nmctool

#!/usr/bin/env bash

is_sourced(){ [[ "$0" != "$BASH_SOURCE" ]]; }
msg(){ echo -e "$@" 1>&2; }
err(){ msg $'\033[00;31m'"ERROR: $@"$'\033[00m'; }
die(){ err "$@"; is_sourced || exit 1 && false; }


set_keyboard(){
    local kb="${1:?Missing argument: <keyboard-layout>}";
    #sudo sed -ri "/XKBLAYOUT/ s/=.*$/=\"$kb\"/" /etc/default/keyboard;
    #sudo setupcon -v
    sudo raspi-config nonint do_configure_keyboard ${kb}
}
declare -fx set_keyboard

nopasswd_sudo(){
    local user="${1:-$SUDO_USER}"
    [[ -n "$user" ]] || { die "Usage: $0 USERNAME" || return 1; } 
    id "$user" &>/dev/null || { die "User '$user' does not exist!" || return 1; }
    msg "Adding NOPASSWD:ALL for user '$user' to sudoers file"
    echo "$user ALL=(ALL) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/010_$user-nopasswd 
}
declare -fx nopasswd_sudo

set_hostname(){
    local newname="${1:?Missing argument: <newname>}"
    local oldname="$(hostname)"
    [[ -n "$newname" ]] || die "No hostname specified" || return -1
    echo "Changing hostname from '$oldname' to '$newname'"
    sudo hostname "$1" && { 
        sudo sed -i "s/$oldname/$newname/g" /etc/hosts
        hostname | sudo tee /etc/hostname >/dev/null
        [[ -f /var/lib/cloud/seed/nocloud-net/user-data ]] && 
            sudo sed -ri "s/(hostname: ).*\$/\1$newname/" \
                /var/lib/cloud/seed/nocloud-net/user-data
        exec $SHELL
    }
}
declare -fx set_hostname

set_prompt_colors(){
    sed -ri 's/^#?(force_color_prompt=).*/\1yes/g' $target{/etc/skel,/root,/home/*}/.bashrc &> /dev/null
    [[ ! -f  $target/root/.bashrc ]] && cp $target{/etc/skel/.bashrc,/root/}
    sed -i "s/PS1='/PS1='\\\[\\\033[01;33m\\\]/g; s/01;32m/01;31m/g" $target/root/.bashrc
}

set_timezone(){
    local tz="${1:-Europe/Brussels}"
    sudo timedatectl set-timezone "$tz"
}
declare -fx set_timezone

add_default_groups(){
    local user="$1"
    sudo usermod -aG adm,dialout,cdrom,audio,users,sudo,video,games,plugdev,input,gpio,spi,i2c,netdev "$user"
}
declare -fx add_default_groups

add_user(){
    local user="${1:?Missing argument: <username>}"
    [[ -n "$user" ]] || { die "Usage: $0 USERNAME" || return 1; } 
    id "$user" &>/dev/null && { die "User '$user' exists!" || return 1; }
    sudo adduser "$user" --gecos "" --disabled-password 
    add_default_groups "$user"
    nopasswd_sudo "$user"
    sudo passwd "$user"
}
declare -fx add_user

mkvenv(){
    local opts="" dir="$PWD"
    while [[ -n "$1" ]]; do
        case "$1" in
            -s) opts+="--system-site-packages" ;;
            -d) dir="$2"; shift ;;
            *) local name="$1" ;;
        esac
        shift
    done
    msg "Creating new environment '${name:=venv}' in ${dir}..."
    pushd "$dir" >/dev/null
    python3 -m venv "$env" 
    "$env/bin/python3" -m pip install --upgrade pip setuptools wheel 
    source "$env/bin/activate"
    popd >/dev/null
}
declare -fx mkvenv

update() {
    tmp="$(mktemp)"
    if wget -qO "${tmp}" https://raw.githubusercontent.com/nmctseb/RPi-tools/master/nmctool; then
        sudo install -v -m 755 "${tmp}" /usr/local/bin/nmctool
    else
	err "Update failed"
	return 1
    fi

}

usage(){
    cat <<-EOF 
    usage: $0 <command> [<args>]

    Available commands:
      add-user <name>
        - add new user account
      fix-groups [<user>]    
        - fix group memberships (gpio, i2c, ...) for current or <specified user> 
      hostname <newname>
        - change system hostname to <newname>
      keyboard <layout>
        - change console keyboard layout. 
          <layout> is a 2 letter code, e.g. us, gb, be, nl, ... 
      lazy-sudo[<user>]
        - add rule to enable sudo without password   
      timezone <tz>
        - set timezone to <tz>, e.g. Europe/Brussels
      new-venv [-s] <name>
        - make a new Python3 virtual environment in <name> 
          -s: inherit system-site-packages
      update
	- update this tool to the latest version

EOF
}

is_sourced || {
    op="$1"; shift
    case "$op" in 
        add-user)      add_user "$@"                ;;
        fix-groups)    add_default_groups "$@"      ;;
        hostname)      set_hostname "$@"            ;;
        keyboard)      set_keyboard "$@"            ;;
        lazy-sudo)     nopasswd_sudo "$@"           ;;
        timezone)      set_timezone "$@"            ;;
        new-venv)      mkvenv "$@"                  ;;
	update)	       update "$@"		    ;;
	help)	       usage "$@"		    ;;
        *) usage 1>&2  				    ;;
    esac
}