use the entrypoint.sh script from the base image

bitnami/postgresql/Dockerfile

@@ -3,6 +3,7 @@ MAINTAINER Bitnami <containers@bitnami.com>
 
 ENV BITNAMI_APP_DIR=$BITNAMI_PREFIX/postgresql \
     BITNAMI_APP_NAME=postgresql \
+    BITNAMI_APP_DAEMON=postgres \
     BITNAMI_APP_USER=postgres \
     BITNAMI_APP_VERSION=9.4.4-1
 

bitnami/postgresql/rootfs/entrypoint.sh

@@ -1,16 +0,0 @@
-#!/bin/bash
-
-if [ "${1:0:1}" = '-' ]; then
-  export EXTRA_OPTIONS="$@"
-  set --
-elif [ "${1}" == "postgres" -o "${1}" == "$(which postgres)" ]; then
-  export EXTRA_OPTIONS="${@:2}"
-  set --
-fi
-
-if [ -n "${1}" ]; then
-  touch /etc/services.d/$BITNAMI_APP_NAME/down
-  touch /etc/services.d/$BITNAMI_APP_NAME-logs/down
-fi
-
-exec /init "$@"

bitnami/postgresql/rootfs/etc/services.d/postgresql/run

@@ -5,4 +5,4 @@ export LD_LIBRARY_PATH=$BITNAMI_PREFIX/common/lib
 
 mkdir -p $BITNAMI_APP_DIR/tmp
 date '+%d%H%M%S' > $BITNAMI_APP_DIR/tmp/start
-exec s6-setuidgid $BITNAMI_APP_USER postgres $PROGRAM_OPTIONS ${EXTRA_OPTIONS:+"$EXTRA_OPTIONS"}
+exec s6-setuidgid $BITNAMI_APP_USER $BITNAMI_APP_DAEMON $PROGRAM_OPTIONS ${EXTRA_OPTIONS:+"$EXTRA_OPTIONS"}