Docker Postgres psql connection: FATAL: role "..." does not exist

I am using docker-compose to build a node express & Postgres application.

Problem
I cannot enter the container with psql to inspect the tables but my initial migration is logging that there was a successful migration.

--- EDIT --- Codebase --- END EDIT ---

Running Containers

note: the db is immediately shutting down and this might be the reason my psql is failing while the migration (which is creating a new connection) is working??

## -- LOG FROM RUNNING DB CONTAINER -- ##

2021-12-04 22:08:27.683 UTC [1] LOG:  listening on IPv4 address "0.0.0.0", port 5432

2021-12-04 22:08:27.683 UTC [1] LOG:  listening on IPv6 address "::", port 5432

2021-12-04 22:08:27.688 UTC [1] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"

2021-12-04 22:08:27.723 UTC [76] LOG:  database system was shut down at 2021-12-04 22:08:27 UTC

2021-12-04 22:08:27.734 UTC [1] LOG:  database system is ready to accept connections

✅ Successful Migration Command
docker exec reactquery_demo-backend-1 npm run migrate

❌ Failed psql Command(s)

1. trying to connect to db w/ docker user: psql -p 5432 -d reactquery_demo_db -U docker
2. trying to connect to db container w/ docker user:psql -p 5432 -d reactquery_demo-db-1 -U docker

THE ERROR:
psql: error: connection to server on socket "/tmp/.s.PGSQL.5432" failed: FATAL: role "docker" does not exist

• I have seen posts about this being caused by the fact that a POSTGRES_USER is not added in the docker-compose but I have that in mine (as shown below)
• I have also tried:
  • uninstalling / reinstalling / upgrading postgresql w/ homebrew
  • running rm /usr/local/var/postgres/postmaster.pid and then restarting Postgres w/ homebrew
  • stopping the homebrew Postgres processes completely so that is does not conflict with docker Postgres??
    • when I do this I get the following error: psql: error: connection to server on socket "/tmp/.s.PGSQL.5432" failed: No such file or directory Is the server running locally and accepting connections on that socket?

Repo Structure

Package.json

{
  "name": "ReactQueryDemo",
  "version": "0.0.1",
  "description": "Simple Overview of React Query for Weekly Dev Meeting",
  "main": "index.js",
  "scripts": {
    "dev": "node index.js",
    "dev:watch": "nodemon index.js",
    "migrate": "node db/scripts/migrate.js"
  },
  "dependencies": {
    "express": "^4.17.1",
    "knex": "^0.95.14",
    "pg": "^8.7.1"
  }
}

Docker Compose

version: '3.8'

services:
  backend: 
    build: ./backend
    ports: 
      - '8080:8080'
    depends_on:
      - db

  db:
    image: 'postgres'
    ports: 
      - '5432:5432'
    environment:
      - POSTGRES_PASSWORD=password
      - POSTGRES_USER=docker
      - POSTGRES_DB=react_query_demo_db
    volumes: 
      - data:/var/lib/postgresql/data

volumes:
  data:

Dockerfile

FROM node:17

WORKDIR /backend

# copy everything from local backend dir
# into your current working directory in
# the container: /backend
COPY . .

# install dependencies in the container
# the .dockerignore does not copy the 
# node_modules || Dockerfile itself
RUN npm i

CMD ["npm", "run", "dev"]

Backend Index

// server
const server = require("./api/server.js");

// port
const PORT = process.env.PORT || 8080;

// listening
server.listen(PORT, () => {
  console.log(`*** \n\tServer listening on http://0.0.0.0:${PORT}\n***`)
});

Server

// import packages
const express = require('express')

// import routes

// create server
const server = express()
// configure server
server.use(express.json())

// configure routing

// base route
server.get('/', async(req,res) => {
  console.log('React Query Demo Server Running')
  res.json({ status: "SUCCESS", message: "React Query Demo Server Running" })
})

// exports
module.exports = server

Database Index

// imports
const knex = require('knex')

module.exports = knex({
  client: 'postgres',
  connection: {
    host: 'db',             // this is the name of the service in the docker-compose
    user: 'docker',
    password: 'password',
    database: 'react_query_demo_db'     
  }
})