在 docker 容器中创建正在运行的 Postgres 服务

Question

I'm a bit new to Docker.
I have two containers running using docker-compose.
One is the API and the other is the actual application.
I want to add a new DB container using the Postgres official image.
It's a bit hard to find a simple tutorial on how to create the container and populate it with a predefined sql file (of schemas and data).

When I start with "CMD /etc/init.d/postgresql start" in the Dockerfile I get an error saying: "No PostgreSQL clusters exist; see "man pg_createcluster"... (warning)."

Since it takes me too much time to get things going I was wondering if it might be better to get an Ubuntu image and install Postgres on my own since there is only one source on how to use the image - docker hub, and I don't seem to understand it that well.

Any ideas or simple steps on how to compose and 'configure' this image?

Answer 1

If you want populate your database with some file, A simply way to do this is:

How to extend this image

If you would like to do additional initialization in an image derived from this one, add one or more *.sql, *.sql.gz, or *.sh scripts under /docker-entrypoint-initdb.d (creating the directory if necessary). After the entrypoint calls initdb to create the default postgres user and database, it will run any *.sql files and source any *.sh scripts found in that directory to do further initialization before starting the service.

Dockerfile

FROM postgres:alpine
COPY init.sql /docker-entrypoint-initdb.d/init.sql

docker-compose.yml

version: '3'
services:
  app:
  //your app definition
  postgres:
    build: .

Answer 2

Pull the postgres image

docker pull postges:14.2

Create the service with the below command

docker service create --name postgres --network my_overlay --env "POSTGRES_PASSWORD=password" --publish 5432:5432 postgres:14.2

Try to connect using userName as postgres and password as password to the default postgres db.

jdbc:postgresql://127.0.0.1:5432/postgres // JDBC connection