php-fpm: refactor with deterministic config files & improved debug

shared/php-fpm/entrypoint.sh

@@ -1,12 +1,19 @@
 #!/bin/sh
-set -euo pipefail
+set -eu
 
-: ${CHOWN_ON_START:=}
-if [ "${CHOWN_ON_START}" = "1" ] || [ "${CHOWN_ON_START}" = "true" ]; then
-  echo "[entrypoint] CHOWN_ON_START enabled — fixing ownership of /var/www/html"
-  if [ -d /var/www/html ]; then
-    chown -R 1000:1000 /var/www/html || true
-  fi
+PHP_ENTRYPOINT="/usr/local/bin/docker-php-entrypoint"
+if [ ! -x "${PHP_ENTRYPOINT}" ]; then
+  echo "[entrypoint] Missing ${PHP_ENTRYPOINT}" >&2
+  exit 1
 fi
 
-exec "$@"
+case "${CHOWN_ON_START:-}" in
+  1|true|TRUE|yes|on)
+    echo "[entrypoint] CHOWN_ON_START enabled — fixing ownership of /var/www/html"
+    if [ -d /var/www/html ]; then
+      chown -R 1000:1000 /var/www/html || true
+    fi
+    ;;
+esac
+
+exec "${PHP_ENTRYPOINT}" "$@"