fix(bootstrap): keep a nano host's listen address and mode on re-run

# generated secrets are persisted to /etc/felis/secrets.env so reruns reuse them.

#

# Tunables (export before running to override the demo defaults):

#   FELIS_INSTALL_MODE full|nano — skip the prompt (default: ask on a tty, else full)

#   FELIS_NANO_LISTEN listen addr for `felis nano` (default: 127.0.0.1:8081 — loopback

#                     only; set a private-network IP to serve an off-host proxy)

#   FELIS_INSTALL_MODE full|nano — skip the prompt (default: ask on a tty, else full; nano

#                     instead on a host that runs felis-nano and no full install)

#   FELIS_NANO_LISTEN listen addr for `felis nano` (default: the address an installed

#                     felis-nano already uses, else 127.0.0.1:8081 — loopback only; set a

#                     private-network IP to serve an off-host proxy)

#   FELIS_LEGACY_FORWARDING_SERVERS comma-separated backends that receive their identity

#                     through the handshake address instead of modern forwarding

#                     (default: legacy18). Read once at Velocity start, so changing it

# proxy at it and spend YOUR egress IP on Mojang, until Mojang rate-limits you and your

# own players stop getting in. Same-host Velocity reaches 127.0.0.1 fine; a proxy on

# another machine must opt in explicitly with FELIS_NANO_LISTEN=<private-ip>:8081.

FELIS_NANO_LISTEN="${FELIS_NANO_LISTEN:-127.0.0.1:8081}"

# Left empty here: resolve_nano_listen applies that default only after an existing unit's

# address has had its say.

FELIS_NANO_LISTEN="${FELIS_NANO_LISTEN:-}"

# Backends that take their forwarded identity through the handshake address instead of

# proxy-wide modern forwarding. See write_velocity_service for why a protocol-47 backend

# needs this. Overridable because adding a second 1.8 backend otherwise means editing this

    *) die "FELIS_INSTALL_MODE must be 'full' or 'nano', got: ${INSTALL_MODE}" ;;

  esac

  # A felis-nano unit with no full install beside it makes this re-run a nano update;

  # defaulting to full there would put k3s and Postgres on a host that asked for neither.

  local def=full n=1 reply

  if [ -e "$NANO_SERVICE" ] && [ ! -e "$BOOTSTRAP_DONE" ]; then def=nano n=2; fi

  # No override: ask on the controlling terminal. Under `curl | sudo bash` stdin

  # is the script, so we must read /dev/tty, not stdin. No tty (CI/cloud-init) →

  # default to a full install.

  # take the default.

  if [ ! -r /dev/tty ]; then

    INSTALL_MODE="full"

    log "no terminal for a prompt; defaulting to a full Felis install (set FELIS_INSTALL_MODE=nano to override)"

    INSTALL_MODE="$def"

    log "no terminal for a prompt; defaulting to a ${def} install (set FELIS_INSTALL_MODE=full or nano to override)"

    return 0

  fi

  printf 'What do you want to install on this host?\n'

  printf '  [1] Felis       — full control plane (k3s + Postgres + panel; orchestrates Minecraft servers)\n'

  printf '  [2] Felis-nano  — auth multiplexer only (federates Mojang + third-party Yggdrasil; no k3s/DB)\n'

  local reply

  while :; do

    printf 'Choose [1/2] (default 1): '

    printf 'Choose [1/2] (default %s): ' "$n"

    IFS= read -r reply </dev/tty || reply=""

    case "$reply" in

      ""|1|full|Felis|felis) INSTALL_MODE="full"; break ;;

      "") INSTALL_MODE="$def"; break ;;

      1|full|Felis|felis) INSTALL_MODE="full"; break ;;

      2|nano|felis-nano|Felis-nano) INSTALL_MODE="nano"; break ;;

      *) printf 'Please enter 1 or 2.\n' ;;

    esac

  ok "wrote nano config template ${target} (edit it to add your Yggdrasil sources)"

}

# resolve_nano_listen settles FELIS_NANO_LISTEN: the operator's value, else the address the

# installed felis-nano unit listens on, else loopback. Re-running this script is how a nano

# host updates, and without the middle step that re-run moved an off-host proxy's endpoint

# back to 127.0.0.1, so every login through it failed.

resolve_nano_listen() {

  if [ -z "$FELIS_NANO_LISTEN" ] && [ -r "$NANO_SERVICE" ]; then

    FELIS_NANO_LISTEN="$(sed -n 's/^ExecStart=.* -listen \([^ ]*\).*$/\1/p' "$NANO_SERVICE")"

  fi

  FELIS_NANO_LISTEN="${FELIS_NANO_LISTEN:-127.0.0.1:8081}"

}

nano_listen_is_loopback() {

  case "${FELIS_NANO_LISTEN%:*}" in

    127.*|localhost|::1|"[::1]") return 0 ;;

}

main() {

  resolve_nano_listen

  validate_settings

  detect_os

  prompt_install_mode

out="$(run_nano_service 0)"

expect "a unit that stays up is reported as started" "OK: felis-nano.service enabled and started" "$out"

# --- a re-run on a nano host keeps what that host is --------------------------------------

# Re-running the installer is how a nano host updates. It must not move the endpoint an

# off-host proxy points at, nor default a nano-only host to the full control plane. The unit

# read back here is the one install_nano_service wrote above.

rblock="$(awk '/^resolve_nano_listen\(\) \{/,/^}/' "$BS")"

[ -n "$rblock" ] || { echo "FAIL: no resolve_nano_listen found in $BS"; exit 1; }

[ "$(printf '%s\n' "$rblock" | wc -l)" -lt 20 ] \

  || { echo "FAIL: the extracted block is not the function -- did its closing brace move?"; exit 1; }

run_listen() { # env-value unit-path

  FELIS_NANO_LISTEN="$1" NANO_SERVICE="$2" bash -c "$rblock"'

    resolve_nano_listen

    printf "LISTEN: %s\n" "$FELIS_NANO_LISTEN"'

}

expect "a re-run keeps the unit's listen address" "LISTEN: 127.0.0.1:25580" \

  "$(run_listen '' "$sdir/felis-nano.service")"

expect "the operator's address beats the unit's" "LISTEN: 10.0.0.5:8081" \

  "$(run_listen 10.0.0.5:8081 "$sdir/felis-nano.service")"

expect "a first install listens on loopback" "LISTEN: 127.0.0.1:8081" \

  "$(run_listen '' "$sdir/absent.service")"

expect "a first install takes the operator's address" "LISTEN: 10.0.0.5:8081" \

  "$(run_listen 10.0.0.5:8081 "$sdir/absent.service")"

pblock="$(awk '/^prompt_install_mode\(\) \{/,/^}/' "$BS")"

[ -n "$pblock" ] || { echo "FAIL: no prompt_install_mode found in $BS"; exit 1; }

[ "$(printf '%s\n' "$pblock" | wc -l)" -lt 60 ] \

  || { echo "FAIL: the extracted block is not the function -- did its closing brace move?"; exit 1; }

# Only the no-terminal path can run unattended, and with a terminal attached the prompt

# would sit waiting on it. setsid drops the controlling terminal, as cloud-init and CI have.

notty=""

if (: </dev/tty) 2>/dev/null; then

  if command -v setsid >/dev/null 2>&1; then notty=setsid; else notty=skip; fi

fi

run_mode() { # unit-path done-marker-path [FELIS_INSTALL_MODE]

  INSTALL_MODE="${3:-}" NANO_SERVICE="$1" BOOTSTRAP_DONE="$2" $notty bash -c '

    die() { printf "DIE: %s\n" "$*"; exit 1; }

    log() { printf "LOG: %s\n" "$*"; }

    '"$pblock"'

    prompt_install_mode </dev/null

    printf "MODE: %s\n" "$INSTALL_MODE"' 2>&1

}

if [ "$notty" = skip ]; then

  echo "SKIP install-mode default: a terminal is attached and there is no setsid to drop it"

else

  : > "$sdir/bootstrap.done"

  expect "a nano-only host re-runs as nano" "MODE: nano" \

    "$(run_mode "$sdir/felis-nano.service" "$sdir/absent.done")"

  expect "a host with the full install re-runs as full" "MODE: full" \

    "$(run_mode "$sdir/felis-nano.service" "$sdir/bootstrap.done")"

  expect "a fresh host defaults to full" "MODE: full" \

    "$(run_mode "$sdir/absent.service" "$sdir/absent.done")"

fi

# ---------------------------------------------------------------------------------------

if [ "$fails" -eq 0 ]; then

  echo "ALL PASS"