#!/bin/sh
set -eu

# Re-exec outside of apparmor confinement
if [ -d /sys/kernel/security/apparmor ]; then
  label="$(cat /proc/self/attr/current 2>/dev/null)"
  if [ "$label" != "unconfined" ] && [ -n "${label##*(unconfined)}" ]; then
    if ! aa-exec --help >/dev/null 2>&1; then
        echo "The LXD snap was unable to run aa-exec, this usually indicates a LXD sideload." >&2
        echo "When sideloading, make sure to manually connect all interfaces." >&2
        exit 0
    fi

    exec aa-exec -p unconfined -- "$0" "$@" || true
  fi
fi

# shellcheck disable=SC2155
export SNAP_CURRENT="$(realpath "${SNAP}/..")/current"

# Turn `/snap/lxd/28637/lib/x86_64-linux-gnu` into `x86_64-linux-gnu`
# Similar to `basename` but using variable substitution instead of external executable
LIB_ARCH="$(readlink -f "${SNAP_CURRENT}"/lib/*-linux-gnu*/)"
export ARCH="${LIB_ARCH##*/}"

export LD_LIBRARY_PATH="${LD_LIBRARY_PATH:-}:${SNAP_CURRENT}/lib:${SNAP_CURRENT}/lib/${ARCH}:${SNAP_CURRENT}/lib/${ARCH}/ceph"
export PATH="${PATH}:${SNAP_CURRENT}/bin"
export LXD_DIR="${LXD_DIR:-"${SNAP_COMMON}/lxd/"}"

echo "=> Starting LXD activation"

# Load our configuration
if [ ! -e "${SNAP_COMMON}/config" ]; then
    echo "==> Creating missing snap configuration"
    "${SNAP_CURRENT}/meta/hooks/configure"
fi

echo "==> Loading snap configuration"
# shellcheck disable=SC1091
. "${SNAP_COMMON}/config"

daemon_group="${daemon_group:-"lxd"}"
daemon_user_group="${daemon_user_group:-"lxd"}"

# Detect missing socket activation support
echo "==> Checking for socket activation support"
if ! nsenter -t 1 -m systemctl is-active -q snap."${SNAP_INSTANCE_NAME}".daemon.unix.socket; then
    sleep 3s
    if ! nsenter -t 1 -m systemctl is-active -q snap."${SNAP_INSTANCE_NAME}".daemon.unix.socket; then
        echo "===> System doesn't support socket activation, starting LXD now"
        nsenter -t 1 -m systemctl start snap."${SNAP_INSTANCE_NAME}".daemon
        exit 0
    fi
fi

# Start LXD if running as an appliance
if nsenter -t 1 -m snap model --assertion | grep -q "^model: lxd-core"; then
    echo "==> LXD appliance detected, starting LXD"
    nsenter -t 1 -m systemctl start snap."${SNAP_INSTANCE_NAME}".daemon --no-block
    exit 0
fi

# Setup the "lxd" group
if [ "${daemon_group}" = "lxd" ] && ! getent group lxd >/dev/null 2>&1; then
    echo "==> Creating \"lxd\" group"
    if grep -q "^group.*extrausers" /var/lib/snapd/hostfs/etc/nsswitch.conf; then
        nsenter -t 1 -m groupadd --system --extrausers lxd || true
    else
        nsenter -t 1 -m groupadd --system lxd || true
    fi
fi

# Setup the "lxd" user
if ! getent passwd lxd >/dev/null 2>&1; then
    echo "==> Creating \"lxd\" user"
    if grep -q "^passwd.*extrausers" /var/lib/snapd/hostfs/etc/nsswitch.conf; then
        nsenter -t 1 -m useradd --system -M -N --home "${SNAP_COMMON}/lxd" --shell /bin/false --gid lxd --extrausers lxd || true
    else
        nsenter -t 1 -m useradd --system -M -N --home "${SNAP_COMMON}/lxd" --shell /bin/false --gid lxd lxd || true
    fi
fi

# Set socket ownership
if getent group "${daemon_group}" >/dev/null 2>&1; then
    if [ -e "${SNAP_COMMON}/lxd/unix.socket" ]; then
        echo "==> Setting LXD socket ownership"
        chgrp "${daemon_group}" "${SNAP_COMMON}/lxd/unix.socket"
    fi
fi

if getent group "${daemon_user_group}" >/dev/null 2>&1; then
    if [ -e "${SNAP_COMMON}/lxd-user/unix.socket" ]; then
        echo "==> Setting LXD user socket ownership"
        chgrp "${daemon_user_group}" "${SNAP_COMMON}/lxd-user/unix.socket"
    fi
fi

# Check if LXD ever started
if [ ! -d "${SNAP_COMMON}/lxd/database" ]; then
    echo "==> LXD never started on this system, no need to start it now"
    exit 0
fi

# Check if LXD should start
LXD="lxd"
if [ -x "${SNAP_COMMON}/lxd.debug" ]; then
    LXD="${SNAP_COMMON}/lxd.debug"
    echo "==> WARNING: Using a custom debug LXD binary!"
fi

echo "==> Checking if LXD needs to be activated"
if ! "${LXD}" activateifneeded; then
    echo "====> Activation check failed, forcing activation"
    nsenter -t 1 -m systemctl start snap."${SNAP_INSTANCE_NAME}".daemon
fi

exit 0