Dockerfile

FROM postgres:9.4

ENV PGDATA /pgdata

COPY test.sql /docker-entrypoint-initdb.d/
COPY restore.sh /restore.sh

RUN /restore.sh

old.Dockerfile

FROM postgres:9.4

ENV PGDATA /pgdata

COPY test.sql /docker-entrypoint-initdb.d/
RUN /docker-entrypoint.sh postgres

restore.sh

#!/bin/bash

PIPEFILE="pipefile"
ENTRY_PID=""

[[ -p "$PIPEFILE" ]] || mkfifo "$PIPEFILE"
/docker-entrypoint.sh postgres > "$PIPEFILE" & ENTRY_PID="$!"

while read LINE ; do
    echo $LINE

    if [[ "$LINE" == *"ready for start up"* ]] ; then
        sleep 3
        break
    fi
done < "$PIPEFILE"

kill -s TERM "$ENTRY_PID" && wait "$ENTRY_PID"

test.sql

CREATE DATABASE gongo;

\c gongo;

CREATE TABLE users (
  name   text,
  age    integer
);

INSERT INTO users (name, age) VALUES ('gongo', 999), ('du', 666);