CODEWITHSUNDEEP
postgresqldockerdocker-composedockerfile
ARYA
ARYA

Reputation: 243

Volume mount in docker for postgres data

I am trying to insert data into postgres using docker.

I have a folder in my code named data which has insert commands and has one file named init.sql.
I want to insert the data from init.sql present in folder data to tables present in docker.

version: '3.1'

services:
  postgres:  
    image: postgres:11.6-alpine 
    restart: always
    ports:
      - "5432:5432"
    environment:
      POSTGRES_PORT: 5432
    volumes:
      - ./tables:/docker-entrypoint-initdb.d/
      - ./data:/var/lib/postgresql/data
volumes:
  data: {}

I am trying this but I get the error:

initdb: directory "/var/lib/postgresql/data" exists but is not empty

I think I am not using the correct use case, I am new to docker compose.
But is there any way, my use case can get satisfied?

Upvotes: 2

Views: 12862

Answers (2)

Rafs
Rafs

Reputation: 814

In my case, I was running a container using a non-empty host directory which caused issues on initialisation (in init.sql):

> docker run --name pg --env POSTGRES_PASSWORD='pwd000' --env POSTGRES_USER='John' --env POSTGRES_DB='db' --publish 5432:5432 --volume ~/DockerDataVols/:/var/lib/postgresql/data
initdb: error: directory "/var/lib/postgresql/data" exists but is not empty
It contains a dot-prefixed/invisible file, perhaps due to it being a mount point.
Using a mount point directly as the data directory is not recommended.
Create a subdirectory under the mount point.

I deleted and recreated the host's folder and the error disappeared:

rm -rf ~/DockerDataVols

Upvotes: 0

β.εηοιτ.βε
β.εηοιτ.βε

Reputation: 39334

This is caused by an improper usage of the volumes syntax for your named volume.
In order to mount a named volume you have to just use its name like this:

    volumes:
      - data:/var/lib/postgresql/data

If your syntax begins with a . then it will be a bind mount from your host.

    volumes:
      - ./data:/var/lib/postgresql/data

The above code is mounting the host folder data relative to where you your docker-compose.yml is located.

This docker-compose.yml should do what you expect.

version: '3.1'

services:
  postgres:  
    image: postgres:11.6-alpine 
    restart: always
    ports:
      - "5432:5432"
    environment:
      POSTGRES_PORT: 5432
    volumes:
      - ./tables:/docker-entrypoint-initdb.d/
      - data:/var/lib/postgresql/data
volumes:
  data:

If for some reason your volume has been created already, with an empty or no database, your first step should be running:

docker-compose down --volumes

From the documentation:

-v, --volumes           Remove named volumes declared in the `volumes`
                        section of the Compose file and anonymous volumes
                        attached to containers.

From: https://docs.docker.com/compose/reference/down/

Upvotes: 2

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