Add robust shebang detection to .templates/01-config_yaml.sh

Co-authored-by: alexbelgium <44178713+alexbelgium@users.noreply.github.com>

.templates/01-config_yaml.sh

@@ -1,6 +1,146 @@
-#!/usr/bin/with-contenv bashio
+#!/bin/bash
 # shellcheck shell=bash
 
+##########################################
+# Pick an exec-capable directory         #
+##########################################
+
+pick_exec_dir() {
+  local d
+  for d in /dev/shm /run /var/run /mnt /root /; do
+    if [ -d "$d" ] && [ -w "$d" ]; then
+      local t="${d%/}/.exec_test_$$"
+      printf '#!/bin/sh\necho ok\n' >"$t" 2>/dev/null || { rm -f "$t" 2>/dev/null || true; continue; }
+      chmod 700 "$t" 2>/dev/null || { rm -f "$t" 2>/dev/null || true; continue; }
+      if "$t" >/dev/null 2>&1; then
+        rm -f "$t" 2>/dev/null || true
+        echo "$d"
+        return 0
+      fi
+      rm -f "$t" 2>/dev/null || true
+    fi
+  done
+  return 1
+}
+
+EXEC_DIR="$(pick_exec_dir || true)"
+if [ -z "${EXEC_DIR:-}" ]; then
+  echo "ERROR: Could not find an exec-capable writable directory."
+  exit 1
+fi
+
+######################
+# Select the shebang #
+######################
+
+candidate_shebangs=(
+  "/command/with-contenv bashio"
+  "/usr/bin/with-contenv bashio"
+  "/usr/bin/env bashio"
+  "/usr/bin/bashio"
+  "/usr/bin/bash"
+  "/bin/bash"
+  "/usr/bin/sh"
+  "/bin/sh"
+)
+
+SHEBANG_ERRORS=()
+
+probe_script_content='
+set -e
+
+if ! command -v bashio::addon.version >/dev/null 2>&1; then
+  for f in \
+    /usr/lib/bashio/bashio.sh \
+    /usr/lib/bashio/lib.sh \
+    /usr/src/bashio/bashio.sh \
+    /usr/local/lib/bashio/bashio.sh
+  do
+    if [ -f "$f" ]; then
+      . "$f"
+      break
+    fi
+  done
+fi
+
+bashio::addon.version
+'
+
+validate_shebang() {
+  local candidate="$1"
+  local tmp out rc
+  local errfile msg
+
+  # shellcheck disable=SC2206
+  local cmd=( $candidate )
+  local exe="${cmd[0]}"
+
+  if [ ! -x "$exe" ]; then
+    SHEBANG_ERRORS+=(" - FAIL (not executable): #!$candidate")
+    return 1
+  fi
+
+  tmp="${EXEC_DIR%/}/shebang_test.$$.$RANDOM"
+  errfile="${EXEC_DIR%/}/shebang_probe_err.$$"
+  {
+    printf '#!%s\n' "$candidate"
+    printf '%s\n' "$probe_script_content"
+  } >"$tmp"
+  chmod 700 "$tmp" 2>/dev/null || true
+
+  set +e
+  out="$("$tmp" 2>"$errfile")"
+  rc=$?
+  set -e
+
+  rm -f "$tmp" 2>/dev/null || true
+
+  if [ "$rc" -eq 0 ] && [ -n "${out:-}" ] && [ "$out" != "null" ]; then
+    rm -f "$errfile" 2>/dev/null || true
+    return 0
+  fi
+
+  msg=$' - FAIL: #!'"$candidate"$'\n'"   rc=$rc, stdout='${out:-}'"$'\n'
+  if [ -s "$errfile" ]; then
+    msg+=$'   stderr:\n'
+    msg+="$(sed -n '1,8p' "$errfile")"$'\n'
+  else
+    msg+=$'   stderr: <empty>\n'
+  fi
+  SHEBANG_ERRORS+=("$msg")
+  rm -f "$errfile" 2>/dev/null || true
+  return 1
+}
+
+shebang=""
+for candidate in "${candidate_shebangs[@]}"; do
+  if validate_shebang "$candidate"; then
+    shebang="$candidate"
+    break
+  fi
+done
+
+if [ -z "$shebang" ]; then
+  echo "ERROR: No valid shebang found." >&2
+  printf ' - %s\n' "${candidate_shebangs[@]}" >&2
+  if [ "${#SHEBANG_ERRORS[@]}" -gt 0 ]; then
+    printf '%s\n' "${SHEBANG_ERRORS[@]}" >&2
+  fi
+  exit 1
+fi
+
+sed -i "1s|^.*|#!$shebang|" "$0"
+
+if ! command -v bashio::addon.version >/dev/null 2>&1; then
+  for f in /usr/lib/bashio/bashio.sh /usr/lib/bashio/lib.sh /usr/src/bashio/bashio.sh /usr/local/lib/bashio/bashio.sh; do
+    if [ -f "$f" ]; then
+      # shellcheck disable=SC1090
+      . "$f"
+      break
+    fi
+  done
+fi
+
 ##################
 # INITIALIZATION #
 ##################