在 docker-compose 中运行的 Postgres 无法将数据写入已安装的卷

Question

Description

I am running a Postgres container in docker-compose. I am mounting the /data directory needed by Postgres into the container using a volume in the docker-compose.yml below.

Qualifications

1. The Postgres user must be called graph-node and create a database called graph-node
2. I delete the data/postgres/ folder before each docker-compose up using the boot.sh script below for application-specific reasons. Just know that /data/postgres is re-created on each run of docker-compose up .

Expected Behavior Postgres boots and writes all files it needs to the mounted /data/postgres volume.

Actual Behavior Postgres boots fine, but writes nothing to the volume.

Possible Reasons

This feels like a read/write permissions problem? I've added :rw in the third column of the volume as suggested, still no cigar. I run chmod -R a+rwx./data on the data dir to get access to all files recursively.

The oddest thing to is that if I manually run chmod -R a+rwx./data after booting, Postgres suddenly IS able to write to the directory all needed files. But if I run this before it's created as seen below (recursively for all things in /data ) it does not work.

Files

boot.sh

# Check for data/ dir. If found, make it recursively rwx for all users. Otherwise, create it and make it recursively rwx for all users.

if [ -d "./data" ]
then
    chmod -R a+rwx ./data
else
    mkdir data
    chmod -R a+rwx ./data
fi

if [ -d "./data/postgres" ]
then
    rm -rf data/postgres
else
    echo "No data/postgres dir found. Proceeding"
fi

docker-compose -f docker-compose.yml up

docker-compose.yml

version: "3"
services:
  postgres:
    image: postgres
    ports:
      - '5432:5432'
    command:
      [
        "postgres",
        "-cshared_preload_libraries=pg_stat_statements"
      ]
    environment:
      POSTGRES_USER: graph-node
      POSTGRES_PASSWORD: let-me-in
      POSTGRES_DB: graph-node
    volumes:
      - ./data/postgres:/var/lib/postgresql/data:rw

Machine + Software Specs

Operating System: Windows 10, WSL2, Ubuntu

Docker Version: 20.10.7 (running directly on the machine since it's Ubuntu, NOT in Docker Desktop like on a Mac)

Answer 1

have you run this script as an elevated user? specifically sudo?

Answer 2

Well, not exactly an answer, but because I only needed one-run ephemeral storage for Postgres (I was deleting the data/ dir between runs anyways) I solved the problem by just removing the external volume and letting Postgres write data into the container itself, where it surely had privileges.