如何对现有数据使用PostgreSQL容器？ [英] How to use a PostgreSQL container with existing data?

问题描述

我正在尝试设置PostgreSQL容器（ https://hub.docker.com/_ / postgres / ）。我有一些来自当前PostgreSQL实例的数据。我从 / var / lib / postgresql / data 复制了它，并想将其设置为PostgreSQL容器的卷。

I am trying to set up a PostgreSQL container (https://hub.docker.com/_/postgres/). I have some data from a current PostgreSQL instance. I copied it from /var/lib/postgresql/data and want to set it as a volume to a PostgreSQL container.

我从docker-compose.yml文件中获取有关PostgreSQL的部分：

My part from docker-compose.yml file about PostgreSQL:

db:
    image: postgres:9.4
    ports:
        - 5432:5432
    environment:
        POSTGRES_PASSWORD: postgres
        POSTGRES_USER: postgres
        PGDATA : /var/lib/postgresql/data
    volumes:
        - /projects/own/docker_php/pgdata:/var/lib/postgresql/data

当我制作docker-compose时，我收到以下消息：

When I make docker-compose up I get this message:

db_1  | initdb: directory "/var/lib/postgresql/data" exists but is not empty
db_1  | If you want to create a new database system, either remove or empty
db_1  | the directory "/var/lib/postgresql/data" or run initdb
db_1  | with an argument other than "/var/lib/postgresql/data".

我试图从容器创建自己的映像，所以我的Dockerfile是：

I tried to create my own image from the container, so my Dockerfile is:

FROM postgres:9.4
COPY pgdata /var/lib/postgresql/data

但是我遇到了同样的错误，我在做什么错？

But I got the same error, what am I doing wrong?

我使用pg_dumpall获得了SQL，并将其放在/docker-entrypoint-initdb.d中，但是每次我 docker-compose up 时都会执行此文件。

I got SQL using pg_dumpall and put it in /docker-entrypoint-initdb.d, but this file executes every time I do docker-compose up.

推荐答案

要基于irakli的答案，请使用以下更新的解决方案：

To build on irakli's answer, here's an updated solution:

• 使用更新的版本2 Docker Compose文件


• 单独的卷部分


• 已删除其他设置

• use newer version 2 Docker Compose file
• separate volumes section
• extra settings deleted

version: '2'

services:
  postgres9:
    image: postgres:9.4
    expose:
      - 5432
    volumes:
      - data:/var/lib/postgresql/data

volumes:
  data: {}

启动Postgres数据库服务器：

demo

Start Postgres database server:

$ docker-compose up

显示数据库中的所有表。在另一个终端中，与容器的Postgres对话：

Show all tables in the database. In another terminal, talk to the container's Postgres:

$ docker exec -it $(docker-compose ps -q postgres9 ) psql -Upostgres -c '\z'

由于数据库为空白，因此不会显示任何内容。创建表：

It'll show nothing, as the database is blank. Create a table:

$ docker exec -it $(docker-compose ps -q postgres9 ) psql -Upostgres -c 'create table beer()'

列出新创建的表：

$ docker exec -it $(docker-compose ps -q postgres9 ) psql -Upostgres -c '\z'

                         Access privileges
 Schema |   Name    | Type  | Access privileges | Column access privileges 
--------+-----------+-------+-------------------+--------------------------
 public | beer      | table |                   | 

是的！现在，我们使用共享存储卷启动了Postgres数据库，并在其中存储了一些数据。下一步是检查服务器停止后数据是否仍然存在。

Yay! We've now started a Postgres database using a shared storage volume, and stored some data in it. Next step is to check that the data actually sticks around after the server stops.

现在，杀死Postgres服务器容器：

Now, kill the Postgres server container:

$ docker-compose stop

启动再次使用Postgres容器：

Start up the Postgres container again:

$ docker-compose up

我们希望数据库服务器将重新使用存储，因此我们非常重要的数据仍然存在。检查：

We expect that the database server will re-use the storage, so our very important data is still there. Check:

$ docker exec -it $(docker-compose ps -q postgres9 ) psql -Upostgres -c '\z'
                         Access privileges
 Schema |   Name    | Type  | Access privileges | Column access privileges 
--------+-----------+-------+-------------------+--------------------------
public | beer      | table |                   | 

我们已成功使用新型Docker Compose文件使用外部数据运行Postgres数据库

We've successfully used a new-style Docker Compose file to run a Postgres database using an external data volume, and checked that it keeps our data safe and sound.

首先，进行备份，将数据存储在主机上：

First, make a backup, storing our data on the host:

$ docker exec -it $(docker-compose ps -q postgres9 ) pg_dump -Upostgres > backup.sql

从访客数据库中删除数据：

Zap our data from the guest database:

$ docker exec -it $(docker-compose ps -q postgres9 ) psql -Upostgres -c 'drop table beer'

将备份（存储在主机上）恢复到Postgres容器中。

Restore our backup (stored on the host) into the Postgres container.

注意：使用 exec -i，不 -it，否则将出现输入设备不是TTY错误。

Note: use "exec -i", not "-it", otherwise you'll get a "input device is not a TTY" error.

$ docker exec -i $(docker-compose ps -q postgres9 ) psql -Upostgres < backup.sql

列出表以验证还原是否有效：

List the tables to verify the restore worked:

$ docker exec -it $(docker-compose ps -q postgres9 ) psql -Upostgres -c '\z'
                         Access privileges
Schema |   Name    | Type  | Access privileges | Column access privileges 
--------+-----------+-------+-------------------+--------------------------
public | beer      | table |                   | 

总而言之，我们已验证可以启动数据库，并且数据在重新启动后仍然存在，我们可以从主机将备份还原到其中。

To sum up, we've verified that we can start a database, the data persists after a restart, and we can restore a backup into it from the host.

感谢Tomasz！

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