bootstrap

#!/usr/bin/env bash
# Copyright (c) 2021 The Toltec Contributors
# SPDX-License-Identifier: MIT

#
# bootstrap
#
# Install and configure Opkg, Entware and Toltec
#
# Arguments: Additional packages to install after setting up Toltec
# Example: ./bootstrap harmony draft
#
# Based on Evan Widloski’s remarkable_entware (2019-03-21)
# Based on the Entware installer from
# <http://bin.entware.net/armv7sf-k3.2/installer/generic.sh>
#

set -eE

# Path for the temporary local wget used in this installer
[[ -z $wget_path ]] && wget_path=/home/root/.local/bin/wget

# Path for the systemd unit that mounts Entware to /opt
[[ -z $old_systemd_mount_path ]] && old_systemd_mount_path=/etc/systemd/system/opt.mount
[[ -z $systemd_mount_path ]] && systemd_mount_path=/lib/systemd/system/opt.mount

# Path where the actual Entware distribution resides (will be mounted to /opt)
[[ -z $entware_path ]] && entware_path=/home/root/.entware

# Find out current branch or get default one
get-branch() {
    local opkg_conf="$entware_path/etc/opkg.conf"
    local branch
    if [[ -f "$opkg_conf" ]]; then
        # Get the first (...) value (aka \1) of the pattern if matching
        branch="$(sed -E 's|^src/gz\s+toltec\s+https://toltec-dev.org/([[:alnum:]]*).*$|\1|;t;d' "$opkg_conf" | head -n1)"
    fi
    echo "${branch:-stable}"
}

# Toltec branch to use for this install - you almost always want the default
[[ -z $toltec_branch ]] && toltec_branch="$(get-branch)"

# Remove all temporary files
cleanup() {
    if [[ -e $wget_path ]]; then
        rm "$wget_path"
    fi
}

# Remove unfinished installation after unexpected error
error-cleanup() {
    read -ra trace < <(caller 0)
    log ERROR "Unexpected error on line ${trace[2]}:${trace[0]} in function ${trace[1]}"

    # Get out of /opt so it can be unmounted
    cd /home/root

    if [[ -d /opt ]]; then
        umount /opt
        rm /opt -rf
    fi

    if [[ -d $entware_path ]]; then
        rm -rf "$entware_path"
    fi

    if [[ -f $systemd_mount_path ]]; then
        systemctl disable --now opt.mount 2> /dev/null
        rm "$systemd_mount_path"
        systemctl daemon-reload
    fi

    log ERROR "This script failed to install. If you can't solve the above" \
        "issue yourself, please report it at:" \
        "" \
        "   https://github.com/toltec-dev/toltec/issues" \
        "" \
        "(Please also include these error logs to help solving the" \
        "problem faster. Thank you!)"
}

# Install a local wget binary which supports TLS (the original one
# installed on the reMarkable does not) in the PATH
wget-bootstrap() {
    local wget_remote=https://toltec-dev.org/thirdparty/bin/wget-v1.21.1
    local wget_checksum=8798fcdabbe560722a02f95b30385926e4452e2c98c15c2c217583eaa0db30fc

    if [[ ! -x $wget_path ]]; then
        if [[ -e $wget_path ]]; then
            log ERROR "'$wget_path' exists, but is not executable"
            error-cleanup
            exit 1
        fi

        # Download and compare to hash
        mkdir -p "$(dirname "$wget_path")"
        wget "$wget_remote" --output-document "$wget_path" 2> /dev/null

        if ! sha256sum -c <(echo "$wget_checksum  $wget_path") > /dev/null 2>&1; then
            log ERROR "Invalid checksum for the local wget binary"
            error-cleanup
            exit 1
        fi

        chmod +x "$wget_path"
    fi

    # Ensure the local binary is used
    if [[ $(command -v wget) != "$wget_path" ]]; then
        export PATH
        PATH="$(dirname "$wget_path"):$PATH"
    fi
}

# Mount Entware to /opt
entware-mount() {
    mkdir -p /opt
    mkdir -p "$entware_path"

    if [[ -f $old_systemd_mount_path ]] && [[ ! -f $systemd_mount_path ]]; then
        # The user was probably using https://github.com/Evidlo/remarkable_entware
        # before switching to toltec. Removing old .mount file to prevent duplicate files
        log "Updating opt.mount location"

        if systemctl -q is-enabled opt.mount; then
            # Remove path to old file if still symlinked
            systemctl disable opt.mount
        fi
        rm $old_systemd_mount_path
    fi

    # Create systemd mount unit to mount over /opt on reboot
    cat > "$systemd_mount_path" << UNIT
[Unit]
Description=Bind mount Entware over /opt
DefaultDependencies=no
Conflicts=umount.target
Before=local-fs.target umount.target

[Mount]
What=/home/root/.entware
Where=/opt
Type=none
Options=bind

[Install]
WantedBy=local-fs.target
UNIT

    systemctl daemon-reload
    systemctl enable --now opt.mount 2> /dev/null
}

# Install Entware to /opt
entware-install() {
    log "Installing Entware to /opt"

    # Create basic folders, entware-opt package creates the rest
    for folder in bin etc lib lib/opkg tmp var var/lock; do
        if [ -d "/opt/$folder" ]; then
            log WARN "Folder /opt/$folder exists!" \
                "If something goes wrong please clean the /opt folder and try again."
        else
            mkdir "/opt/$folder"
        fi
    done

    local dynamic_loader="ld-linux.so.3"
    local entware_remote=https://bin.entware.net/armv7sf-k3.2/installer

    wget --no-verbose "$entware_remote/opkg" -O /opt/bin/opkg
    chmod 755 /opt/bin/opkg
    wget --no-verbose "$entware_remote/opkg.conf" -O /opt/etc/opkg.conf
    sed -i 's|http://|https://|g' /opt/etc/opkg.conf
    wget --no-verbose "$entware_remote/ld-2.27.so" -O /opt/lib/ld-2.27.so
    wget --no-verbose "$entware_remote/libc-2.27.so" -O /opt/lib/libc-2.27.so
    wget --no-verbose "$entware_remote/libgcc_s.so.1" -O /opt/lib/libgcc_s.so.1
    wget --no-verbose "$entware_remote/libpthread-2.27.so" -O /opt/lib/libpthread-2.27.so

    cd /opt/lib
    chmod 755 ld-2.27.so
    ln -s ld-2.27.so "$dynamic_loader"
    ln -s libc-2.27.so libc.so.6
    ln -s libpthread-2.27.so libpthread.so.0

    /opt/bin/opkg update
    /opt/bin/opkg install entware-opt

    # Fix for multiuser environment
    chmod 777 /opt/tmp

    # Create basic administrative files
    if [[ -f /etc/passwd ]]; then
        ln -sf /etc/passwd /opt/etc/passwd
    else
        cp /opt/etc/passwd.1 /opt/etc/passwd
    fi

    if [[ -f /etc/group ]]; then
        ln -sf /etc/group /opt/etc/group
    else
        cp /opt/etc/group.1 /opt/etc/group
    fi

    if [[ -f /etc/shells ]]; then
        ln -sf /etc/shells /opt/etc/shells
    else
        cp /opt/etc/shells.1 /opt/etc/shells
    fi

    if [[ -f /etc/shadow ]]; then
        ln -sf /etc/shadow /opt/etc/shadow
    fi

    if [[ -f /etc/gshadow ]]; then
        ln -sf /etc/gshadow /opt/etc/gshadow
    fi

    if [[ -f /etc/localtime ]]; then
        ln -sf /etc/localtime /opt/etc/localtime
    fi
}

# Add Toltec configuration to an existing Entware install
#
# Arguments: List of additional packages to install, one package per argument
toltec-install() {
    # Make sure that Opkg is configured to fetch the chosen Toltec branch
    if grep -q "^src/gz\b.*\bhttps://toltec-dev\.org/$toltec_branch$" /opt/etc/opkg.conf; then
        log "Already on the Toltec $toltec_branch branch"
    else
        log "Adding the Toltec $toltec_branch repository"
        sed -i '/^src\/gz\b.*\bhttps:\/\/toltec\.delab\.re\//d' /opt/etc/opkg.conf
        sed -i '/^src\/gz\b.*\bhttps:\/\/toltec-dev\.org\//d' /opt/etc/opkg.conf
        echo "src/gz toltec https://toltec-dev.org/$toltec_branch" >> /opt/etc/opkg.conf
    fi
    /opt/bin/opkg update

    # Make sure that the packages needed for wget TLS support are installed
    local additional_packages=()

    [[ ! -d /opt/etc/ssl/certs ]] && additional_packages+=(ca-certificates)
    [[ ! -f /opt/bin/wget ]] && additional_packages+=(wget)

    if [[ ${#additional_packages[@]} -gt 0 ]]; then
        /opt/bin/opkg install "${additional_packages[@]}"
    fi

    /opt/bin/opkg update
    /opt/bin/opkg install toltec-bootstrap

    # Install additional packages
    if [[ $# -gt 0 ]]; then
        /opt/bin/opkg install "$@"
    fi

    # Remove existing PATH definitions where the binaries in /opt/bin and
    # /opt/sbin have lesser priority than the others
    # shellcheck disable=SC2016
    if [[ -e /home/root/.bashrc ]]; then
        sed -i '/^\(export \)\?PATH="\?\$PATH:\/opt\/bin:\/opt\/sbin"\?$/d' /home/root/.bashrc
    fi

    # Add binaries in /opt/bin and /opt/sbin to the PATH before any others
    # shellcheck disable=SC2016
    if [[ ! -e /home/root/.bashrc ]] \
        || ! grep -q '^\(export \)\?PATH="\?/opt/bin:/opt/sbin:\$PATH"\?$' /home/root/.bashrc; then
        log "Adding /opt/bin and /opt/sbin to your PATH"
        log "Please run '. \$HOME/.bashrc' to use Toltec"
        cat >> /home/root/.bashrc << 'SHELL'
# Path added by Toltec bootstrap
PATH="/opt/bin:/opt/sbin:$PATH"
SHELL
    fi
}

# Print a log message
#
# Arguments:
#
# [$1] - Log level: INFO, WARN or ERROR (default: INFO)
# $2... - Messages to print, each argument goes to a separate line
log() {
    # Output stream where the messages will be sent
    local log_type="INFO"
    local fd=1
    local colored_prefix

    if [[ $# -ge 2 ]]; then
        case "$1" in
            INFO | WARN | ERROR)
                log_type="$1"
                shift
                ;;
        esac
    fi

    case "$log_type" in
        INFO) colored_prefix='\e[32mINFO:\e[0m  ' ;;
        WARN)
            colored_prefix='\e[33mWARN:\e[0m  '
            fd=2
            ;;
        ERROR)
            colored_prefix='\e[31mERROR:\e[0m '
            fd=2
            ;;
    esac

    echo -e "${colored_prefix}$1" >&$fd

    # Extra lines to print indented
    shift
    local line

    for line in "$@"; do
        echo -e "       $line" >&$fd
    done
}

main() {
    trap cleanup EXIT
    trap error-cleanup ERR

    if [[ "$(command -v wget)" == /usr/bin/wget ]]; then
        log "Fetching secure wget"
        wget-bootstrap
    fi

    if [[ -d $entware_path ]]; then
        if [[ -d /opt ]] && files="$(ls -A -- /opt)" && [[ -n $files ]]; then
            log "Entware is already installed and active"
        else
            log "Re-enabling existing Entware install"
            entware-mount
        fi
    else
        log "Creating $entware_path and mounting to /opt"
        entware-mount
        entware-install
    fi

    toltec-install "$@"
    log "Use '/home/root/entware-reenable' to re-enable Toltec after a system update"
}

main "$@"