)
                printf 'Your operating system is not supported.\n' >&2
                ;;
            darwin*)
                printf 'OSX is not supported.\n' >&2
                ;;
            cygwin|msys|win32)
                printf 'Windows is not supported.\n' >&2
                ;;
            freebsd*)
                printf 'freebsd is not supported.\n' >&2
                ;;
        esac

        return 1
    fi

    if [[ $DIST_DISTRIBUTION = 'ubuntu' ]]
    then
        # Every release of Ubuntu is a major release
        DIST_VERSION_MAJOR="$DIST_VERSION"
    else
        # Everything up to first '.' is major version
        DIST_VERSION_MAJOR="${DIST_VERSION%%.*}"
    fi

    export DIST_DISTRIBUTION DIST_VERSION_MAJOR
}
declare -rf bootstrap::detectOperatingSystem

function bootstrap::help() {
    printf '
\e[1mNAME\e[22m
\t%s - clone repository and run install script on detected distribution branch

\e[1mSYNOPSIS\e[22m
\t\e[38;5;2m%s\e[39m [\e[38;5;3m--help\e[39m] [\e[38;5;3m--dir \e[4m<directory>\e[24;39m] [\e[38;5;3m--repository \e[4m<repository>\e[24;39m]

\e[1mOPTIONS\e[22m
       \e[38;5;3m--help\e[39m
           Display this help message.

       \e[38;5;3m--dir \e[4m<directory>\e[24;39m
           Use this directory as location to clone repository. Creates a
           temporary directory by default.

       \e[38;5;3m--repository \e[4m<repository>\e[24;39m
           The (possibly remote) \e[4;38;5;3m<repository>\e[24;39m to clone
           from.

       \e[38;5;3m--stats, --no-stats\e[39m
           Enable or disable running stats before and after software
           installation to see all the files that have been modified/created.
           This option is passed to the distribution installer.
           Default: enabled

       \e[38;5;3m--default\e[39m
           Use default settings and reduce the number of interactions required
           to install. This option disable the creation of workspaces.
           This option is passed to the distribution installer.
' "${0##*/}" "${0##*/}"
}
declare -rf bootstrap::help

function bootstrap::installGit() {
    printf 'Installing git\n' >&2

    if command -v apt-get &>/dev/null
    then
        sudo apt-get -qq -y --update --no-install-recommends install git ca-certificates
    elif command -v dnf &>/dev/null
    then
        sudo dnf -q -y --refresh install git ca-certificates
    elif command -v yum &>/dev/null
    then
        sudo yum -q -y install git ca-certificates
    else
        printf 'Unable to install git - could not determine the package manager of your distribution.\n' >&2

        return 1
    fi
}
declare -rf bootstrap::installGit

function bootstrap::main() {
    local branch
    local directory=
    local repository=
    local -a installScriptOptions=()

    while [[ $# -gt 0 ]]
    do
        case "$1" in
            --directory|--repository) # only check for presence of a second argument here
                if [[ $# -eq 1 ]]
                then
                    printf '%s: missing parameter for option %s\n' "${0##*/}" "$1" >&2
                    bootstrap::usage >&2
                    return 2
                fi
                ;;&
            -h|--help|-\?) bootstrap::help >&2; return 0;;
            --stats|--no-stats|--default) installScriptOptions+=("$1"); shift;;
            --directory)
                directory="$2"
                shift 2
                ;;
            --repository)
                repository="$2"
                shift 2
                ;;
            -*) printf '%s: unknown option %s\n' "${0##*/}" "$1" >&2; bootstrap::usage >&2; return 2;;
            *)  printf '%s: unknown argument %s\n' "${0##*/}" "$1" >&2; bootstrap::usage >&2; return 2;;
        esac
    done

    [[ -n "$directory" ]] || directory="$( mktemp -d )"
    [[ -n "$repository" ]] || repository='https://github.com/juliendufresne/system-post-install.git'

    bootstrap::detectOperatingSystem || return 1
    branch="$DIST_DISTRIBUTION-$DIST_VERSION_MAJOR"

    bootstrap::cloneBranch "$repository" "$branch" "$directory"

    [[ $( pwd ) == "$directory" ]] || cd "$directory" || return 1

    [[ $( git branch --show-current ) == "$branch" ]] || git checkout "$branch"

    if [[ ! -x install ]]
    then
        if [[ -f install ]]
        then
            printf "File '%s/install' is not executable.\n" "$directory" >&2
        else
            printf "File '%s/install' does not exist.\n" "$directory" >&2
        fi

        return 1
    fi

    printf 'Running install.\n' >&2
    ./install "${installScriptOptions[@]}"
}
declare -rf bootstrap::main

function bootstrap::usage() {
    printf 'usage: \e[38;5;2m%s\e[39m' "${0##*/}"
    printf ' [\e[38;5;3m--help\e[39m]'
    printf ' [\e[38;5;3m--dir \e[4m<directory>\e[24;39m]'
    printf ' [\e[38;5;3m--repository \e[4m<repository>\e[24;39m]\n'
    printf ' [\e[38;5;3m--(no-)stats\e[39m]'
    printf ' [\e[38;5;3m--default\e[39m]'
}
declare -rf bootstrap::usage

# ——— Script execution —————————————————————————————————————————————————————————

bootstrap::main "$@"